WIP Multi insert for logical replication apply

Author: BRupireddy2

src/backend/executor/execReplication.c

@@ -766,7 +766,7 @@ FindConflictTuple(ResultRelInfo *resultRelInfo, EState *estate,
  * Check all the unique indexes in 'recheckIndexes' for conflict with the
  * tuple in 'remoteslot' and report if found.
  */
-static void
+void
 CheckAndReportConflict(ResultRelInfo *resultRelInfo, EState *estate,
 					   ConflictType type, List *recheckIndexes,
 					   TupleTableSlot *searchslot, TupleTableSlot *remoteslot)

src/backend/replication/logical/proto.c

@@ -873,6 +873,7 @@ logicalrep_read_tuple(StringInfo in, LogicalRepTupleData *tuple)
 	tuple->colvalues = palloc0_array(StringInfoData, natts);
 	tuple->colstatus = palloc_array(char, natts);
 	tuple->ncols = natts;
+	tuple->datasize = 0;
 
 	/* Read the data */
 	for (i = 0; i < natts; i++)
@@ -897,6 +898,9 @@ logicalrep_read_tuple(StringInfo in, LogicalRepTupleData *tuple)
 			case LOGICALREP_COLUMN_BINARY:
 				len = pq_getmsgint(in, 4);	/* read length */
 
+				/* accumulate received value length for buffering estimates */
+				tuple->datasize += len;
+
 				/* and data */
 				buff = palloc(len + 1);
 				pq_copymsgbytes(in, buff, len);