diff --git a/src/backend/bootstrap/bootparse.y b/src/backend/bootstrap/bootparse.y
index de3695c..2e1fef0 100644
*** a/src/backend/bootstrap/bootparse.y
--- b/src/backend/bootstrap/bootparse.y
*************** Boot_DeclareIndexStmt:
*** 323,328 ****
--- 323,329 ----
  								$4,
  								false,
  								false,
+ 								false,
  								true, /* skip_build */
  								false);
  					do_end();
*************** Boot_DeclareUniqueIndexStmt:
*** 366,371 ****
--- 367,373 ----
  								$5,
  								false,
  								false,
+ 								false,
  								true, /* skip_build */
  								false);
  					do_end();
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 4861799..c090279 100644
*** a/src/backend/commands/indexcmds.c
--- b/src/backend/commands/indexcmds.c
*************** CheckIndexCompatible(Oid oldId,
*** 295,300 ****
--- 295,303 ----
   * 'is_alter_table': this is due to an ALTER rather than a CREATE operation.
   * 'check_rights': check for CREATE rights in namespace and tablespace.  (This
   *		should be true except when ALTER is deleting/recreating an index.)
+  * 'check_not_in_use': check for table not already in use in current session.
+  *		This should be true unless caller is holding the table open, in which
+  *		case the caller had better have checked it earlier.
   * 'skip_build': make the catalog entries but leave the index file empty;
   *		it will be filled later.
   * 'quiet': suppress the NOTICE chatter ordinarily provided for constraints.
*************** DefineIndex(Oid relationId,
*** 307,312 ****
--- 310,316 ----
  			Oid indexRelationId,
  			bool is_alter_table,
  			bool check_rights,
+ 			bool check_not_in_use,
  			bool skip_build,
  			bool quiet)
  {
*************** DefineIndex(Oid relationId,
*** 405,410 ****
--- 409,423 ----
  				 errmsg("cannot create indexes on temporary tables of other sessions")));
  
  	/*
+ 	 * Unless our caller vouches for having checked this already, insist that
+ 	 * the table not be in use by our own session, either.  Otherwise we might
+ 	 * fail to make entries in the new index (for instance, if an INSERT or
+ 	 * UPDATE is in progress and has already made its list of target indexes).
+ 	 */
+ 	if (check_not_in_use)
+ 		CheckTableNotInUse(rel, "CREATE INDEX");
+ 
+ 	/*
  	 * Verify we (still) have CREATE rights in the rel's namespace.
  	 * (Presumably we did when the rel was created, but maybe not anymore.)
  	 * Skip check if caller doesn't want it.  Also skip check if
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 7959120..b61fda9 100644
*** a/src/backend/commands/tablecmds.c
--- b/src/backend/commands/tablecmds.c
*************** ATExecAddIndex(AlteredTableInfo *tab, Re
*** 6679,6684 ****
--- 6679,6685 ----
  						  InvalidOid,	/* no predefined OID */
  						  true, /* is_alter_table */
  						  check_rights,
+ 						  false,	/* check_not_in_use - we did it already */
  						  skip_build,
  						  quiet);
  
diff --git a/src/backend/tcop/utility.c b/src/backend/tcop/utility.c
index 1e941fb..a22fd53 100644
*** a/src/backend/tcop/utility.c
--- b/src/backend/tcop/utility.c
*************** ProcessUtilitySlow(ParseState *pstate,
*** 1329,1334 ****
--- 1329,1335 ----
  									InvalidOid, /* no predefined OID */
  									false,		/* is_alter_table */
  									true,		/* check_rights */
+ 									true,		/* check_not_in_use */
  									false,		/* skip_build */
  									false);		/* quiet */
  
diff --git a/src/include/commands/defrem.h b/src/include/commands/defrem.h
index 79f3be3..5dd14b4 100644
*** a/src/include/commands/defrem.h
--- b/src/include/commands/defrem.h
*************** extern ObjectAddress DefineIndex(Oid rel
*** 27,32 ****
--- 27,33 ----
  			Oid indexRelationId,
  			bool is_alter_table,
  			bool check_rights,
+ 			bool check_not_in_use,
  			bool skip_build,
  			bool quiet);
  extern Oid	ReindexIndex(RangeVar *indexRelation, int options);