Fix copy from directory table. (#416)

We use temporary tupledesction in copy from directory table, which
will have no side effect on relcache.

Author: zhangwenchao-123

src/backend/commands/copyfrom.c

@@ -193,13 +193,14 @@ SendCopyFromForwardedTuple(CopyFromState cstate,
 						   char *line,
 						   int line_len,
 						   Datum *values,
-						   bool *nulls);
+						   bool *nulls,
+						   bool is_directory_table);
 static void SendCopyFromForwardedHeader(CopyFromState cstate, CdbCopy *cdbCopy);
 static void SendCopyFromForwardedError(CopyFromState cstate, CdbCopy *cdbCopy, char *errmsg);
 
 static bool NextCopyFromDispatch(CopyFromState cstate, ExprContext *econtext,
 								 Datum *values, bool *nulls);
-static bool NextCopyFromExecute(CopyFromState cstate, ExprContext *econtext, Datum *values, bool *nulls);
+static bool NextCopyFromExecute(CopyFromState cstate, ExprContext *econtext, Datum *values, bool *nulls, bool is_directory_table);
 static bool NextCopyFromRawFieldsX(CopyFromState cstate, char ***fields, int *nfields,
 								   int stop_processing_at_field);
 static bool NextCopyFromX(CopyFromState cstate, ExprContext *econtext,
@@ -1026,7 +1027,8 @@ CopyFromDirectoryTable(CopyFromState cstate)
 								   cstate->line_buf.data,
 								   cstate->line_buf.len,
 								   myslot->tts_values,
-								   myslot->tts_isnull);
+								   myslot->tts_isnull,
+								   true);
 		{
 			int64		total_completed_from_qes;
 			int64		total_rejected_from_qes;
@@ -1054,34 +1056,16 @@ CopyFromDirectoryTable(CopyFromState cstate)
 
 		econtext = GetPerTupleExprContext(estate);
 
-		if (NextCopyFromExecute(cstate, econtext, myslot->tts_values, myslot->tts_isnull))
+		if (NextCopyFromExecute(cstate, econtext, myslot->tts_values, myslot->tts_isnull, true))
 		{
-			if (tupdesc)
-				pfree(tupdesc);
-
-			tupdesc = CreateTemplateTupleDesc(DIRECTORY_TABLE_COLUMNS);
-			TupleDescInitEntry(tupdesc, (AttrNumber) 1, "relative_path",
-							   TEXTOID, -1, 0);
-			TupleDescInitEntry(tupdesc, (AttrNumber) 2, "size",
-							   INT8OID, -1, 0);
-			TupleDescInitEntry(tupdesc, (AttrNumber) 3, "last_modified",
-							   TIMESTAMPTZOID, -1, 0);
-			TupleDescInitEntry(tupdesc, (AttrNumber) 4, "md5",
-							   TEXTOID, -1, 0);
-			TupleDescInitEntry(tupdesc, (AttrNumber) 5, "tag",
-							   TEXTOID, -1 ,0);
-
-			tmpslot = MakeSingleTupleTableSlot(tupdesc, &TTSOpsVirtual);
+			tmpslot = MakeSingleTupleTableSlot(cstate->rel->rd_att, &TTSOpsVirtual);
 
 			for (i = 0; i < DIRECTORY_TABLE_COLUMNS; i++)
 			{
 				tmpslot->tts_values[i] = myslot->tts_values[i];
 				tmpslot->tts_isnull[i] = myslot->tts_isnull[i];
 			}
 
-			cstate->rel->rd_att = CreateTupleDescCopy(tupdesc);
-			cstate->rel->rd_att->tdrefcount = 1;	/* mark as refcounted */
-
 			/*
 			 * Reset the per-tuple exprcontext. We do this after every tuple, to
 			 * clean-up after expression evaluations etc.
@@ -1129,9 +1113,6 @@ CopyFromDirectoryTable(CopyFromState cstate)
 
 			list_free(recheckIndexes);
 
-			if (tupdesc)
-				pfree(tupdesc);
-
 			if (UFileExists(dirTable->spcId, orgiFileName))
 			{
 				UFileUnlink(dirTable->spcId, orgiFileName);
@@ -1174,7 +1155,8 @@ CopyFromDirectoryTable(CopyFromState cstate)
 							 errmsg("unable to sync file \"%s\": %s", glob_copystmt->dirfilename, UFileGetLastError(file))));
 
 			UFileClose(file);
-
+			
+			ReleaseTupleDesc(cstate->rel->rd_att);
 			ExecClearTuple(myslot);
 			ExecClearTuple(tmpslot);
 
@@ -1345,8 +1327,6 @@ BeginCopyFromDirectoryTable(ParseState *pstate,
 
 	num_phys_attrs = tupDesc->natts;
 
-	cstate->rel->rd_att = CreateTupleDescCopy(tupDesc);
-	cstate->rel->rd_att->tdrefcount = 1;	/* mark as refcounted */
 	cstate->attnumlist = CopyGetAttnums(tupDesc, cstate->rel, NIL);
 
 	/*
@@ -1929,7 +1909,7 @@ CopyFrom(CopyFromState cstate)
 
 		if (cstate->dispatch_mode == COPY_EXECUTOR)
 		{
-			if (!NextCopyFromExecute(cstate, econtext, myslot->tts_values, myslot->tts_isnull))
+			if (!NextCopyFromExecute(cstate, econtext, myslot->tts_values, myslot->tts_isnull, false))
 				break;
 
 			/*
@@ -2161,7 +2141,8 @@ CopyFrom(CopyFromState cstate)
 									   cstate->line_buf.data,
 									   cstate->line_buf.len,
 									   myslot->tts_values,
-									   myslot->tts_isnull);
+									   myslot->tts_isnull,
+									   false);
 			skip_tuple = true;
 			processed++;
 		}
@@ -3409,7 +3390,7 @@ NextCopyFromDispatch(CopyFromState cstate, ExprContext *econtext,
  * rows from the QD.
  */
 static bool
-NextCopyFromExecute(CopyFromState cstate, ExprContext *econtext, Datum *values, bool *nulls)
+NextCopyFromExecute(CopyFromState cstate, ExprContext *econtext, Datum *values, bool *nulls, bool is_directory_table)
 {
 	TupleDesc	tupDesc;
 	AttrNumber	num_phys_attrs,
@@ -3420,7 +3401,26 @@ NextCopyFromExecute(CopyFromState cstate, ExprContext *econtext, Datum *values,
 	int			r;
 	bool		got_error;
 
-	tupDesc = RelationGetDescr(cstate->rel);
+	if (!is_directory_table)
+	{
+		tupDesc = RelationGetDescr(cstate->rel);
+	}
+	else
+	{
+		tupDesc = CreateTemplateTupleDesc(6);
+		TupleDescInitEntry(tupDesc, (AttrNumber) 1, "relative_path",
+						   TEXTOID, -1, 0);
+		TupleDescInitEntry(tupDesc, (AttrNumber) 2, "size",
+						   INT8OID, -1, 0);
+		TupleDescInitEntry(tupDesc, (AttrNumber) 3, "last_modified",
+						   TIMESTAMPTZOID, -1, 0);
+		TupleDescInitEntry(tupDesc, (AttrNumber) 4, "md5",
+						   TEXTOID, -1, 0);
+		TupleDescInitEntry(tupDesc, (AttrNumber) 5, "tag",
+						   TEXTOID, -1 ,0);
+		TupleDescInitEntry(tupDesc, (AttrNumber) 6, "file",
+						   TEXTOID, -1, 0);
+	}
 	num_phys_attrs = tupDesc->natts;
 	attr_count = list_length(cstate->attnumlist);
 
@@ -3727,7 +3727,8 @@ SendCopyFromForwardedTuple(CopyFromState cstate,
 						   char *line,
 						   int line_len,
 						   Datum *values,
-						   bool *nulls)
+						   bool *nulls,
+						   bool is_directory_table)
 {
 	TupleDesc	tupDesc;
 	FormData_pg_attribute *attr;
@@ -3740,7 +3741,26 @@ SendCopyFromForwardedTuple(CopyFromState cstate,
 	if (!OidIsValid(RelationGetRelid(rel)))
 		elog(ERROR, "invalid target table OID in COPY");
 
-	tupDesc = RelationGetDescr(rel);
+	if (!is_directory_table)
+	{
+		tupDesc = RelationGetDescr(rel);
+	}
+	else
+	{
+		tupDesc = CreateTemplateTupleDesc(6);
+		TupleDescInitEntry(tupDesc, (AttrNumber) 1, "relative_path",
+						   TEXTOID, -1, 0);
+		TupleDescInitEntry(tupDesc, (AttrNumber) 2, "size",
+						   INT8OID, -1, 0);
+		TupleDescInitEntry(tupDesc, (AttrNumber) 3, "last_modified",
+						   TIMESTAMPTZOID, -1, 0);
+		TupleDescInitEntry(tupDesc, (AttrNumber) 4, "md5",
+						   TEXTOID, -1, 0);
+		TupleDescInitEntry(tupDesc, (AttrNumber) 5, "tag",
+						   TEXTOID, -1 ,0);
+		TupleDescInitEntry(tupDesc, (AttrNumber) 6, "file",
+						   TEXTOID, -1, 0);
+	}
 	attr = tupDesc->attrs;
 	num_phys_attrs = tupDesc->natts;