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Refactor EnsureLocalTableEmptyIfNecessary (#3830)

pull/3832/head
Onur Tirtir 2020-05-15 14:20:33 +03:00 committed by GitHub
parent 8f3373c702
commit 249550b815
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1 changed files with 40 additions and 14 deletions
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54
src/backend/distributed/commands/create_distributed_table.c
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@ -102,7 +102,9 @@ static void EnsureTableNotDistributed(Oid relationId);
static Oid SupportFunctionForColumn(Var *partitionColumn, Oid accessMethodId, static Oid SupportFunctionForColumn(Var *partitionColumn, Oid accessMethodId,
int16 supportFunctionNumber); int16 supportFunctionNumber);
static void EnsureLocalTableEmptyIfNecessary(Oid relationId, char distributionMethod, static void EnsureLocalTableEmptyIfNecessary(Oid relationId, char distributionMethod,
bool viaDepracatedAPI); bool viaDeprecatedAPI);
static bool ShouldLocalTableBeEmpty(Oid relationId, char distributionMethod, bool
viaDeprecatedAPI);
static bool LocalTableEmpty(Oid tableId); static bool LocalTableEmpty(Oid tableId);
static void CopyLocalDataIntoShards(Oid relationId); static void CopyLocalDataIntoShards(Oid relationId);
static List * TupleDescColumnNameList(TupleDesc tupleDescriptor); static List * TupleDescColumnNameList(TupleDesc tupleDescriptor);
@ -849,33 +851,57 @@ EnsureTableCanBeColocatedWith(Oid relationId, char replicationModel,
/* /*
* EnsureLocalTableEmptyIfNecessary only checks for emptiness if only an empty * EnsureLocalTableEmptyIfNecessary errors out if the function should be empty
* relation can be distributed in given configuration. * according to ShouldLocalTableBeEmpty but it is not.
*
* In some cases, it is possible and safe to send local data to shards while
* distributing the table. In those cases, we can distribute non-empty local
* tables. This function checks the distributionMethod and relation kind to
* see whether we need to be ensure emptiness of local table. If we need to
* be sure, this function calls EnsureLocalTableEmpty function to ensure
* that local table does not contain any data.
*/ */
static void static void
EnsureLocalTableEmptyIfNecessary(Oid relationId, char distributionMethod, EnsureLocalTableEmptyIfNecessary(Oid relationId, char distributionMethod,
bool viaDepracatedAPI) bool viaDeprecatedAPI)
{ {
if (viaDepracatedAPI) if (ShouldLocalTableBeEmpty(relationId, distributionMethod, viaDeprecatedAPI))
{ {
EnsureLocalTableEmpty(relationId); EnsureLocalTableEmpty(relationId);
} }
}
/*
* ShouldLocalTableBeEmpty returns true if the local table should be empty
* before creating a citus table.
* In some cases, it is possible and safe to send local data to shards while
* distributing the table. In those cases, we can distribute non-empty local
* tables. This function checks the distributionMethod and relation kind to
* see whether we need to be ensure emptiness of local table.
*/
static bool
ShouldLocalTableBeEmpty(Oid relationId, char distributionMethod,
bool viaDeprecatedAPI)
{
bool shouldLocalTableBeEmpty = false;
if (viaDeprecatedAPI)
{
/* we don't support copying local data via deprecated API */
shouldLocalTableBeEmpty = true;
}
else if (distributionMethod != DISTRIBUTE_BY_HASH && else if (distributionMethod != DISTRIBUTE_BY_HASH &&
distributionMethod != DISTRIBUTE_BY_NONE) distributionMethod != DISTRIBUTE_BY_NONE)
{ {
EnsureLocalTableEmpty(relationId); /*
* We only support hash distributed tables and reference tables
* for initial data loading
*/
shouldLocalTableBeEmpty = true;
} }
else if (!RegularTable(relationId)) else if (!RegularTable(relationId))
{ {
EnsureLocalTableEmpty(relationId); /*
* We only support tables and partitioned tables for initial
* data loading
*/
shouldLocalTableBeEmpty = true;
} }
return shouldLocalTableBeEmpty;
} }