!1397 openGauss支持在线reindex

Merge pull request !1397 from 花花怪/master

src/bin/psql/common.cpp

@@ -2014,6 +2014,20 @@ static bool command_no_begin(const char* query)
             return true;
         if (wordlen == 10 && pg_strncasecmp(query, "tablespace", 10) == 0)
             return true;
+        if (wordlen == 5 && (pg_strncasecmp(query, "index", 5) == 0 || pg_strncasecmp(query, "table", 5) == 0)) {
+            query += wordlen;
+            query = skip_white_space(query);
+            wordlen = 0;
+            while (isalpha((unsigned char) query[wordlen]))
+                wordlen += PQmblen(&query[wordlen], pset.encoding);
+
+            /*
+             * REINDEX [ TABLE | INDEX ] CONCURRENTLY are not allowed 
+             * in xacts.
+             */
+            if(wordlen == 12 && pg_strncasecmp(query, "concurrently", 12) == 0)
+                return true;
+        }
         return false;
     }
 
@@ -2639,4 +2653,4 @@ char* GetEnvStr(const char* env)
         }
     }
     return NULL;
-}
+}

src/bin/psql/tab-complete.cpp

@@ -2638,10 +2638,18 @@ static char** PsqlCompletion(const char *text, int start, int end)
         COMPLETE_WITH_LIST(listReindex);
     } else if (pg_strcasecmp(PREV2_WD, "REINDEX") == 0) {
         if (pg_strcasecmp(PREV_WD, "TABLE") == 0)
-            COMPLETE_WITH_SCHEMA_QUERY(Query_for_list_of_tm, NULL);
+            COMPLETE_WITH_SCHEMA_QUERY(Query_for_list_of_tm, " UNION SELECT 'CONCURRENTLY'");
         else if (pg_strcasecmp(PREV_WD, "INDEX") == 0)
-            COMPLETE_WITH_SCHEMA_QUERY(Query_for_list_of_indexes, NULL);
+            COMPLETE_WITH_SCHEMA_QUERY(Query_for_list_of_indexes, " UNION SELECT 'CONCURRENTLY'");
         else if (pg_strcasecmp(PREV_WD, "SYSTEM") == 0 || pg_strcasecmp(PREV_WD, "DATABASE") == 0)
+            COMPLETE_WITH_QUERY(Query_for_list_of_databases " UNION SELECT 'CONCURRENTLY'");
+    } else if (pg_strcasecmp(PREV3_WD, "REINDEX") == 0) {
+        if (pg_strcasecmp(PREV2_WD, "TABLE") == 0 && pg_strcasecmp(PREV_WD, "CONCURRENTLY") == 0)
+            COMPLETE_WITH_SCHEMA_QUERY(Query_for_list_of_tm, NULL);
+        else if (pg_strcasecmp(PREV2_WD, "INDEX") == 0 && pg_strcasecmp(PREV_WD, "CONCURRENTLY") == 0)
+            COMPLETE_WITH_SCHEMA_QUERY(Query_for_list_of_indexes, NULL);
+        else if ((pg_strcasecmp(PREV2_WD, "SYSTEM") == 0 || pg_strcasecmp(PREV2_WD, "DATABASE") == 0) && 
+            pg_strcasecmp(PREV_WD, "CONCURRENTLY") == 0)
             COMPLETE_WITH_QUERY(Query_for_list_of_databases);
     }
 

src/bin/scripts/reindexdb.cpp

@@ -13,11 +13,11 @@
 #include "dumputils.h"
 
 static void reindex_one_database(const char* name, const char* dbname_tem, const char* type, const char* host,
-    const char* port, const char* username, enum trivalue prompt_password, const char* progname_tem, bool echo);
+    const char* port, const char* username, enum trivalue prompt_password, const char* progname_tem, bool echo, bool concurrently);
 static void reindex_all_databases(const char* maintenance_db, const char* host, const char* port, const char* username,
-    enum trivalue prompt_password, const char* progname_tem, bool echo, bool quiet);
+    enum trivalue prompt_password, const char* progname_tem, bool echo, bool quiet, bool concurrently);
 static void reindex_system_catalogs(const char* dbname_tem, const char* host, const char* port, const char* username,
-    enum trivalue prompt_password, const char* progname_tem, bool echo);
+    enum trivalue prompt_password, const char* progname_tem, bool echo, bool concurrently);
 static void help(const char* progname_tem);
 
 int main(int argc, char* argv[])
@@ -34,6 +34,7 @@ int main(int argc, char* argv[])
         {"system", no_argument, NULL, 's'},
         {"table", required_argument, NULL, 't'},
         {"index", required_argument, NULL, 'i'},
+        {"concurrently", no_argument, NULL, 1}
         {"maintenance-db", required_argument, NULL, 2},
         {NULL, 0, NULL, 0}};
 
@@ -51,6 +52,7 @@ int main(int argc, char* argv[])
     bool alldb = false;
     bool echo = false;
     bool quiet = false;
+    bool concurrently = false;
     const char* table = NULL;
     const char* index = NULL;
 
@@ -98,6 +100,9 @@ int main(int argc, char* argv[])
             case 'i':
                 index = optarg;
                 break;
+            case 1:
+                concurrently = true;
+                break;
             case 2:
                 maintenance_db = optarg;
                 break;
@@ -142,7 +147,7 @@ int main(int argc, char* argv[])
             exit(1);
         }
 
-        reindex_all_databases(maintenance_db, host, port, username, prompt_password, progname_tem, echo, quiet);
+        reindex_all_databases(maintenance_db, host, port, username, prompt_password, progname_tem, echo, quiet, concurrently);
     } else if (syscatalog) {
         if (table != NULL) {
             fprintf(stderr, _("%s: cannot reindex a specific table and system catalogs at the same time\n"), progname_tem);
@@ -162,7 +167,7 @@ int main(int argc, char* argv[])
                 dbname_tem = get_user_name(progname_tem);
         }
 
-        reindex_system_catalogs(dbname_tem, host, port, username, prompt_password, progname_tem, echo);
+        reindex_system_catalogs(dbname_tem, host, port, username, prompt_password, progname_tem, echo, concurrently);
     } else {
         if (dbname_tem == NULL) {
             if (getenv("PGDATABASE") != NULL)
@@ -174,19 +179,19 @@ int main(int argc, char* argv[])
         }
 
         if (index != NULL)
-            reindex_one_database(index, dbname_tem, "INDEX", host, port, username, prompt_password, progname_tem, echo);
+            reindex_one_database(index, dbname_tem, "INDEX", host, port, username, prompt_password, progname_tem, echo, concurrently);
         if (table != NULL)
-            reindex_one_database(table, dbname_tem, "TABLE", host, port, username, prompt_password, progname_tem, echo);
+            reindex_one_database(table, dbname_tem, "TABLE", host, port, username, prompt_password, progname_tem, echo, concurrently);
         /* reindex database only if index or table is not specified */
         if (index == NULL && table == NULL)
-            reindex_one_database(dbname_tem, dbname_tem, "DATABASE", host, port, username, prompt_password, progname_tem, echo);
+            reindex_one_database(dbname_tem, dbname_tem, "DATABASE", host, port, username, prompt_password, progname_tem, echo, concurrently);
     }
 
     exit(0);
 }
 
 static void reindex_one_database(const char* name, const char* dbname_tem, const char* type, const char* host,
-    const char* port, const char* username, enum trivalue prompt_password, const char* progname_tem, bool echo)
+    const char* port, const char* username, enum trivalue prompt_password, const char* progname_tem, bool echo, bool concurrently)
 {
     PQExpBufferData sql;
 
@@ -194,13 +199,15 @@ static void reindex_one_database(const char* name, const char* dbname_tem, const
 
     initPQExpBuffer(&sql);
 
-    appendPQExpBuffer(&sql, "REINDEX");
-    if (strcmp(type, "TABLE") == 0)
-        appendPQExpBuffer(&sql, " TABLE %s", name);
-    else if (strcmp(type, "INDEX") == 0)
-        appendPQExpBuffer(&sql, " INDEX %s", name);
+    appendPQExpBuffer(&sql, "REINDEX ");
+    appendPQExpBuffer(&sql, type);
+    appendPQExpBuffer(&sql," ");
+    if(concurrently)
+        appendPQExpBuffer(&sql,"CONCURRENTLY ");
+    if (strcmp(type, "TABLE") == 0 || strcmp(type, "INDEX") == 0)
+        appendPQExpBuffer(&sql, name);
     else if (strcmp(type, "DATABASE") == 0)
-        appendPQExpBuffer(&sql, " DATABASE %s", fmtId(name));
+        appendPQExpBuffer(&sql, fmtId(name));
     appendPQExpBuffer(&sql, ";\n");
 
     conn = connectDatabase(dbname_tem, host, port, username, prompt_password, progname_tem, false);
@@ -230,7 +237,7 @@ static void reindex_one_database(const char* name, const char* dbname_tem, const
 }
 
 static void reindex_all_databases(const char* maintenance_db, const char* host, const char* port, const char* username,
-    enum trivalue prompt_password, const char* progname_tem, bool echo, bool quiet)
+    enum trivalue prompt_password, const char* progname_tem, bool echo, bool quiet, bool concurrently)
 {
     PGconn* conn = NULL;
     PGresult* result = NULL;
@@ -248,14 +255,14 @@ static void reindex_all_databases(const char* maintenance_db, const char* host,
             fflush(stdout);
         }
 
-        reindex_one_database(dbname_tem, dbname_tem, "DATABASE", host, port, username, prompt_password, progname_tem, echo);
+        reindex_one_database(dbname_tem, dbname_tem, "DATABASE", host, port, username, prompt_password, progname_tem, echo, concurrently);
     }
 
     PQclear(result);
 }
 
 static void reindex_system_catalogs(const char* dbname_tem, const char* host, const char* port, const char* username,
-    enum trivalue prompt_password, const char* progname_tem, bool echo)
+    enum trivalue prompt_password, const char* progname_tem, bool echo, bool concurrently)
 {
     PQExpBufferData sql;
 
@@ -263,7 +270,11 @@ static void reindex_system_catalogs(const char* dbname_tem, const char* host, co
 
     initPQExpBuffer(&sql);
 
-    appendPQExpBuffer(&sql, "REINDEX SYSTEM %s;\n", dbname_tem);
+    appendPQExpBuffer(&sql, "REINDEX SYSTEM ");
+    if(concurrently)
+        appendPQExpBuffer(&sql,"CONCURRENTLY ");
+    appendPQExpBuffer(&sql, "%s;\n", dbname_tem);
+
 
     conn = connectDatabase(dbname_tem, host, port, username, prompt_password, progname_tem, false);
     if (!executeMaintenanceCommand(conn, sql.data, echo)) {
@@ -282,6 +293,7 @@ static void help(const char* progname_tem)
     printf(_("  %s [OPTION]... [DBNAME]\n"), progname_tem);
     printf(_("\nOptions:\n"));
     printf(_("  -a, --all                 reindex all databases\n"));
+    printf(_("  --concurrently        reindex concurrently\n"));
     printf(_("  -d, --dbname=DBNAME       database to reindex\n"));
     printf(_("  -e, --echo                show the commands being sent to the server\n"));
     printf(_("  -i, --index=INDEX         recreate specific index only\n"));

src/common/backend/catalog/dependency.cpp

@@ -194,6 +194,9 @@ extern char* pg_get_functiondef_worker(Oid funcid, int* headerlines);
  * a column default is dropped as an intermediate step while adding a new one,
  * that's an internal operation.  On the other hand, when the we drop something
  * because the user issued a DROP statement against it, that's not internal.
+ * 
+ * PERFORM_DELETION_CONCURRENT_LOCK: perform the drop normally but with a lock
+ * as if it were concurrent. This is used by REINDEX CONCURRENTLY
  */
 void performDeletion(const ObjectAddress* object, DropBehavior behavior, int flags)
 {
@@ -1167,9 +1170,10 @@ static void doDeletion(const ObjectAddress* object, int flags)
 
             if (relKind == RELKIND_INDEX || relKind == RELKIND_GLOBAL_INDEX) {
                 bool concurrent = (((uint32)flags & PERFORM_DELETION_CONCURRENTLY) == PERFORM_DELETION_CONCURRENTLY);
+                bool concurrent_lock_mode = (((uint32)flags & PERFORM_DELETION_CONCURRENTLY_LOCK) == PERFORM_DELETION_CONCURRENTLY_LOCK);
 
                 Assert(object->objectSubId == 0);
-                index_drop(object->objectId, concurrent);
+                index_drop(object->objectId, concurrent,concurrent_lock_mode);/*change for index concurrent*/
             } else {
                 /*
                  * relation_open() must be before the heap_drop_with_catalog(). If you reload

src/common/backend/catalog/index.cpp

@@ -48,6 +48,7 @@
 #include "catalog/pg_tablespace.h"
 #include "catalog/pg_trigger.h"
 #include "catalog/pg_type.h"
+#include "catalog/pg_description.h"
 #include "catalog/storage.h"
 #include "catalog/storage_gtt.h"
 #include "commands/tablecmds.h"
@@ -799,9 +800,9 @@ Oid index_create(Relation heapRelation, const char *indexRelationName, Oid index
 
     /*
      * concurrent index build on a system catalog is unsafe because we tend to
-     * release locks before committing in catalogs
+     * release locks before committing in catalogs.
      */
-    if (concurrent && IsSystemRelation(heapRelation))
+    if (concurrent && IsCatalogRelation(heapRelation))
         ereport(ERROR,
             (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
                 errmsg("concurrent index creation on system catalog tables is not supported")));
@@ -1306,6 +1307,672 @@ Oid partition_index_create(const char* partIndexName, /* the name of partition i
     return indexid;
 }
 
+/*
+ * index_concurrently_create_copy
+ * 
+ * Create concurrently an index based on the definition of the one provided 
+ * by caller. The index is inserted into catalogs and needs to be built later
+ * on. This is called during concurrent reindex processing.
+ */
+Oid index_concurrently_create_copy(Relation heapRelation, Oid oldIndexId, const char* newName)
+{
+    Relation indexRelation;
+    IndexInfo* indexInfo;
+    Oid newIndexId = InvalidOid;
+    HeapTuple indexTuple, classTuple;
+    Form_pg_index indexForm;
+    Datum indclassDatum, colOptionDatum, optionDatum;
+    oidvector* indclass;
+    int2vector* indcoloptions;
+    bool isnull;
+    List* indexColNames = NIL;
+    bool isprimary;
+
+    indexRelation = index_open(oldIndexId, RowExclusiveLock);
+
+    /* New index uses the same index information as old index */
+    indexInfo = BuildIndexInfo(indexRelation);
+
+    /* Get the array of class and column options IDs from index info */
+    indexTuple = SearchSysCache1(INDEXRELID, ObjectIdGetDatum(oldIndexId));
+    if(!HeapTupleIsValid(indexTuple))
+        elog(ERROR, "cache lookup failed for index %u", oldIndexId);
+    indclassDatum = SysCacheGetAttr(INDEXRELID, indexTuple, Anum_pg_index_indclass, &isnull);
+    Assert(!isnull);
+    indclass = (oidvector*) DatumGetPointer(indclassDatum);
+
+    colOptionDatum = SysCacheGetAttr(INDEXRELID, indexTuple, Anum_pg_index_indoption, &isnull);
+    Assert(!isnull);
+    indcoloptions = (int2vector*) DatumGetPointer(colOptionDatum);
+
+    /* Get index info about primary */
+    indexForm = (Form_pg_index) GETSTRUCT(indexTuple);
+    isprimary = indexForm->indisprimary;
+
+    /* Fetch options of index if any */
+    classTuple = SearchSysCache1(RELOID, oldIndexId);
+    if(!HeapTupleIsValid(classTuple))
+        elog(ERROR, "cache lookup failed for relation %u", oldIndexId);
+    optionDatum = SysCacheGetAttr(RELOID, classTuple, Anum_pg_class_reloptions, &isnull);
+
+    /*
+     * Extract the list of column names to be used for the index
+     * creation
+     */
+    for (int i = 0; i < indexInfo->ii_NumIndexAttrs; i++)
+    {
+        TupleDesc indexTupDesc = RelationGetDescr(indexRelation);
+        Form_pg_attribute att = TupleDescAttr(indexTupDesc, i);
+
+        indexColNames = lappend(indexColNames, NameStr(att->attname));
+    }
+
+    /* Make the indexCreateExtraArgs */
+    IndexCreateExtraArgs extra;
+    SetIndexCreateExtraArgs(&extra, indexRelation->rd_rel->relcudescrelid, 
+                            (indexRelation->rd_rel->parttype == PARTTYPE_PARTITIONED_RELATION) ||
+                            (indexRelation->rd_rel->relkind == RELKIND_GLOBAL_INDEX),
+                            indexRelation->rd_rel->relkind == RELKIND_GLOBAL_INDEX);
+
+    /* Now create the new index */
+    newIndexId = index_create(heapRelation, 
+                                            newName, 
+                                            InvalidOid, 
+                                            InvalidOid, 
+                                            indexInfo,
+                                            indexColNames,
+                                            indexRelation->rd_rel->relam,
+                                            indexRelation->rd_rel->reltablespace,
+                                            indexRelation->rd_indcollation,
+                                            indclass->values,
+                                            indcoloptions->values,
+                                            optionDatum,
+                                            isprimary,
+                                            false,
+                                            false,
+                                            false,
+                                            true,
+                                            true,
+                                            true,
+                                            &extra
+                                            );
+    
+    /* Close the relations used and clean up */
+    index_close(indexRelation, NoLock);
+    ReleaseSysCache(indexTuple);
+    ReleaseSysCache(classTuple);
+
+    return newIndexId;
+}
+
+/*
+ * index_concurrently_build
+ * 
+ * Build index for a concurrent operation. Low-level locks are taken when
+ * this operation is performed to prevent only schema change, but they need
+ * to be kept until the end of the transaction performing this operation.
+ * 'indexOid' refers to an index relation OID already created as part of
+ * previous processing. and 'heapOid' refers to its parent heap relation.
+ */
+void index_concurrently_build(Oid heapRelationId, Oid indexRelationId, bool isPrimary, AdaptMem* memInfo, bool dbWide)
+{
+    Relation heapRel;
+    Relation indexRelation;
+    IndexInfo* indexInfo;
+
+    /* This had better make sure that a snapshot is active */
+    Assert(ActiveSnapshotSet());
+
+    /* Open and lock the parent heap relation */
+    heapRel =  heap_open(heapRelationId, ShareUpdateExclusiveLock);
+
+    /* And the target index relation */
+    indexRelation = index_open(indexRelationId, RowExclusiveLock);
+
+    /* We have to re-build the IndexInfo struct, since it was lost in commit */
+    indexInfo = BuildIndexInfo(indexRelation);
+    Assert(!indexInfo->ii_ReadyForInserts);
+    indexInfo->ii_Concurrent = true;
+    indexInfo->ii_BrokenHotChain = false;
+
+    /* workload client manager */
+    if (IS_PGXC_COORDINATOR && ENABLE_WORKLOAD_CONTROL) {
+        /* if operatorMem is already set, the mem check is already done */
+        if (memInfo != NULL && memInfo->work_mem == 0) {
+            EstIdxMemInfo(heapRel, NULL, &indexInfo->ii_desc, indexInfo, indexRelation->rd_am->amname.data);
+            if (dbWide) {
+                indexInfo->ii_desc.cost = g_instance.cost_cxt.disable_cost;
+                indexInfo->ii_desc.query_mem[0] = Max(STATEMENT_MIN_MEM * 1024, indexInfo->ii_desc.query_mem[0]);
+            }
+            WLMInitQueryPlan((QueryDesc*)&indexInfo->ii_desc, false);
+            dywlm_client_manager((QueryDesc*)&indexInfo->ii_desc, false);
+            AdjustIdxMemInfo(memInfo, &indexInfo->ii_desc);
+        }
+    } else if (IS_PGXC_DATANODE && memInfo != NULL && memInfo->work_mem > 0) {
+        indexInfo->ii_desc.query_mem[0] = memInfo->work_mem;
+        indexInfo->ii_desc.query_mem[1] = memInfo->max_mem;
+    }
+
+    /* Now build the index */
+    index_build(heapRel, NULL, indexRelation, NULL, indexInfo, isPrimary, false, INDEX_CREATE_NONE_PARTITION);
+
+    /* Close both the relations, but keep the locks */
+    heap_close(heapRel, NoLock);
+    index_close(indexRelation, NoLock);
+
+    /*
+     * Update the pg_index row to mark the index as ready for inserts, Once we
+     * commit this transaction, any new transactions that open the table must
+     * insert new entries into the index for insertions and non-HOT updates.
+     */
+    index_set_state_flags(indexRelationId, INDEX_CREATE_SET_READY);
+} 
+
+/*
+ * index_concurrently_swap
+ * Swap name, dependencies, and constraints of the old index over to the new
+ * index, while marking the old index as invalid and the new as valid.
+ */
+void index_concurrently_swap(Oid newIndexId, Oid oldIndexId, const char* oldName)
+{
+    Relation pg_class, pg_index, pg_constraint, pg_trigger;
+    Relation oldClassRel, newClassRel;
+    HeapTuple oldClassTuple, newClassTuple;
+    Form_pg_class oldClassForm, newClassForm;
+    HeapTuple oldIndexTuple, newIndexTuple;
+    Form_pg_index oldIndexForm, newIndexForm;
+    Oid indexConstraintOid;
+    List* constraintOids = NIL;
+    ListCell* lc;
+
+    /*
+     * Take a necessary lock on the old and new index before swaping them.
+     */
+    oldClassRel = relation_open(oldIndexId, ShareUpdateExclusiveLock);
+    newClassRel = relation_open(newIndexId, ShareUpdateExclusiveLock);
+
+    /* Now swap names and dependencies of those indexs */
+    pg_class = heap_open(RelationRelationId, RowExclusiveLock);
+
+    oldClassTuple = SearchSysCacheCopy1(RELOID, ObjectIdGetDatum(oldIndexId));
+    if(!HeapTupleIsValid(oldClassTuple))
+        elog(ERROR, "could not find tuple for relation %u", oldIndexId);
+
+    newClassTuple = SearchSysCacheCopy1(RELOID, ObjectIdGetDatum(newIndexId));
+    if(!HeapTupleIsValid(newClassTuple))
+        elog(ERROR, "could not find tuple for relation %u", newIndexId);
+    
+    oldClassForm = (Form_pg_class) GETSTRUCT(oldClassTuple);
+    newClassForm = (Form_pg_class) GETSTRUCT(newClassTuple);
+
+    /* Swap the name */
+    namestrcpy(&newClassForm->relname, NameStr(oldClassForm->relname));
+    namestrcpy(&oldClassForm->relname, oldName);
+
+    simple_heap_update(pg_class, &oldClassTuple->t_self, oldClassTuple);
+    CatalogUpdateIndexes(pg_class, oldClassTuple);
+    simple_heap_update(pg_class, &newClassTuple->t_self, newClassTuple);
+    CatalogUpdateIndexes(pg_class, newClassTuple);
+    
+    heap_freetuple(oldClassTuple);
+    heap_freetuple(newClassTuple);
+
+    /* Now swap index info */
+    pg_index = heap_open(IndexRelationId, RowExclusiveLock);
+
+    oldIndexTuple = SearchSysCacheCopy1(INDEXRELID, ObjectIdGetDatum(oldIndexId));
+    if (!HeapTupleIsValid(oldIndexTuple))
+        elog(ERROR, "could not find tuple for relation %u", oldIndexId);
+    newIndexTuple = SearchSysCacheCopy1(INDEXRELID, ObjectIdGetDatum(newIndexId));
+    if (!HeapTupleIsValid(newIndexTuple))
+        elog(ERROR, "could not find tuple for relation %u", newIndexId);
+
+    oldIndexForm = (Form_pg_index) GETSTRUCT(oldIndexTuple);
+    newIndexForm = (Form_pg_index) GETSTRUCT(newIndexTuple);
+
+    /*
+     * Copy constraint flags from the old index. This is safe because the old
+     * index guaranteed uniqueness.
+     */
+    newIndexForm->indisprimary = oldIndexForm->indisprimary;
+    oldIndexForm->indisprimary = false;
+    newIndexForm->indisexclusion = oldIndexForm->indisexclusion;
+    oldIndexForm->indisexclusion = false;
+    newIndexForm->indimmediate = oldIndexForm->indimmediate;
+    oldIndexForm->indimmediate = true;
+
+    /* Mark old index as valid and new as invalid as index_set_state_flags */
+    newIndexForm->indisvalid = true;
+    oldIndexForm->indisvalid = false;
+    oldIndexForm->indisclustered = false;
+
+    simple_heap_update(pg_index, &oldIndexTuple->t_self, oldIndexTuple);
+    CatalogUpdateIndexes(pg_index, oldIndexTuple);
+    simple_heap_update(pg_index, &newIndexTuple->t_self, newIndexTuple);
+    CatalogUpdateIndexes(pg_index, newIndexTuple);
+
+    heap_freetuple(oldIndexTuple);
+    heap_freetuple(newIndexTuple);
+
+    /*
+     * Move constraints and triggers over to the new index
+     */
+
+    constraintOids = get_index_ref_constraints(oldIndexId);
+
+    indexConstraintOid = get_index_constraint(oldIndexId);
+
+    if(OidIsValid(indexConstraintOid))
+        constraintOids = lappend_oid(constraintOids, indexConstraintOid);
+
+    pg_constraint = heap_open(ConstraintRelationId, RowExclusiveLock);
+    pg_trigger = heap_open(TriggerRelationId, RowExclusiveLock);
+
+    foreach(lc, constraintOids) {
+        HeapTuple constraintTuple, triggerTuple;
+        Form_pg_constraint conForm;
+        ScanKeyData key[1];
+        SysScanDesc scan;
+        Oid constraintOid = lfirst_oid(lc);
+
+        /* Move the constraint from the old to the new index */
+        constraintTuple = SearchSysCacheCopy1(CONSTROID, ObjectIdGetDatum(constraintOid));
+        if (!HeapTupleIsValid(constraintTuple))
+            elog(ERROR, "could not find tuple for constraint %u", constraintOid);
+        
+        conForm = (Form_pg_constraint) GETSTRUCT(constraintTuple);
+
+        if (conForm->conindid == oldIndexId)
+        {
+            conForm->conindid = newIndexId;
+
+            simple_heap_update(pg_constraint, &constraintTuple->t_self, constraintTuple);
+            CatalogUpdateIndexes(pg_constraint, constraintTuple);
+        }
+
+        heap_freetuple(constraintTuple);
+
+        /* Search for trigger records */
+        ScanKeyInit(&key[0], Anum_pg_trigger_tgconstraint, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(constraintOid));
+        
+        scan = systable_beginscan(pg_trigger, TriggerConstraintIndexId, true, NULL, 1, key);
+        
+        while (HeapTupleIsValid(triggerTuple = systable_getnext(scan)))
+        {
+            Form_pg_trigger tgForm = (Form_pg_trigger) GETSTRUCT(triggerTuple);
+
+            if (tgForm->tgconstrindid != oldIndexId)
+                continue;
+
+            /* Make a modifiable copy */
+            triggerTuple = heap_copytuple(triggerTuple);
+            tgForm = (Form_pg_trigger) GETSTRUCT(triggerTuple);
+
+            tgForm->tgconstrindid = newIndexId;
+
+            simple_heap_update(pg_trigger, &triggerTuple->t_self, triggerTuple);
+            CatalogUpdateIndexes(pg_trigger, triggerTuple);
+
+            heap_freetuple(triggerTuple);
+        }
+
+        systable_endscan(scan);
+    }
+
+    /*
+     * Move comment if any
+     */
+    
+    {
+        Relation description;
+        ScanKeyData skey[3];
+        SysScanDesc sd;
+        HeapTuple tuple;
+        Datum values[Natts_pg_description] = {0};
+        bool nulls[Natts_pg_description] = {0};
+        bool replaces[Natts_pg_description] = {0};
+
+        values[Anum_pg_description_objoid - 1] = ObjectIdGetDatum(newIndexId);
+        replaces[Anum_pg_description_objoid - 1] = true;
+
+        ScanKeyInit(&skey[0], Anum_pg_description_objoid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(oldIndexId));
+        ScanKeyInit(&skey[1], Anum_pg_description_classoid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(RelationRelationId));
+        ScanKeyInit(&skey[2], Anum_pg_description_objsubid, BTEqualStrategyNumber, F_INT4EQ, Int32GetDatum(0));
+
+        description = heap_open(DescriptionRelationId, RowExclusiveLock);
+
+        sd = systable_beginscan(description, DescriptionObjIndexId, true, NULL, 3, skey);
+
+        while ((tuple = systable_getnext(sd)) != NULL)
+        {
+            tuple = heap_modify_tuple(tuple, RelationGetDescr(description), values, nulls, replaces);
+            simple_heap_update(description, &tuple->t_self, tuple);
+            CatalogUpdateIndexes(description, tuple);
+            break;                    /* Assume there can be only one match */
+        }
+
+        systable_endscan(sd);
+        heap_close(description, NoLock);
+    }
+
+    /*
+     * Move all dependencies on the old index to the new one
+     */
+
+    if (OidIsValid(indexConstraintOid))
+    {
+        ObjectAddress myself, referenced;
+
+        /* Change to having the new index depend on the constraint */
+        deleteDependencyRecordsForClass(RelationRelationId, oldIndexId, ConstraintRelationId, DEPENDENCY_INTERNAL);
+        myself.classId = RelationRelationId;
+        myself.objectId = newIndexId;
+        myself.objectSubId = 0;
+
+        referenced.classId = ConstraintRelationId;
+        referenced.objectId = indexConstraintOid;
+        referenced.objectSubId = 0;
+
+        recordDependencyOn(&myself, &referenced, DEPENDENCY_INTERNAL);
+    }
+
+    changeDependenciesOn(RelationRelationId, oldIndexId, newIndexId);
+
+    /*
+     * Copy over statistics from old to new index
+     */
+    {
+        PgStat_StatTabKey tabkey;
+        PgStat_StatTabEntry *tabentry;
+
+        tabkey.tableid = oldIndexId;
+        tabentry = pgstat_fetch_stat_tabentry(&tabkey);
+        if (tabentry)
+        {
+            if (newClassRel->pgstat_info)
+            {
+                newClassRel->pgstat_info->t_counts.t_numscans = tabentry->numscans;
+                newClassRel->pgstat_info->t_counts.t_tuples_returned = tabentry->tuples_returned;
+                newClassRel->pgstat_info->t_counts.t_tuples_fetched = tabentry->tuples_fetched;
+                newClassRel->pgstat_info->t_counts.t_blocks_fetched = tabentry->blocks_fetched;
+                newClassRel->pgstat_info->t_counts.t_blocks_hit = tabentry->blocks_hit;
+                /* The data will be sent by the next pgstat_report_stat() call. */
+            }
+        }
+    }
+
+    /* Close relations */
+    heap_close(pg_class, RowExclusiveLock);
+    heap_close(pg_index, RowExclusiveLock);
+    heap_close(pg_constraint, RowExclusiveLock);
+    heap_close(pg_trigger, RowExclusiveLock);
+
+    /* The lock taken previously is not released until the end of transaction */
+    relation_close(oldClassRel, NoLock);
+    relation_close(newClassRel, NoLock);
+}
+
+/*
+ * index_concurrently_set_dead
+ * Perform the last invaildation stage of DROP INDEX CONCURRENTLY or REINDEX
+ * CONCURRENTLY before actually dropping index. After calling this
+ * functions, the index is seen by all the backends as dead. Low-level locks
+ * taken here are kept until the end of the transaction calling this function.
+ */
+void index_concurrently_set_dead(Oid heapId, Oid indexId)
+{
+    Relation userHeapRelation;
+    Relation userIndexRelation;
+
+    /*
+     * No more predicate locks will be acquired on this index, and we're
+     * about to stop doing inserts into the index which could show 
+     * conflicts with existing predicate locks, so now is the time to move
+     * them to the heap relation.
+     */
+    userHeapRelation = heap_open(heapId, ShareUpdateExclusiveLock);
+    userIndexRelation = index_open(indexId, ShareUpdateExclusiveLock);
+    TransferPredicateLocksToHeapRelation(userIndexRelation);
+
+    /*
+     * Now we are sure that nobody uses the index for queries; they just
+     * might have it open for updating it. So now we can unset indisready
+     * and set indisvalid, then wait till nobody could be using it at all
+     * anymore.
+     */
+    index_set_state_flags(indexId, INDEX_DROP_SET_DEAD);
+
+    /*
+     * Invalidate the relcache for the table, so that after this commit
+     * all sessions will refresh the table's index list.  Forgetting just
+     * the index's relcache entry is not enough.
+     */
+    CacheInvalidateRelcache(userHeapRelation);
+
+    /*
+     * Close the relations again, though still holding session lock
+     */
+    heap_close(userHeapRelation, NoLock);
+    index_close(userIndexRelation, NoLock);
+}
+
+/* 
+ * index_concurrently_part_create_copy
+ * 
+ * Create concurrently a part index based on the definition of the one provided
+ * by caller.  The index is inserted into catalogs and needs to be built later
+ * on. This is called during concurrent reindex partition processing.
+ */
+Oid index_concurrently_part_create_copy(Oid oldIndexPartId, const char* newName) {
+    Oid newIndexPartId = InvalidOid;
+    Oid heapPartId = InvalidOid;
+    Oid indexId = InvalidOid;
+    Oid heapId = InvalidOid;
+    Oid partitiontspid = InvalidOid;
+    Relation indexRelation = NULL;
+    Relation heapRelation = NULL;
+    Partition indexPart = NULL;
+    Partition heapPart = NULL;
+    HeapTuple indexPartTuple, classTuple;
+    Form_pg_partition indexPartForm;
+    Relation pg_partition_rel = NULL;
+    IndexInfo* indexInfo;
+    List* indexColNames = NIL;
+    bool isnull;
+    Datum optionDatum;
+
+    indexPartTuple = SearchSysCache1(PARTRELID, ObjectIdGetDatum(oldIndexPartId));
+    if(!HeapTupleIsValid(indexPartTuple)) {
+        ereport(ERROR, (errcode(ERRCODE_UNDEFINED_OBJECT), errmsg("cache lookup failed for partition index %u", oldIndexPartId)));
+    }
+    indexPartForm = (Form_pg_partition)GETSTRUCT(indexPartTuple);
+
+    heapPartId = indexPartForm->indextblid;
+    indexId = indexPartForm->parentid;
+    indexRelation = index_open(indexId, AccessShareLock);
+    heapId = indexRelation->rd_index->indrelid;
+    heapRelation = heap_open(heapId, AccessShareLock);
+    partitiontspid = indexPartForm->reltablespace;
+
+    heapPart = partitionOpen(heapRelation, heapPartId, ShareUpdateExclusiveLock);
+    indexPart = partitionOpen(indexRelation, oldIndexPartId, RowExclusiveLock);
+
+    indexInfo = BuildIndexInfo(indexRelation);
+
+    /* Fetch the options of index if any */
+    classTuple = SearchSysCache1(RELOID, indexId);
+    if(!HeapTupleIsValid(classTuple)) {
+        ereport(ERROR, (errcode(ERRCODE_UNDEFINED_OBJECT), errmsg("cache lookup failed for relation %u", indexId)));
+    }
+    optionDatum = SysCacheGetAttr(RELOID, classTuple, Anum_pg_class_reloptions, &isnull);
+
+    /*
+     * Extract the list of column names to be used for the index
+     * creation.
+     */
+    for(int i = 0; i < indexInfo->ii_NumIndexAttrs; i++) {
+        TupleDesc indexTupDesc = RelationGetDescr(indexRelation);
+        Form_pg_attribute att = TupleDescAttr(indexTupDesc, i);
+
+        indexColNames = lappend(indexColNames, NameStr(att->attname));
+    }
+
+    pg_partition_rel = heap_open(PartitionRelationId, RowExclusiveLock);
+
+    PartIndexCreateExtraArgs partExtra;
+    partExtra.existingPSortOid = indexPart->pd_part->relcudescrelid;
+
+    newIndexPartId = partition_index_create(newName, InvalidOid, heapPart, partitiontspid, indexRelation, heapRelation,
+                                            pg_partition_rel, indexInfo, indexColNames, optionDatum, true, &partExtra);
+
+    partitionClose(indexRelation, indexPart, NoLock);
+    partitionClose(heapRelation, heapPart, NoLock);
+    heap_close(pg_partition_rel, RowExclusiveLock);
+    heap_close(indexRelation, NoLock);
+    heap_close(heapRelation, NoLock);
+    ReleaseSysCache(indexPartTuple);
+    ReleaseSysCache(classTuple);
+
+    return newIndexPartId;
+}
+
+/* 
+ * index_concurrently_part_build
+ *
+ * Build partition index for a concurrent operation. Low-level locks are taken when
+ * this operation is performed to prevent only schema change, but they need
+ * to be kept until the end of the transaction performing this operation.
+ */
+void index_concurrently_part_build(Oid heapRelationId, Oid heapPartitionId, Oid indexRelationId, Oid IndexPartitionId, AdaptMem* memInfo, bool dbWide) {
+    Relation heapRelation;
+    Relation indexRelation;
+    Partition heapPartition;
+    Partition indexPartition;
+    IndexInfo* indexInfo;
+
+    /* Open and lock the parent heap relation and index relation */
+    heapRelation = heap_open(heapRelationId, AccessShareLock);
+    indexRelation = index_open(indexRelationId, AccessShareLock);
+
+    /* Open and lock the parent heap partition */
+    heapPartition = partitionOpen(heapRelation, heapPartitionId, ShareUpdateExclusiveLock);
+
+    /* Open and lock target index partition */
+    indexPartition = partitionOpen(indexRelation, IndexPartitionId, RowExclusiveLock);
+
+    /* We have to re-build the IndexInfo struct, since it was lost in commit */
+    indexInfo = BuildIndexInfo(indexRelation);
+    //Assert(!indexInfo->ii_ReadyForInserts); --part index indexInfo->ii_ReadyForInserts is false
+    indexInfo->ii_Concurrent = true;
+    indexInfo->ii_BrokenHotChain = false;
+
+    /* workload client manager */
+    if (IS_PGXC_COORDINATOR && ENABLE_WORKLOAD_CONTROL) {
+        /* if operatorMem is already set, the mem check is already done */
+        if (memInfo != NULL && memInfo->work_mem == 0) {
+            EstIdxMemInfo(heapRelation, NULL, &indexInfo->ii_desc, indexInfo, indexRelation->rd_am->amname.data);
+            if (dbWide) {
+                indexInfo->ii_desc.cost = g_instance.cost_cxt.disable_cost;
+                indexInfo->ii_desc.query_mem[0] = Max(STATEMENT_MIN_MEM * 1024, indexInfo->ii_desc.query_mem[0]);
+            }
+            WLMInitQueryPlan((QueryDesc*)&indexInfo->ii_desc, false);
+            dywlm_client_manager((QueryDesc*)&indexInfo->ii_desc, false);
+            AdjustIdxMemInfo(memInfo, &indexInfo->ii_desc);
+        }
+    } else if (IS_PGXC_DATANODE && memInfo != NULL && memInfo->work_mem > 0) {
+        indexInfo->ii_desc.query_mem[0] = memInfo->work_mem;
+        indexInfo->ii_desc.query_mem[1] = memInfo->max_mem;
+    }
+
+    /* Now build the index */
+    index_build(heapRelation, heapPartition, indexRelation, indexPartition, indexInfo, false, true, INDEX_CREATE_LOCAL_PARTITION);
+
+    /* Close the partitions and relations, but keep the locks */
+    partitionClose(heapRelation, heapPartition, NoLock);
+    partitionClose(indexRelation, indexPartition, NoLock);
+    heap_close(heapRelation, NoLock);
+    index_close(indexRelation, NoLock);
+}
+
+/* 
+ * index_concurrently_part_swap
+ *
+ * Swap name, dependencies, and constraints of the old index over to the new
+ * index, while marking the old index as invalid and the new as valid.
+ */
+void index_concurrently_part_swap(Relation indexRelation, Oid newIndexPartId, Oid oldIndexPartId, const char *oldName) {
+    Relation pg_partition;
+    Partition oldIndexPartition, newIndexPartition;
+    HeapTuple oldIndexPartTuple, newIndexPartTuple;
+    Form_pg_partition oldIndexPartForm, newIndexPartForm;
+
+    /*
+     * Take a necessary lock on the old and new index before swaping them.
+     */
+    oldIndexPartition = partitionOpen(indexRelation, oldIndexPartId, ShareUpdateExclusiveLock);
+    newIndexPartition = partitionOpen(indexRelation, newIndexPartId, ShareUpdateExclusiveLock);
+
+    /* Now swap names of those indexs */
+    pg_partition = heap_open(PartitionRelationId, RowExclusiveLock);
+
+    oldIndexPartTuple = SearchSysCache1(PARTRELID, ObjectIdGetDatum(oldIndexPartId));
+    if(!HeapTupleIsValid(oldIndexPartTuple))
+        elog(ERROR, "could not find tuple for relation %u", oldIndexPartId);
+    
+    newIndexPartTuple = SearchSysCache1(PARTRELID, ObjectIdGetDatum(newIndexPartId));
+    if(!HeapTupleIsValid(newIndexPartTuple))
+        elog(ERROR, "could not find tuple for relation %u", newIndexPartId);
+
+    oldIndexPartForm = (Form_pg_partition) GETSTRUCT(oldIndexPartTuple);
+    newIndexPartForm = (Form_pg_partition) GETSTRUCT(newIndexPartTuple);
+
+    /* Swap the name */
+    namestrcpy(&newIndexPartForm->relname, NameStr(oldIndexPartForm->relname));
+    namestrcpy(&oldIndexPartForm->relname, oldName);
+
+    /* Mark old index as invalid and new as valid */
+    newIndexPartForm->indisusable = true;
+    oldIndexPartForm->indisusable = false;
+
+    simple_heap_update(pg_partition, &oldIndexPartTuple->t_self, oldIndexPartTuple);
+    CatalogUpdateIndexes(pg_partition, oldIndexPartTuple);
+    simple_heap_update(pg_partition, &newIndexPartTuple->t_self, newIndexPartTuple);
+    CatalogUpdateIndexes(pg_partition, newIndexPartTuple);
+
+    ReleaseSysCache(oldIndexPartTuple);
+    ReleaseSysCache(newIndexPartTuple);
+    /*
+     * Copy over statistics from old to new index
+     */
+    {
+        PgStat_StatTabKey tabkey;
+        PgStat_StatTabEntry* tabentry;
+
+        tabkey.tableid = oldIndexPartId;
+        tabentry = pgstat_fetch_stat_tabentry(&tabkey);
+        if (tabentry)
+        {
+            if (newIndexPartition->pd_pgstat_info)
+            {
+                newIndexPartition->pd_pgstat_info->t_counts.t_numscans = tabentry->numscans;
+                newIndexPartition->pd_pgstat_info->t_counts.t_tuples_returned = tabentry->tuples_returned;
+                newIndexPartition->pd_pgstat_info->t_counts.t_tuples_fetched = tabentry->tuples_fetched;
+                newIndexPartition->pd_pgstat_info->t_counts.t_blocks_fetched = tabentry->blocks_fetched;
+                newIndexPartition->pd_pgstat_info->t_counts.t_blocks_hit = tabentry->blocks_hit;
+                /* The data will be sent by the next pgstat_report_stat() call. */
+            }
+        }
+    }
+
+    /* Close relation */
+    heap_close(pg_partition, RowExclusiveLock);
+
+    /* The lock taken previously is not released until the end of transaction */
+    partitionClose(indexRelation, oldIndexPartition, NoLock);
+    partitionClose(indexRelation, newIndexPartition, NoLock);
+}
+
+
 /*
  * index_constraint_create
  *
@@ -1519,7 +2186,7 @@ static void MotFdwDropForeignIndex(Relation userHeapRelation, Relation userIndex
  * NOTE: this routine should now only be called through performDeletion(),
  * else associated dependencies won't be cleaned up.
  */
-void index_drop(Oid indexId, bool concurrent)
+void index_drop(Oid indexId, bool concurrent, bool concurrent_lock_mode)
 {
     Oid heapId;
     Relation userHeapRelation;
@@ -1563,7 +2230,7 @@ void index_drop(Oid indexId, bool concurrent)
      * using it.)
      */
     heapId = IndexGetRelation(indexId, false);
-    lockmode = concurrent ? ShareUpdateExclusiveLock : AccessExclusiveLock;
+    lockmode = (concurrent || concurrent_lock_mode) ? ShareUpdateExclusiveLock : AccessExclusiveLock;
     userHeapRelation = heap_open(heapId, lockmode);
     userIndexRelation = index_open(indexId, lockmode);
 
@@ -1690,36 +2357,8 @@ void index_drop(Oid indexId, bool concurrent)
             old_lockholders++;
         }
 
-        /*
-         * No more predicate locks will be acquired on this index, and we're
-         * about to stop doing inserts into the index which could show
-         * conflicts with existing predicate locks, so now is the time to move
-         * them to the heap relation.
-         */
-        userHeapRelation = heap_open(heapId, ShareUpdateExclusiveLock);
-        userIndexRelation = index_open(indexId, ShareUpdateExclusiveLock);
-        TransferPredicateLocksToHeapRelation(userIndexRelation);
-
-        /*
-         * Now we are sure that nobody uses the index for queries; they just
-         * might have it open for updating it.	So now we can unset indisready
-         * and set indisvalid, then wait till nobody could be using it at all
-         * anymore.
-         */
-        index_set_state_flags(indexId, INDEX_DROP_SET_DEAD);
-
-        /*
-         * Invalidate the relcache for the table, so that after this commit
-         * all sessions will refresh the table's index list.  Forgetting just
-         * the index's relcache entry is not enough.
-         */
-        CacheInvalidateRelcache(userHeapRelation);
-
-        /*
-         * Close the relations again, though still holding session lock.
-         */
-        heap_close(userHeapRelation, NoLock);
-        index_close(userIndexRelation, NoLock);
+        /* Finish invalidation of index and mark it as dead */
+        index_concurrently_set_dead(heapId, indexId);
 
         /*
          * Again, commit the transaction to make the pg_index update visible
@@ -3793,7 +4432,7 @@ static void IndexCheckExclusion(Relation heapRelation, Relation indexRelation, I
  * making the table append-only by setting use_fsm).  However that would
  * add yet more locking issues.
  */
-void validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
+void validate_index(Oid heapId, Oid indexId, Snapshot snapshot, bool isPart)
 {
     Relation heapRelation, indexRelation;
     IndexInfo* indexInfo = NULL;
@@ -3803,10 +4442,27 @@ void validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
     int save_sec_context;
     int save_nestlevel;
 
-    /* Open and lock the parent heap relation */
-    heapRelation = heap_open(heapId, ShareUpdateExclusiveLock);
-    /* And the target index relation */
-    indexRelation = index_open(indexId, RowExclusiveLock);
+    /* these variants is used for part index */
+    Oid heapParentId, indexParentId;
+    Relation heapParentRel, indexParentRel;
+    Partition heapPartition, indexPartition;
+
+    if (isPart){
+        heapParentId = PartIdGetParentId(heapId, false);
+        heapParentRel = heap_open(heapParentId, AccessShareLock);
+        heapPartition = partitionOpen(heapParentRel, heapId, ShareUpdateExclusiveLock);
+        heapRelation = partitionGetRelation(heapParentRel, heapPartition);
+        indexParentId = PartIdGetParentId(indexId, false);
+        indexParentRel = index_open(indexParentId, AccessShareLock);
+        indexPartition = partitionOpen(indexParentRel, indexId, RowExclusiveLock);
+        indexRelation = partitionGetRelation(indexParentRel, indexPartition);
+    }
+    else {
+        /* Open and lock the parent heap relation */
+        heapRelation = heap_open(heapId, ShareUpdateExclusiveLock);
+        /* And the target index relation */
+        indexRelation = index_open(indexId, RowExclusiveLock);
+    }
 
     /*
      * Fetch info needed for index_insert.	(You might think this should be
@@ -3867,8 +4523,18 @@ void validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
     SetUserIdAndSecContext(save_userid, save_sec_context);
 
     /* Close rels, but keep locks */
-    index_close(indexRelation, NoLock);
-    heap_close(heapRelation, NoLock);
+    if (isPart) {
+        partitionClose(indexParentRel, indexPartition, NoLock);
+        partitionClose(heapParentRel, heapPartition, NoLock);
+        index_close(indexParentRel, NoLock);
+        heap_close(heapParentRel, NoLock);
+        releaseDummyRelation(&indexRelation);
+        releaseDummyRelation(&heapRelation);
+    }
+    else {
+        index_close(indexRelation, NoLock);
+        heap_close(heapRelation, NoLock);
+    }
 }
 
 /*
@@ -4190,6 +4856,51 @@ Oid IndexGetRelation(Oid indexId, bool missing_ok)
     return result;
 }
 
+/*
+ * PartIndexGetPartition: given an part index's relation OID, get the OID of the
+ * Partiton it is an index on. Uses the system cache.
+ */
+Oid PartIndexGetPartition(Oid partIndexId, bool missing_ok)
+{
+    HeapTuple tuple;
+    Form_pg_partition indexForm;
+    Oid result;
+
+    tuple = SearchSysCache1(PARTRELID, ObjectIdGetDatum(partIndexId));
+    if(!HeapTupleIsValid(tuple)) {
+        if (missing_ok)
+            return InvalidOid;
+        ereport(ERROR, (errcode(ERRCODE_CACHE_LOOKUP_FAILED), errmsg("cache lookup failed for partition index %u", partIndexId)));
+    }
+    indexForm = (Form_pg_partition)GETSTRUCT(tuple);
+    
+    result = indexForm->indextblid;
+    ReleaseSysCache(tuple);
+    return result;
+}
+
+/*
+ * PartIdGetParentId: given an partition OID, get the OID of the
+ * parent. Uses the system cache.
+ */
+Oid PartIdGetParentId(Oid partIndexId, bool missing_ok)
+{
+    HeapTuple tuple;
+    Form_pg_partition indexForm;
+    Oid result;
+
+    tuple = SearchSysCache1(PARTRELID, ObjectIdGetDatum(partIndexId));
+    if(!HeapTupleIsValid(tuple)) {
+        if (missing_ok)
+            return InvalidOid;
+        ereport(ERROR, (errcode(ERRCODE_CACHE_LOOKUP_FAILED), errmsg("cache lookup failed for partition %u", partIndexId)));
+    }
+    indexForm = (Form_pg_partition)GETSTRUCT(tuple);
+    
+    result = indexForm->parentid;
+    ReleaseSysCache(tuple);
+    return result;
+}
 /*
  * @@GaussDB@@
  * Target		: data partition
@@ -5028,6 +5739,49 @@ bool reindexPartition(Oid relid, Oid partOid, int flags, int reindexType)
     return result;
 }
 
+/*
+ * Use PartitionOid and indexId look for indexPartitionOid
+ */
+Oid heapPartitionIdGetindexPartitionId(Oid indexId, Oid partOid) {
+    Relation partRel = NULL;
+    SysScanDesc partScan;
+    HeapTuple partTuple;
+    Form_pg_partition partForm;
+    ScanKeyData partKey;
+    Oid indexPartOid = InvalidOid;
+
+     /*
+     * Find the tuple in pg_partition whose 'indextblid' is partOid
+     * and 'parentid' is indexId with systable scan.
+     */
+    partRel = heap_open(PartitionRelationId, AccessShareLock);
+
+    ScanKeyInit(&partKey, Anum_pg_partition_indextblid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(partOid));
+
+    partScan = systable_beginscan(partRel, PartitionIndexTableIdIndexId, true, NULL, 1, &partKey);
+
+    while ((partTuple = systable_getnext(partScan)) != NULL) {
+        partForm = (Form_pg_partition)GETSTRUCT(partTuple);
+
+        if (partForm->parentid == indexId) {
+            indexPartOid = HeapTupleGetOid(partTuple);
+            break;
+        }
+    }
+
+    /* End scan and close pg_partition */
+    systable_endscan(partScan);
+    heap_close(partRel, AccessShareLock);
+
+    if (!OidIsValid(indexPartOid)) {
+        ereport(ERROR,
+            (errcode(ERRCODE_CACHE_LOOKUP_FAILED),
+                errmsg("cache lookup failed for partitioned index %u", indexId)));
+    }
+
+    return indexPartOid;
+}
+
 /*
  * reindexPartIndex - This routine is used to recreate a single index partition
  */
@@ -5079,11 +5833,6 @@ static void reindexPartIndex(Oid indexId, Oid partOid, bool skip_constraint_chec
 
     PG_TRY();
     {
-        Relation partRel = NULL;
-        SysScanDesc partScan;
-        HeapTuple partTuple;
-        Form_pg_partition partForm;
-        ScanKeyData partKey;
         Oid indexPartOid = InvalidOid;
 
         /* Suppress use of the target index while rebuilding it */
@@ -5103,34 +5852,8 @@ static void reindexPartIndex(Oid indexId, Oid partOid, bool skip_constraint_chec
         }
 
         // step 1: rebuild index partition
-        /*
-         * Find the tuple in pg_partition whose 'indextblid' is partOid
-         * and 'parentid' is indexId with systable scan.
-         */
-        partRel = heap_open(PartitionRelationId, AccessShareLock);
-
-        ScanKeyInit(&partKey, Anum_pg_partition_indextblid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(partOid));
-
-        partScan = systable_beginscan(partRel, PartitionIndexTableIdIndexId, true, NULL, 1, &partKey);
-
-        while ((partTuple = systable_getnext(partScan)) != NULL) {
-            partForm = (Form_pg_partition)GETSTRUCT(partTuple);
-
-            if (partForm->parentid == indexId) {
-                indexPartOid = HeapTupleGetOid(partTuple);
-                break;
-            }
-        }
-
-        /* End scan and close pg_partition */
-        systable_endscan(partScan);
-        heap_close(partRel, AccessShareLock);
-
-        if (!OidIsValid(indexPartOid)) {
-            ereport(ERROR,
-                (errcode(ERRCODE_CACHE_LOOKUP_FAILED),
-                    errmsg("cache lookup failed for partitioned index %u", indexId)));
-        }
+        /* Use partOid and indexOid look for indexPartOid */
+        indexPartOid = heapPartitionIdGetindexPartitionId(indexId, partOid);
 
         /* Now, we have get the index partition oid and open it. */
         heapPart = partitionOpen(heapRelation, partOid, ShareLock);

src/common/backend/catalog/pg_depend.cpp

@@ -396,6 +396,84 @@ long changeDependencyFor(Oid classId, Oid objectId, Oid refClassId, Oid oldRefOb
     return count;
 }
 
+/*
+ * Adjust all dependency records to point to a different object of the same type
+ *
+ * refClassId/oldRefObjectId specify the old referenced object.
+ * newRefObjectId is the new referenced object (must be of class refClassId).
+ * 
+ * Returns the number of records updated.
+ */
+long changeDependenciesOn(Oid refClassId, Oid oldRefObjectId, Oid newRefObjectId)
+{
+    long count = 0;
+    Relation depRel = NULL;
+    ScanKeyData key[2];
+    SysScanDesc scan = NULL;
+    HeapTuple tup = NULL;
+    ObjectAddress objAddr;
+    bool newIsPinned = false;
+
+    depRel = heap_open(DependRelationId, RowExclusiveLock);
+    /*
+     * If oldRefObjectId is pinned, there won't be any dependency entries on
+     * it --- we can't cope in that case. (This isn't really worth expending
+     * code to fix, in current usage; it just means you can't rename stuff out
+     * of pg_catalog, which would likely be a bad move anyway.)
+     */
+    objAddr.classId = refClassId;
+    objAddr.objectId = oldRefObjectId;
+    objAddr.objectSubId = 0;
+
+    if (isObjectPinned(&objAddr, depRel))
+        ereport (ERROR, 
+            (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+                errmsg("cannot remove dependency on %s because it is a system object",
+                    getObjectDescription(&objAddr))));
+
+    /*
+     * We can handle adding a dependency on something pinned, though, since
+     * that just means deleting the dependency entry.
+     */
+    objAddr.objectId = newRefObjectId;
+
+    newIsPinned = isObjectPinned(&objAddr, depRel);
+
+    /* Now search for dependency records */
+    ScanKeyInit(&key[0], Anum_pg_depend_refclassid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(refClassId));
+    ScanKeyInit(&key[1], Anum_pg_depend_refobjid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(oldRefObjectId));
+
+    scan = systable_beginscan(depRel, DependReferenceIndexId, true, NULL, 2, key);
+
+    while (HeapTupleIsValid(tup = systable_getnext(scan)))
+    {
+        Form_pg_depend depform = (Form_pg_depend) GETSTRUCT(tup);
+
+        if(newIsPinned)
+            simple_heap_delete(depRel, &tup->t_self);
+        else {
+            /* make a modifiable copy */
+            tup = heap_copytuple(tup);
+            depform = (Form_pg_depend) GETSTRUCT(tup);
+
+            depform->refobjid = newRefObjectId;
+
+            simple_heap_update(depRel, &tup->t_self, tup);
+            CatalogUpdateIndexes(depRel, tup);
+
+            heap_freetuple_ext(tup);
+        }
+
+        count++;
+    }
+
+    systable_endscan(scan);
+
+    heap_close(depRel, RowExclusiveLock);
+
+    return count;
+}
+
 /*
  * isObjectPinned()
  *
@@ -681,3 +759,46 @@ Oid get_index_constraint(Oid indexId)
 
     return constraintId;
 }
+
+/*
+ * get_index_ref_constraints
+ *     Given the OID of an index, return the OID of all foreign key
+ *     constraints which reference the index.
+ */
+List* get_index_ref_constraints(Oid indexId)
+{
+    List* result = NULL;
+    Relation depRel = NULL;
+    ScanKeyData key[3];
+    SysScanDesc scan = NULL;
+    HeapTuple tup = NULL;
+
+    /* search the dependency table for the index */
+    depRel = heap_open(DependRelationId,AccessShareLock);
+
+    ScanKeyInit(&key[0], Anum_pg_depend_refclassid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(RelationRelationId));
+    ScanKeyInit(&key[1], Anum_pg_depend_refobjid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(indexId));
+    ScanKeyInit(&key[2], Anum_pg_depend_refobjsubid, BTEqualStrategyNumber, F_INT4EQ, Int32GetDatum(0));
+
+    scan = systable_beginscan(depRel, DependReferenceIndexId, true, NULL, 3, key);
+
+    while (HeapTupleIsValid(tup = systable_getnext(scan)))
+    {
+        Form_pg_depend deprec = (Form_pg_depend) GETSTRUCT(tup);
+
+        /*
+         * We assume any normal dependency from a constraint must be what we
+         * are looking for.
+         */
+        if (deprec->classid == ConstraintRelationId && deprec->objsubid == 0 &&
+            deprec->deptype == DEPENDENCY_NORMAL)
+        {
+            result = lappend_oid(result, deprec->objid);
+        }
+    }
+
+    systable_endscan(scan);
+    heap_close(depRel, AccessShareLock);
+
+    return result;
+}

src/common/backend/nodes/copyfuncs.cpp

@@ -5816,6 +5816,8 @@ static ReindexStmt* _copyReindexStmt(const ReindexStmt* from)
     COPY_SCALAR_FIELD(do_user);
     COPY_SCALAR_FIELD(memUsage.work_mem);
     COPY_SCALAR_FIELD(memUsage.max_mem);
+    /*use for reindex concurrently*/
+    COPY_SCALAR_FIELD(concurrent);
 
     return newnode;
 }

src/common/backend/nodes/equalfuncs.cpp

@@ -2115,6 +2115,8 @@ static bool _equalReindexStmt(const ReindexStmt* a, const ReindexStmt* b)
     COMPARE_STRING_FIELD(name);
     COMPARE_SCALAR_FIELD(do_system);
     COMPARE_SCALAR_FIELD(do_user);
+    /*use for reindex concurerntly*/
+    COMPARE_SCALAR_FIELD(concurrent);
 
     return true;
 }

src/common/backend/parser/gram.y

@@ -12174,22 +12174,23 @@ opt_if_exists: IF_P EXISTS						{ $$ = TRUE; }
  *
  *		QUERY:
  *
- *		REINDEX type <name> [FORCE]
+ *		REINDEX type [CONCURRENTLY] <name> [FORCE]
  *
  * FORCE no longer does anything, but we accept it for backwards compatibility
  *****************************************************************************/
 
 ReindexStmt:
-			REINDEX reindex_type qualified_name opt_force
+			REINDEX reindex_type opt_concurrently qualified_name opt_force
 				{
 					ReindexStmt *n = makeNode(ReindexStmt);
 					n->kind = $2;
-					n->relation = $3;
+					n->concurrent = $3;
+					n->relation = $4;
 					n->name = NULL;
 					$$ = (Node *)n;
 				}
 			|
-			REINDEX reindex_type qualified_name PARTITION ColId opt_force
+			REINDEX reindex_type opt_concurrently qualified_name PARTITION ColId opt_force
 				{
 					ReindexStmt *n = makeNode(ReindexStmt);
 					if ($2 == OBJECT_INDEX)
@@ -12198,25 +12199,28 @@ ReindexStmt:
 						n->kind  = OBJECT_TABLE_PARTITION;
 					else
 						n->kind  = OBJECT_INTERNAL_PARTITION;
-					n->relation = $3;
-					n->name = $5;
+					n->concurrent = $3;
+					n->relation = $4;
+					n->name = $6;
 					$$ = (Node *)n;
 				}
-			| REINDEX SYSTEM_P name opt_force
+			| REINDEX SYSTEM_P opt_concurrently name opt_force
 				{
 					ReindexStmt *n = makeNode(ReindexStmt);
 					n->kind = OBJECT_DATABASE;
-					n->name = $3;
+					n->concurrent = $3;
+					n->name = $4;
 					n->relation = NULL;
 					n->do_system = true;
 					n->do_user = false;
 					$$ = (Node *)n;
 				}
-			| REINDEX DATABASE name opt_force
+			| REINDEX DATABASE opt_concurrently name opt_force
 				{
 					ReindexStmt *n = makeNode(ReindexStmt);
 					n->kind = OBJECT_DATABASE;
-					n->name = $3;
+					n->concurrent = $3;
+					n->name = $4;
 					n->relation = NULL;
 					n->do_system = true;
 					n->do_user = true;

src/gausskernel/optimizer/commands/tablecmds.cpp

@@ -3578,10 +3578,12 @@ static void RangeVarCallbackForDropRelation(
     char relkind;
     Form_pg_class classform;
     LOCKMODE heap_lockmode;
+    bool invalid_system_index;         /*use for reindex concurrent*/
 
     state = (struct DropRelationCallbackState*)arg;
     relkind = state->relkind;
     heap_lockmode = state->concurrent ? ShareUpdateExclusiveLock : AccessExclusiveLock;
+    invalid_system_index = false;
 
     if (target_is_partition)
         heap_lockmode = AccessShareLock;
@@ -3616,10 +3618,37 @@ static void RangeVarCallbackForDropRelation(
         DropErrorMsgWrongType(rel->relname, classform->relkind, relkind);
     }
 
+    /*
+    * Check the case of a system index that might have been invalidated by a
+    * failed concurrent process and allow its drop. For the time being, this
+    * only concerns indexes of toast relations that became invalid during a
+    * REINDEX CONCURRENTLY process.
+    */
+    if(IsSystemClass(classform)&&relkind == RELKIND_INDEX) {
+        HeapTuple locTuple;
+        Form_pg_index indexform;
+        bool indisvalid;
+
+        locTuple = SearchSysCache1(INDEXRELID,ObjectIdGetDatum(relOid));
+        if(!HeapTupleIsValid(locTuple)) {
+            ReleaseSysCache(tuple);
+            return;
+        }
+
+        indexform = (Form_pg_index) GETSTRUCT(locTuple);
+        indisvalid = indexform->indisvalid;
+        ReleaseSysCache(locTuple);
+
+        /*Mark object as being an invaild index of system catalogs*/
+        if(!indisvalid)
+            invalid_system_index = true;
+    }
+
+
     /* Permission Check */
     DropRelationPermissionCheck(relkind, relOid, classform->relnamespace, rel->relname);
 
-    if (!CheckClassFormPermission(classform)) {
+    if (!invalid_system_index && !CheckClassFormPermission(classform)) {
         ereport(ERROR,
             (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
                 errmsg("permission denied: \"%s\" is a system catalog", rel->relname)));

src/gausskernel/process/tcop/utility.cpp

@@ -2201,16 +2201,16 @@ void ReindexCommand(ReindexStmt* stmt, bool is_top_level)
     switch (stmt->kind) {
         case OBJECT_INDEX:
         case OBJECT_INDEX_PARTITION:
-            ReindexIndex(stmt->relation, (const char*)stmt->name, &stmt->memUsage);
+            ReindexIndex(stmt->relation, (const char*)stmt->name, &stmt->memUsage,stmt->concurrent);
             break;
         case OBJECT_TABLE:
         case OBJECT_MATVIEW:
         case OBJECT_TABLE_PARTITION:
-            ReindexTable(stmt->relation, (const char*)stmt->name, &stmt->memUsage);
+            ReindexTable(stmt->relation, (const char*)stmt->name, &stmt->memUsage,stmt->concurrent);
             break;
         case OBJECT_INTERNAL:
         case OBJECT_INTERNAL_PARTITION:
-            ReindexInternal(stmt->relation, (const char*)stmt->name);
+            ReindexInternal(stmt->relation, (const char*)stmt->name,stmt->concurrent);
             break;
         case OBJECT_DATABASE:
 
@@ -2221,7 +2221,7 @@ void ReindexCommand(ReindexStmt* stmt, bool is_top_level)
              * intended effect!
              */
             PreventTransactionChain(is_top_level, "REINDEX DATABASE");
-            ReindexDatabase(stmt->name, stmt->do_system, stmt->do_user, &stmt->memUsage);
+            ReindexDatabase(stmt->name, stmt->do_system, stmt->do_user, &stmt->memUsage,stmt->concurrent);
             break;
         default: {
             ereport(ERROR,
@@ -6581,6 +6581,11 @@ void standard_ProcessUtility(Node* parse_tree, const char* query_string, ParamLi
             ReindexStmt* stmt = (ReindexStmt*)parse_tree;
             RemoteQueryExecType exec_type;
             bool is_temp = false;
+
+            /* use for reindex concurrent */
+            if(stmt->concurrent)
+                PreventTransactionChain(is_top_level,"REINDEX CONCURRENTLY");
+                
             pgstat_set_io_state(IOSTATE_WRITE);
 #ifdef PGXC
             if (IS_PGXC_COORDINATOR) {

src/include/catalog/dependency.h

@@ -213,6 +213,7 @@ typedef enum ObjectClass {
 #define PERFORM_DELETION_INVALID            0x0000
 #define PERFORM_DELETION_INTERNAL			0x0001
 #define PERFORM_DELETION_CONCURRENTLY		0x0002
+#define PERFORM_DELETION_CONCURRENTLY_LOCK  0x0020    /* normal drop with concurrent lock mode */
 
 /* ObjectAddressExtra flag bits */
 #define DEPFLAG_ORIGINAL 0x0001  /* an original deletion target */
@@ -294,6 +295,9 @@ extern long changeDependencyFor(Oid classId,
                                 Oid oldRefObjectId,
                                 Oid newRefObjectId);
 
+/*use for reindex concurrently*/
+extern long changeDependenciesOn(Oid refClassId,Oid oldRefObjectId,Oid newRefObjectId);
+
 extern Oid	getExtensionOfObject(Oid classId, Oid objectId);
 
 extern bool sequenceIsOwned(Oid seqId, Oid *tableId, int32 *colId);
@@ -306,6 +310,9 @@ extern Oid	get_constraint_index(Oid constraintId);
 
 extern Oid	get_index_constraint(Oid indexId);
 
+/* use for reindex concurrently */
+extern List *get_index_ref_constraints(Oid indexId);
+
 /* in pg_shdepend.c */
 extern void recordSharedDependencyOn(ObjectAddress *depender,
                                      ObjectAddress *referenced,

src/include/catalog/index.h

@@ -125,12 +125,36 @@ extern Oid index_create(Relation heapRelation, const char *indexRelationName, Oi
                         IndexCreateExtraArgs *extra, bool useLowLockLevel = false,
                         int8 relindexsplit = 0);
 
+/* ues for reindex concurrently*/
+extern Oid index_concurrently_create_copy(Relation heapRelation, Oid oldIndexId, const char *newName);
+
+/* use for reindex concurrently*/
+extern void index_concurrently_build(Oid heapRelationId, Oid indexRelationId, bool isPrimary, AdaptMem* memInfo = NULL, bool dbWide = false);
+
+/* use for reindex concurrently*/
+extern void index_concurrently_swap(Oid newIndexId, Oid oldIndexId, const char *oldName);
+
+/* use for reindex concurrently*/
+extern void index_concurrently_set_dead(Oid heapId, Oid indexId);
+
+/* use for reindex concurrently partition */
+extern Oid index_concurrently_part_create_copy(Oid oldIndexPartId, const char *newName);
+
+/* use for reindex concurrently partition */
+extern void index_concurrently_part_build(Oid heapRelationId, Oid heapPartitionId, Oid indexRelationId, Oid IndexPartitionId, AdaptMem* memInfo = NULL, bool dbWide = false);
+
+/* use for reindex concurrently partition */
+extern void index_concurrently_part_swap(Relation indexRelation, Oid newIndexPartId, Oid oldIndexPartId, const char *oldName);
+
+
+
 extern void index_constraint_create(Relation heapRelation, Oid indexRelationId, IndexInfo *indexInfo,
                                     const char *constraintName, char constraintType, bool deferrable,
                                     bool initdeferred, bool mark_as_primary, bool update_pgindex,
                                     bool remove_old_dependencies, bool allow_system_table_mods);
 
-extern void index_drop(Oid indexId, bool concurrent);
+/* change input: add concurrent_lock_mode */
+extern void index_drop(Oid indexId, bool concurrent, bool concurrent_lock_mode = false);
 
 extern IndexInfo *BuildIndexInfo(Relation index);
 extern IndexInfo *BuildDummyIndexInfo(Relation index);
@@ -173,7 +197,7 @@ extern double IndexBuildVectorBatchScan(Relation heapRelation, Relation indexRel
                                         void *transferFuncs);
 
 
-extern void validate_index(Oid heapId, Oid indexId, Snapshot snapshot);
+extern void validate_index(Oid heapId, Oid indexId, Snapshot snapshot, bool isPart = false);
 extern void validate_index_heapscan(
     Relation heapRelation, Relation indexRelation, IndexInfo* indexInfo, Snapshot snapshot, v_i_state* state);
 
@@ -201,6 +225,9 @@ extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 extern Oid IndexGetRelation(Oid indexId, bool missing_ok);
 
+extern Oid PartIndexGetPartition(Oid partIndexId, bool missing_ok);
+extern Oid PartIdGetParentId(Oid partIndexId, bool missing_ok);
+
 typedef struct
 {
     Oid  existingPSortOid;
@@ -232,6 +259,7 @@ extern void PartitionNameCallbackForIndexPartition(Oid partitionedRelationOid,
                                                    LOCKMODE callbackobj_lockMode);
 extern void reindex_partIndex(Relation heapRel,  Partition heapPart, Relation indexRel , Partition indexPart);
 extern bool reindexPartition(Oid relid, Oid partOid, int flags, int reindexType);
+extern Oid heapPartitionIdGetindexPartitionId(Oid indexId, Oid partOid);
 extern void AddGPIForPartition(Oid partTableOid, Oid partOid);
 void AddCBIForPartition(Relation partTableRel, Relation tempTableRel, const List* indexRelList, 
     const List* indexDestOidList);

src/include/commands/defrem.h

@@ -23,11 +23,14 @@ extern void RemoveObjects(DropStmt* stmt, bool missing_ok, bool is_securityadmin
 /* commands/indexcmds.c */
 extern Oid DefineIndex(Oid relationId, IndexStmt* stmt, Oid indexRelationId, bool is_alter_table, bool check_rights,
     bool skip_build, bool quiet);
-extern void ReindexIndex(RangeVar* indexRelation, const char* partition_name, AdaptMem* mem_info);
-extern void ReindexTable(RangeVar* relation, const char* partition_name, AdaptMem* mem_info);
-extern void ReindexInternal(RangeVar* relation, const char* partition_name);
 
-extern void ReindexDatabase(const char* databaseName, bool do_system, bool do_user, AdaptMem* mem_info);
+/*add input for reindex concurrently*/    
+extern void ReindexIndex(RangeVar* indexRelation, const char* partition_name, AdaptMem* mem_info, bool concurrent);
+extern void ReindexTable(RangeVar* relation, const char* partition_name, AdaptMem* mem_info, bool concurrent);
+extern void ReindexInternal(RangeVar* relation, const char* partition_name, bool concurrent);
+
+/*add input for reindex concurrently */
+extern void ReindexDatabase(const char* databaseName, bool do_system, bool do_user, AdaptMem* mem_info, bool concurrent);
 extern char* makeObjectName(const char* name1, const char* name2, const char* label, bool reverseTruncate = false);
 extern char* ChooseRelationName(
     const char* name1, const char* name2, const char* label, size_t labelLength, Oid namespaceid,

src/include/nodes/parsenodes_common.h

@@ -765,6 +765,7 @@ typedef struct ReindexStmt {
     bool do_system;     /* include system tables in database case */
     bool do_user;       /* include user tables in database case */
     AdaptMem memUsage;  /* adaptive memory assigned for the stmt */
+    bool concurrent;    /* reindex concurrently */
 } ReindexStmt;
 
 typedef struct Position {

src/test/regress/expected/reindex_concurrently.out

@@ -0,0 +1,87 @@
+--
+-- REINDEX CONCURRENTLY
+--
+CREATE TABLE concur_reindex_tab (c1 int);
+-- REINDEX
+REINDEX TABLE concur_reindex_tab; -- notice
+NOTICE:  table "concur_reindex_tab" has no indexes
+REINDEX TABLE CONCURRENTLY concur_reindex_tab; -- notice
+NOTICE:  table "concur_reindex_tab" has no indexes
+ALTER TABLE concur_reindex_tab ADD COLUMN c2 text; -- add toast index
+-- Normal index with integer column
+CREATE UNIQUE INDEX concur_reindex_ind1 ON concur_reindex_tab(c1);
+-- Normal index with text column
+CREATE INDEX concur_reindex_ind2 ON concur_reindex_tab(c2);
+-- UNION INDEX index with expression
+CREATE UNIQUE INDEX concur_reindex_ind3 ON concur_reindex_tab(abs(c1));
+-- Duplicates column names error
+CREATE INDEX concur_reindex_ind4 ON concur_reindex_tab(c1, c1, c2);
+ERROR:  duplicate column name
+-- Create table for check on foreign key dependence switch with indexes swapped
+ALTER TABLE concur_reindex_tab ADD PRIMARY KEY USING INDEX concur_reindex_ind1;
+CREATE TABLE concur_reindex_tab2 (c1 int REFERENCES concur_reindex_tab);
+INSERT INTO concur_reindex_tab VALUES (1, 'a');
+INSERT INTO concur_reindex_tab VALUES (2, 'a');
+-- Check materialized views
+CREATE MATERIALIZED VIEW concur_reindex_matview AS SELECT * FROM concur_reindex_tab;
+REINDEX INDEX CONCURRENTLY concur_reindex_ind1;
+REINDEX TABLE CONCURRENTLY concur_reindex_tab;
+REINDEX TABLE CONCURRENTLY concur_reindex_matview;
+-- Check views 
+CREATE VIEW concur_reindex_view AS SELECT * FROM concur_reindex_tab;
+REINDEX TABLE CONCURRENTLY concur_reindex_view; -- Error
+ERROR:  "concur_reindex_view" is not a table or materialized view
+-- Check that comments are preserved
+CREATE TABLE testcomment (i int);
+CREATE INDEX testcomment_idx1 ON testcomment(i);
+COMMENT ON INDEX testcomment_idx1 IS 'test comment';
+SELECT obj_description('testcomment_idx1'::regclass, 'pg_class');
+ obj_description 
+-----------------
+ test comment
+(1 row)
+
+REINDEX TABLE testcomment;
+SELECT obj_description('testcomment_idx1'::regclass, 'pg_class');
+ obj_description 
+-----------------
+ test comment
+(1 row)
+
+REINDEX TABLE CONCURRENTLY testcomment;
+SELECT obj_description('testcomment_idx1'::regclass, 'pg_class');
+ obj_description 
+-----------------
+ test comment
+(1 row)
+
+DROP TABLE testcomment;
+-- Check error
+-- Cannot run inside a transaction block
+BEGIN;
+REINDEX TABLE CONCURRENTLY concur_reindex_tab;
+ERROR:  REINDEX CONCURRENTLY cannot run inside a transaction block
+COMMIT;
+REINDEX TABLE CONCURRENTLY pg_database; -- no shared relation
+ERROR:  concurrent index creation on system catalog tables is not supported
+REINDEX TABLE CONCURRENTLY pg_class; -- no catalog relations
+ERROR:  concurrent index creation on system catalog tables is not supported
+REINDEX SYSTEM CONCURRENTLY postgres; -- not allowed for SYSTEM
+ERROR:  can only reindex the currently open database
+-- Check the relation status, there should not be invalid indexe
+\d concur_reindex_tab
+Table "public.concur_reindex_tab"
+ Column |  Type   | Modifiers 
+--------+---------+-----------
+ c1     | integer | not null
+ c2     | text    | 
+Indexes:
+    "concur_reindex_ind1" PRIMARY KEY, btree (c1) TABLESPACE pg_default
+    "concur_reindex_ind3" UNIQUE, btree (abs(c1)) TABLESPACE pg_default
+    "concur_reindex_ind2" btree (c2) TABLESPACE pg_default
+Referenced by:
+    TABLE "concur_reindex_tab2" CONSTRAINT "concur_reindex_tab2_c1_fkey" FOREIGN KEY (c1) REFERENCES concur_reindex_tab(c1)
+
+DROP VIEW concur_reindex_view;
+DROP MATERIALIZED VIEW concur_reindex_matview;
+DROP TABLE concur_reindex_tab, concur_reindex_tab2;

src/test/regress/expected/reindex_concurrently_parallel.out

@@ -0,0 +1,59 @@
+--
+-- REINDEX CONCURRENTLY PARALLEL
+--
+CREATE TABLE reind_con_tab(id serial primary key, data text);
+NOTICE:  CREATE TABLE will create implicit sequence "reind_con_tab_id_seq" for serial column "reind_con_tab.id"
+NOTICE:  CREATE TABLE / PRIMARY KEY will create implicit index "reind_con_tab_pkey" for table "reind_con_tab"
+INSERT INTO reind_con_tab(data) VALUES ('aa');
+INSERT INTO reind_con_tab(data) VALUES ('aaa');
+INSERT INTO reind_con_tab(data) VALUES ('aaaa');
+INSERT INTO reind_con_tab(data) VALUES ('aaaaa');
+\d reind_con_tab;
+                         Table "public.reind_con_tab"
+ Column |  Type   |                         Modifiers                          
+--------+---------+------------------------------------------------------------
+ id     | integer | not null default nextval('reind_con_tab_id_seq'::regclass)
+ data   | text    | 
+Indexes:
+    "reind_con_tab_pkey" PRIMARY KEY, btree (id) TABLESPACE pg_default
+
+\parallel on
+REINDEX TABLE CONCURRENTLY reind_con_tab;
+SELECT data FROM reind_con_tab WHERE id =3;
+\parallel off
+ data 
+------
+ aaaa
+(1 row)
+
+\parallel on
+REINDEX TABLE CONCURRENTLY reind_con_tab;
+UPDATE reind_con_tab SET data = 'bbbb' WHERE id = 3;
+\parallel off
+\parallel on
+REINDEX TABLE CONCURRENTLY reind_con_tab;
+INSERT INTO reind_con_tab(data) VALUES('cccc');
+\parallel off
+\parallel on
+REINDEX TABLE CONCURRENTLY reind_con_tab;
+DELETE FROM reind_con_tab WHERE data = 'aaa';
+\parallel off
+SELECT * FROM reind_con_tab;
+ id | data  
+----+-------
+  1 | aa
+  4 | aaaaa
+  3 | bbbb
+  5 | cccc
+(4 rows)
+
+\d reind_con_tab;
+                         Table "public.reind_con_tab"
+ Column |  Type   |                         Modifiers                          
+--------+---------+------------------------------------------------------------
+ id     | integer | not null default nextval('reind_con_tab_id_seq'::regclass)
+ data   | text    | 
+Indexes:
+    "reind_con_tab_pkey" PRIMARY KEY, btree (id) TABLESPACE pg_default
+
+DROP TABLE reind_con_tab;

src/test/regress/expected/reindex_concurrently_partition.out

@@ -0,0 +1,55 @@
+--
+-- REINDEX CONCURRENTLY PARTITION
+--
+drop table if exists t1;
+NOTICE:  table "t1" does not exist, skipping
+create table t1(
+ c_id  varchar,
+ c_w_id  integer,
+ c_date     date
+ )
+partition by range (c_date,c_w_id)
+(
+  PARTITION t1_1 values less than ('20170331',5),
+  PARTITION t1_2 values less than ('20170731',450),
+  PARTITION t1_3 values less than ('20170930',1062),
+  PARTITION t1_4 values less than ('20171231',1765),
+  PARTITION t1_5 values less than ('20180331',2024),
+  PARTITION t1_6 values less than ('20180731',2384),
+  PARTITION t1_7 values less than ('20180930',2786),
+  PARTITION t1_8 values less than (maxvalue,maxvalue)
+);
+insert into t1 values('gauss1',4,'20170301');
+insert into t1 values('gauss2',400,'20170625');
+insert into t1 values('gauss3',480,'20170920');
+insert into t1 values('gauss4',1065,'20170920');
+insert into t1 values('gauss5',1800,'20170920');
+insert into t1 values('gauss6',2030,'20170920');
+insert into t1 values('gauss7',2385,'20170920');
+insert into t1 values('gauss8',2789,'20191020');
+insert into t1 values('gauss9',2789,'20171020');
+create index idx_t1 on t1 using btree(c_id) LOCAL;
+create index idx2_t1 on t1 using btree(c_id) LOCAL (
+								PARTITION t1_1_index,
+								PARTITION t1_2_index,
+								PARTITION t1_3_index,
+								PARTITION t1_4_index,
+								PARTITION t1_5_index,
+								PARTITION t1_6_index,
+								PARTITION t1_7_index,
+								PARTITION t1_8_index
+);
+reindex index CONCURRENTLY idx_t1;
+reindex index CONCURRENTLY idx2_t1 partition t1_1_index;
+reindex table CONCURRENTLY t1;
+reindex table CONCURRENTLY t1 partition t1_1;
+drop index idx_t1;
+drop index idx2_t1;
+create index idx_t1 on t1 using btree(c_id);
+reindex index idx_t1;
+reindex index CONCURRENTLY idx_t1; --ERROR, can't reindex concurrently global index partition
+ERROR:  cannot reindex concurrently global partition index " public.idx_t1"
+reindex table t1;
+reindex table CONCURRENTLY t1; --WARNING, can't reindex concurrently global index partition
+WARNING:  cannot reindex concurrently global partition index " public.idx_t1", skipping
+drop table t1;

src/test/regress/expected/reindex_concurrently_partition_parallel.out

@@ -0,0 +1,51 @@
+--
+-- REINDEX CONCURRENTLY PARTITION PARALLEL
+--
+drop table if exists t2;
+NOTICE:  table "t2" does not exist, skipping
+CREATE TABLE t2 (id int, data text) partition by range(id)(partition p1 values less than(100), partition p2 values less than(200), partition p3 values less than(MAXVALUE));
+insert into t2 select generate_series(1,500),generate_series(1,500);
+create index ind_id on t2(id) LOCAL;
+select * from t2 where id = 4;
+ id | data 
+----+------
+  4 | 4
+(1 row)
+
+\parallel on
+REINDEX index CONCURRENTLY ind_id;
+select * from t2 where id = 3;
+\parallel off
+ id | data 
+----+------
+  3 | 3
+(1 row)
+
+\parallel on
+REINDEX index CONCURRENTLY ind_id;
+delete from t2 where id = 4;
+\parallel off
+\parallel on
+REINDEX index CONCURRENTLY ind_id;
+insert into t2 values (4,3);
+\parallel off
+\parallel on
+REINDEX index CONCURRENTLY ind_id;
+update t2 set data = 4 where id = 4;
+\parallel off
+\parallel on
+REINDEX index CONCURRENTLY ind_id;
+select * from t2 where id = 4;
+\parallel off
+ id | data 
+----+------
+  4 | 4
+(1 row)
+
+select * from t2 where id = 4;
+ id | data 
+----+------
+  4 | 4
+(1 row)
+
+drop table t2;

src/test/regress/parallel_schedule0

@@ -831,8 +831,15 @@ test: comment_proc
 test: hw_package
 test: procedure_privilege_test
 test: cast_privileges_test
+
+test: reindex_concurrently
+test: reindex_concurrently_parallel
+test: reindex_concurrently_partition
+test: reindex_concurrently_partition_parallel
+
 #test: hw_dbms_sql1
 test: hw_cipher_sm4
 test: hw_cipher_aes128
 test: sequence_cache_test
-test: pg_buffercache_pages
+test: pg_buffercache_pages
+

src/test/regress/sql/reindex_concurrently.sql

@@ -0,0 +1,54 @@
+--
+-- REINDEX CONCURRENTLY
+--
+CREATE TABLE concur_reindex_tab (c1 int);
+-- REINDEX
+REINDEX TABLE concur_reindex_tab; -- notice
+REINDEX TABLE CONCURRENTLY concur_reindex_tab; -- notice
+ALTER TABLE concur_reindex_tab ADD COLUMN c2 text; -- add toast index
+-- Normal index with integer column
+CREATE UNIQUE INDEX concur_reindex_ind1 ON concur_reindex_tab(c1);
+-- Normal index with text column
+CREATE INDEX concur_reindex_ind2 ON concur_reindex_tab(c2);
+-- UNION INDEX index with expression
+CREATE UNIQUE INDEX concur_reindex_ind3 ON concur_reindex_tab(abs(c1));
+-- Duplicates column names error
+CREATE INDEX concur_reindex_ind4 ON concur_reindex_tab(c1, c1, c2);
+-- Create table for check on foreign key dependence switch with indexes swapped
+ALTER TABLE concur_reindex_tab ADD PRIMARY KEY USING INDEX concur_reindex_ind1;
+CREATE TABLE concur_reindex_tab2 (c1 int REFERENCES concur_reindex_tab);
+INSERT INTO concur_reindex_tab VALUES (1, 'a');
+INSERT INTO concur_reindex_tab VALUES (2, 'a');
+-- Check materialized views
+CREATE MATERIALIZED VIEW concur_reindex_matview AS SELECT * FROM concur_reindex_tab;
+REINDEX INDEX CONCURRENTLY concur_reindex_ind1;
+REINDEX TABLE CONCURRENTLY concur_reindex_tab;
+REINDEX TABLE CONCURRENTLY concur_reindex_matview;
+-- Check views 
+CREATE VIEW concur_reindex_view AS SELECT * FROM concur_reindex_tab;
+REINDEX TABLE CONCURRENTLY concur_reindex_view; -- Error
+-- Check that comments are preserved
+CREATE TABLE testcomment (i int);
+CREATE INDEX testcomment_idx1 ON testcomment(i);
+COMMENT ON INDEX testcomment_idx1 IS 'test comment';
+SELECT obj_description('testcomment_idx1'::regclass, 'pg_class');
+REINDEX TABLE testcomment;
+SELECT obj_description('testcomment_idx1'::regclass, 'pg_class');
+REINDEX TABLE CONCURRENTLY testcomment;
+SELECT obj_description('testcomment_idx1'::regclass, 'pg_class');
+DROP TABLE testcomment;
+
+-- Check error
+-- Cannot run inside a transaction block
+BEGIN;
+REINDEX TABLE CONCURRENTLY concur_reindex_tab;
+COMMIT;
+REINDEX TABLE CONCURRENTLY pg_database; -- no shared relation
+REINDEX TABLE CONCURRENTLY pg_class; -- no catalog relations
+REINDEX SYSTEM CONCURRENTLY postgres; -- not allowed for SYSTEM
+
+-- Check the relation status, there should not be invalid indexe
+\d concur_reindex_tab
+DROP VIEW concur_reindex_view;
+DROP MATERIALIZED VIEW concur_reindex_matview;
+DROP TABLE concur_reindex_tab, concur_reindex_tab2;

src/test/regress/sql/reindex_concurrently_parallel.sql

@@ -0,0 +1,33 @@
+--
+-- REINDEX CONCURRENTLY PARALLEL
+--
+CREATE TABLE reind_con_tab(id serial primary key, data text);
+INSERT INTO reind_con_tab(data) VALUES ('aa');
+INSERT INTO reind_con_tab(data) VALUES ('aaa');
+INSERT INTO reind_con_tab(data) VALUES ('aaaa');
+INSERT INTO reind_con_tab(data) VALUES ('aaaaa');
+\d reind_con_tab;
+
+\parallel on
+REINDEX TABLE CONCURRENTLY reind_con_tab;
+SELECT data FROM reind_con_tab WHERE id =3;
+\parallel off
+
+\parallel on
+REINDEX TABLE CONCURRENTLY reind_con_tab;
+UPDATE reind_con_tab SET data = 'bbbb' WHERE id = 3;
+\parallel off
+
+\parallel on
+REINDEX TABLE CONCURRENTLY reind_con_tab;
+INSERT INTO reind_con_tab(data) VALUES('cccc');
+\parallel off
+
+\parallel on
+REINDEX TABLE CONCURRENTLY reind_con_tab;
+DELETE FROM reind_con_tab WHERE data = 'aaa';
+\parallel off
+
+SELECT * FROM reind_con_tab;
+\d reind_con_tab;
+DROP TABLE reind_con_tab;

src/test/regress/sql/reindex_concurrently_partition.sql

@@ -0,0 +1,58 @@
+--
+-- REINDEX CONCURRENTLY PARTITION
+--
+
+drop table if exists t1;
+create table t1(
+ c_id  varchar,
+ c_w_id  integer,
+ c_date     date
+ )
+partition by range (c_date,c_w_id)
+(
+  PARTITION t1_1 values less than ('20170331',5),
+  PARTITION t1_2 values less than ('20170731',450),
+  PARTITION t1_3 values less than ('20170930',1062),
+  PARTITION t1_4 values less than ('20171231',1765),
+  PARTITION t1_5 values less than ('20180331',2024),
+  PARTITION t1_6 values less than ('20180731',2384),
+  PARTITION t1_7 values less than ('20180930',2786),
+  PARTITION t1_8 values less than (maxvalue,maxvalue)
+);
+
+insert into t1 values('gauss1',4,'20170301');
+insert into t1 values('gauss2',400,'20170625');
+insert into t1 values('gauss3',480,'20170920');
+insert into t1 values('gauss4',1065,'20170920');
+insert into t1 values('gauss5',1800,'20170920');
+insert into t1 values('gauss6',2030,'20170920');
+insert into t1 values('gauss7',2385,'20170920');
+insert into t1 values('gauss8',2789,'20191020');
+insert into t1 values('gauss9',2789,'20171020');
+
+create index idx_t1 on t1 using btree(c_id) LOCAL;
+create index idx2_t1 on t1 using btree(c_id) LOCAL (
+								PARTITION t1_1_index,
+								PARTITION t1_2_index,
+								PARTITION t1_3_index,
+								PARTITION t1_4_index,
+								PARTITION t1_5_index,
+								PARTITION t1_6_index,
+								PARTITION t1_7_index,
+								PARTITION t1_8_index
+);
+reindex index CONCURRENTLY idx_t1;
+reindex index CONCURRENTLY idx2_t1 partition t1_1_index;
+reindex table CONCURRENTLY t1;
+reindex table CONCURRENTLY t1 partition t1_1;
+
+drop index idx_t1;
+drop index idx2_t1;
+
+create index idx_t1 on t1 using btree(c_id);
+reindex index idx_t1;
+reindex index CONCURRENTLY idx_t1; --ERROR, can't reindex concurrently global index partition
+reindex table t1;
+reindex table CONCURRENTLY t1; --WARNING, can't reindex concurrently global index partition
+
+drop table t1;

src/test/regress/sql/reindex_concurrently_partition_parallel.sql

@@ -0,0 +1,38 @@
+--
+-- REINDEX CONCURRENTLY PARTITION PARALLEL
+--
+drop table if exists t2;
+
+CREATE TABLE t2 (id int, data text) partition by range(id)(partition p1 values less than(100), partition p2 values less than(200), partition p3 values less than(MAXVALUE));
+insert into t2 select generate_series(1,500),generate_series(1,500);
+create index ind_id on t2(id) LOCAL;
+
+select * from t2 where id = 4;
+
+\parallel on
+REINDEX index CONCURRENTLY ind_id;
+select * from t2 where id = 3;
+\parallel off
+
+\parallel on
+REINDEX index CONCURRENTLY ind_id;
+delete from t2 where id = 4;
+\parallel off
+
+\parallel on
+REINDEX index CONCURRENTLY ind_id;
+insert into t2 values (4,3);
+\parallel off
+
+\parallel on
+REINDEX index CONCURRENTLY ind_id;
+update t2 set data = 4 where id = 4;
+\parallel off
+
+\parallel on
+REINDEX index CONCURRENTLY ind_id;
+select * from t2 where id = 4;
+\parallel off
+
+select * from t2 where id = 4;
+drop table t2;