citus/src/backend/distributed/utils/shard_utils.c

58 lines
1.6 KiB
C

/*-------------------------------------------------------------------------
*
* shard_utils.c
*
* This file contains functions to perform useful operations on shards.
*
* Copyright (c) Citus Data, Inc.
*
*-------------------------------------------------------------------------
*/
#include "postgres.h"
#include "utils/lsyscache.h"
#include "distributed/metadata_utility.h"
#include "distributed/relay_utility.h"
#include "distributed/shard_utils.h"
/*
* GetTableLocalShardOid returns the oid of the shard from the given distributed
* relation with the shardId.
*/
Oid
GetTableLocalShardOid(Oid citusTableOid, uint64 shardId)
{
const char *citusTableName = get_rel_name(citusTableOid);
Assert(citusTableName != NULL);
/* construct shard relation name */
char *shardRelationName = pstrdup(citusTableName);
AppendShardIdToName(&shardRelationName, shardId);
Oid citusTableSchemaOid = get_rel_namespace(citusTableOid);
Oid shardRelationOid = get_relname_relid(shardRelationName, citusTableSchemaOid);
return shardRelationOid;
}
/*
* GetLongestShardName is a utility function that returns the name of the shard of a
* table that has the longest name in terms of number of characters.
*
* Both the Oid and name of the table are required so we can create longest shard names
* after a RENAME.
*/
char *
GetLongestShardName(Oid citusTableOid, char *finalRelationName)
{
char *longestShardName = pstrdup(finalRelationName);
ShardInterval *shardInterval = LoadShardIntervalWithLongestShardName(citusTableOid);
AppendShardIdToName(&longestShardName, shardInterval->shardId);
return longestShardName;
}