Fix drop index trying to drop coordinator local indexes on metadata worker nodes

src/backend/distributed/commands/index.c

@@ -24,6 +24,7 @@
 #include "distributed/commands.h"
 #include "distributed/commands/utility_hook.h"
 #include "distributed/deparse_shard_query.h"
+#include "distributed/deparser.h"
 #include "distributed/distributed_planner.h"
 #include "distributed/listutils.h"
 #include "distributed/local_executor.h"
@@ -71,6 +72,7 @@ static void RangeVarCallbackForReindexIndex(const RangeVar *rel, Oid relOid, Oid
 											oldRelOid,
 											void *arg);
 static void ErrorIfUnsupportedIndexStmt(IndexStmt *createIndexStatement);
+static void ErrorIfUnsupportedDropIndexStmt(DropStmt *dropIndexStatement);
 static List * DropIndexTaskList(Oid relationId, Oid indexId, DropStmt *dropStmt);
 
 
@@ -676,21 +678,9 @@ PreprocessDropIndexStmt(Node *node, const char *dropIndexCommand,
 		bool isCitusRelation = IsCitusTable(relationId);
 		if (isCitusRelation)
 		{
-			if (OidIsValid(distributedIndexId))
-			{
-				/*
-				 * We already have a distributed index in the list, and Citus
-				 * currently only support dropping a single distributed index.
-				 */
-				ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
-								errmsg("cannot drop multiple distributed objects in "
-									   "a single command"),
-								errhint("Try dropping each object in a separate DROP "
-										"command.")));
-			}
-
 			distributedIndexId = indexId;
 			distributedRelationId = relationId;
+			break;
 		}
 	}
 
@@ -698,6 +688,8 @@ PreprocessDropIndexStmt(Node *node, const char *dropIndexCommand,
 	{
 		DDLJob *ddlJob = palloc0(sizeof(DDLJob));
 
+		ErrorIfUnsupportedDropIndexStmt(dropIndexStatement);
+
 		if (AnyForeignKeyDependsOnIndex(distributedIndexId))
 		{
 			MarkInvalidateForeignKeyGraph();
@@ -1159,6 +1151,26 @@ ErrorIfUnsupportedIndexStmt(IndexStmt *createIndexStatement)
 }
 
 
+/*
+ * ErrorIfUnsupportedDropIndexStmt checks if the corresponding drop index statement is
+ * supported for distributed tables and errors out if it is not.
+ */
+static void
+ErrorIfUnsupportedDropIndexStmt(DropStmt *dropIndexStatement)
+{
+	Assert(dropIndexStatement->removeType == OBJECT_INDEX);
+
+	if (list_length(dropIndexStatement->objects) > 1)
+	{
+		ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+						errmsg("cannot drop multiple distributed objects in a "
+							   "single command"),
+						errhint("Try dropping each object in a separate DROP "
+								"command.")));
+	}
+}
+
+
 /*
  * DropIndexTaskList builds a list of tasks to execute a DROP INDEX command
  * against a specified distributed table.

src/test/regress/expected/multi_index_statements.out

@@ -255,16 +255,11 @@ DROP INDEX lineitem_orderkey_index, lineitem_partial_index;
 ERROR:  cannot drop multiple distributed objects in a single command
 HINT:  Try dropping each object in a separate DROP command.
 -- Verify that we can succesfully drop indexes
+DROP INDEX lineitem_orderkey_index;
+DROP INDEX lineitem_orderkey_index_new;
 DROP INDEX lineitem_partkey_desc_index;
 DROP INDEX lineitem_partial_index;
 DROP INDEX lineitem_colref_index;
--- Verify that we can drop distributed indexes with local indexes
-CREATE TABLE local_table(a int, b int);
-CREATE INDEX local_index ON local_table(a);
-CREATE INDEX local_index2 ON local_table(b);
-DROP INDEX lineitem_orderkey_index, local_index;
-DROP INDEX IF EXISTS lineitem_orderkey_index_new, local_index2, non_existing_index;
-NOTICE:  index "non_existing_index" does not exist, skipping
 -- Verify that we handle if exists statements correctly
 DROP INDEX non_existent_index;
 ERROR:  index "non_existent_index" does not exist

src/test/regress/multi_1_schedule

@@ -150,6 +150,7 @@ test: with_executors with_join with_partitioning with_transactions with_dml
 # ----------
 # Tests around DDL statements run on distributed tables
 # ----------
+test: multi_index_statements
 test: multi_alter_table_statements
 test: multi_alter_table_add_constraints
 
@@ -193,7 +194,6 @@ test: multi_repartition_udt multi_repartitioned_subquery_udf multi_subtransactio
 test: multi_modifying_xacts
 test: check_mx
 test: turn_mx_off
-test: multi_index_statements
 test: multi_generate_ddl_commands multi_repair_shards
 test: multi_create_shards
 test: multi_transaction_recovery

src/test/regress/sql/multi_index_statements.sql

@@ -159,17 +159,12 @@ REINDEX SYSTEM regression;
 DROP INDEX lineitem_orderkey_index, lineitem_partial_index;
 
 -- Verify that we can succesfully drop indexes
+DROP INDEX lineitem_orderkey_index;
+DROP INDEX lineitem_orderkey_index_new;
 DROP INDEX lineitem_partkey_desc_index;
 DROP INDEX lineitem_partial_index;
 DROP INDEX lineitem_colref_index;
 
--- Verify that we can drop distributed indexes with local indexes
-CREATE TABLE local_table(a int, b int);
-CREATE INDEX local_index ON local_table(a);
-CREATE INDEX local_index2 ON local_table(b);
-DROP INDEX lineitem_orderkey_index, local_index;
-DROP INDEX IF EXISTS lineitem_orderkey_index_new, local_index2, non_existing_index;
-
 -- Verify that we handle if exists statements correctly
 
 DROP INDEX non_existent_index;