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Separate controls 

Separte controls to make checks before and after query running on master
pull/1288/head
velioglu 2017-03-22 09:50:53 +03:00
parent 4390bc09c3
commit 697084b532
4 changed files with 390 additions and 400 deletions
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348
src/backend/distributed/commands/create_distributed_table.c
View File

@ -35,7 +35,6 @@
#include "commands/extension.h"
#include "commands/trigger.h"
#include "distributed/colocation_utils.h"
#include "distributed/create_distributed_table.h"
#include "distributed/distribution_column.h"
#include "distributed/master_metadata_utility.h"
#include "distributed/master_protocol.h"
@ -43,6 +42,7 @@
#include "distributed/metadata_sync.h"
#include "distributed/multi_copy.h"
#include "distributed/multi_logical_planner.h"
#include "distributed/multi_utility.h"
#include "distributed/pg_dist_colocation.h"
#include "distributed/pg_dist_partition.h"
#include "distributed/reference_table_utils.h"
@ -82,10 +82,6 @@ static char LookupDistributionMethod(Oid distributionMethodOid);
static Oid SupportFunctionForColumn(Var *partitionColumn, Oid accessMethodId,
int16 supportFunctionNumber);
static bool LocalTableEmpty(Oid tableId);
static void ErrorIfNotSupportedForeignConstraint(Relation relation,
char distributionMethod,
Var *distributionColumn,
uint32 colocationId);
static void CreateHashDistributedTable(Oid relationId, char *distributionColumnName,
char *colocateWithTableName,
int shardCount, int replicationFactor);
@ -419,348 +415,6 @@ ConvertToDistributedTable(Oid relationId, char *distributionColumnName,
}
/*
* ErrorIfNotSupportedConstraint run checks related to unique index / exclude
* constraints.
*
* The function skips the uniqeness checks for reference tables (i.e., distribution
* method is 'none').
*
* Forbid UNIQUE, PRIMARY KEY, or EXCLUDE constraints on append partitioned
* tables, since currently there is no way of enforcing uniqueness for
* overlapping shards.
*
* Similarly, do not allow such constraints if they do not include partition
* column. This check is important for two reasons:
* i. First, currently Citus does not enforce uniqueness constraint on multiple
* shards.
* ii. Second, INSERT INTO .. ON CONFLICT (i.e., UPSERT) queries can be executed
* with no further check for constraints.
*/
void
ErrorIfNotSupportedConstraint(Relation relation, char distributionMethod,
Var *distributionColumn, uint32 colocationId)
{
char *relationName = NULL;
List *indexOidList = NULL;
ListCell *indexOidCell = NULL;
/*
* We first perform check for foreign constraints. It is important to do this check
* before next check, because other types of constraints are allowed on reference
* tables and we return early for those constraints thanks to next check. Therefore,
* for reference tables, we first check for foreing constraints and if they are OK,
* we do not error out for other types of constraints.
*/
ErrorIfNotSupportedForeignConstraint(relation, distributionMethod, distributionColumn,
colocationId);
/*
* Citus supports any kind of uniqueness constraints for reference tables
* given that they only consist of a single shard and we can simply rely on
* Postgres.
*/
if (distributionMethod == DISTRIBUTE_BY_NONE)
{
return;
}
relationName = RelationGetRelationName(relation);
indexOidList = RelationGetIndexList(relation);
foreach(indexOidCell, indexOidList)
{
Oid indexOid = lfirst_oid(indexOidCell);
Relation indexDesc = index_open(indexOid, RowExclusiveLock);
IndexInfo *indexInfo = NULL;
AttrNumber *attributeNumberArray = NULL;
bool hasDistributionColumn = false;
int attributeCount = 0;
int attributeIndex = 0;
/* extract index key information from the index's pg_index info */
indexInfo = BuildIndexInfo(indexDesc);
/* only check unique indexes and exclusion constraints. */
if (indexInfo->ii_Unique == false && indexInfo->ii_ExclusionOps == NULL)
{
index_close(indexDesc, NoLock);
continue;
}
/*
* Citus cannot enforce uniqueness/exclusion constraints with overlapping shards.
* Thus, emit a warning for unique indexes and exclusion constraints on
* append partitioned tables.
*/
if (distributionMethod == DISTRIBUTE_BY_APPEND)
{
ereport(WARNING, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("table \"%s\" has a UNIQUE or EXCLUDE constraint",
relationName),
errdetail("UNIQUE constraints, EXCLUDE constraints, "
"and PRIMARY KEYs on "
"append-partitioned tables cannot be enforced."),
errhint("Consider using hash partitioning.")));
}
attributeCount = indexInfo->ii_NumIndexAttrs;
attributeNumberArray = indexInfo->ii_KeyAttrNumbers;
for (attributeIndex = 0; attributeIndex < attributeCount; attributeIndex++)
{
AttrNumber attributeNumber = attributeNumberArray[attributeIndex];
bool uniqueConstraint = false;
bool exclusionConstraintWithEquality = false;
if (distributionColumn->varattno != attributeNumber)
{
continue;
}
uniqueConstraint = indexInfo->ii_Unique;
exclusionConstraintWithEquality = (indexInfo->ii_ExclusionOps != NULL &&
OperatorImplementsEquality(
indexInfo->ii_ExclusionOps[
attributeIndex]));
if (uniqueConstraint || exclusionConstraintWithEquality)
{
hasDistributionColumn = true;
break;
}
}
if (!hasDistributionColumn)
{
ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("cannot distribute relation: \"%s\"",
relationName),
errdetail("Distributed relations cannot have UNIQUE, "
"EXCLUDE, or PRIMARY KEY constraints that do not "
"include the partition column (with an equality "
"operator if EXCLUDE).")));
}
index_close(indexDesc, NoLock);
}
}
/*
* ErrorIfNotSupportedForeignConstraint runs checks related to foreign constraints and
* errors out if it is not possible to create one of the foreign constraint in distributed
* environment.
*
* To support foreign constraints, we require that;
* - Referencing and referenced tables are hash distributed.
* - Referencing and referenced tables are co-located.
* - Foreign constraint is defined over distribution column.
* - ON DELETE/UPDATE SET NULL, ON DELETE/UPDATE SET DEFAULT and ON UPDATE CASCADE options
* are not used.
* - Replication factors of referencing and referenced table are 1.
*/
static void
ErrorIfNotSupportedForeignConstraint(Relation relation, char distributionMethod,
Var *distributionColumn, uint32 colocationId)
{
Relation pgConstraint = NULL;
SysScanDesc scanDescriptor = NULL;
ScanKeyData scanKey[1];
int scanKeyCount = 1;
HeapTuple heapTuple = NULL;
Oid referencedTableId = InvalidOid;
uint32 referencedTableColocationId = INVALID_COLOCATION_ID;
Var *referencedTablePartitionColumn = NULL;
Datum referencingColumnsDatum;
Datum *referencingColumnArray;
int referencingColumnCount = 0;
Datum referencedColumnsDatum;
Datum *referencedColumnArray;
int referencedColumnCount = 0;
bool isNull = false;
int attrIdx = 0;
bool foreignConstraintOnPartitionColumn = false;
bool selfReferencingTable = false;
pgConstraint = heap_open(ConstraintRelationId, AccessShareLock);
ScanKeyInit(&scanKey[0], Anum_pg_constraint_conrelid, BTEqualStrategyNumber, F_OIDEQ,
relation->rd_id);
scanDescriptor = systable_beginscan(pgConstraint, ConstraintRelidIndexId, true, NULL,
scanKeyCount, scanKey);
heapTuple = systable_getnext(scanDescriptor);
while (HeapTupleIsValid(heapTuple))
{
Form_pg_constraint constraintForm = (Form_pg_constraint) GETSTRUCT(heapTuple);
if (constraintForm->contype != CONSTRAINT_FOREIGN)
{
heapTuple = systable_getnext(scanDescriptor);
continue;
}
referencedTableId = constraintForm->confrelid;
selfReferencingTable = relation->rd_id == referencedTableId;
/*
* We do not support foreign keys for reference tables. Here we skip the second
* part of check if the table is a self referencing table because;
* - PartitionMethod only works for distributed tables and this table is not
* distributed yet.
* - Since referencing and referenced tables are same, it is OK to not checking
* distribution method twice.
*/
if (distributionMethod == DISTRIBUTE_BY_NONE ||
(!selfReferencingTable &&
PartitionMethod(referencedTableId) == DISTRIBUTE_BY_NONE))
{
ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("cannot create foreign key constraint"),
errdetail("Foreign key constraints are not allowed from or "
"to reference tables.")));
}
/*
* ON DELETE SET NULL and ON DELETE SET DEFAULT is not supported. Because we do
* not want to set partition column to NULL or default value.
*/
if (constraintForm->confdeltype == FKCONSTR_ACTION_SETNULL ||
constraintForm->confdeltype == FKCONSTR_ACTION_SETDEFAULT)
{
ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("cannot create foreign key constraint"),
errdetail("SET NULL or SET DEFAULT is not supported"
" in ON DELETE operation.")));
}
/*
* ON UPDATE SET NULL, ON UPDATE SET DEFAULT and UPDATE CASCADE is not supported.
* Because we do not want to set partition column to NULL or default value. Also
* cascading update operation would require re-partitioning. Updating partition
* column value is not allowed anyway even outside of foreign key concept.
*/
if (constraintForm->confupdtype == FKCONSTR_ACTION_SETNULL ||
constraintForm->confupdtype == FKCONSTR_ACTION_SETDEFAULT ||
constraintForm->confupdtype == FKCONSTR_ACTION_CASCADE)
{
ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("cannot create foreign key constraint"),
errdetail("SET NULL, SET DEFAULT or CASCADE is not"
" supported in ON UPDATE operation.")));
}
/*
* Some checks are not meaningful if foreign key references the table itself.
* Therefore we will skip those checks.
*/
if (!selfReferencingTable)
{
if (!IsDistributedTable(referencedTableId))
{
ereport(ERROR, (errcode(ERRCODE_INVALID_TABLE_DEFINITION),
errmsg("cannot create foreign key constraint"),
errdetail("Referenced table must be a distributed "
"table.")));
}
/* to enforce foreign constraints, tables must be co-located */
referencedTableColocationId = TableColocationId(referencedTableId);
if (relation->rd_id != referencedTableId &&
(colocationId == INVALID_COLOCATION_ID ||
colocationId != referencedTableColocationId))
{
ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("cannot create foreign key constraint"),
errdetail("Foreign key constraint can only be created"
" on co-located tables.")));
}
/*
* Partition column must exist in both referencing and referenced side of the
* foreign key constraint. They also must be in same ordinal.
*/
referencedTablePartitionColumn = PartitionKey(referencedTableId);
}
else
{
/*
* Partition column must exist in both referencing and referenced side of the
* foreign key constraint. They also must be in same ordinal.
*/
referencedTablePartitionColumn = distributionColumn;
}
/*
* Column attributes are not available in Form_pg_constraint, therefore we need
* to find them in the system catalog. After finding them, we iterate over column
* attributes together because partition column must be at the same place in both
* referencing and referenced side of the foreign key constraint
*/
referencingColumnsDatum = SysCacheGetAttr(CONSTROID, heapTuple,
Anum_pg_constraint_conkey, &isNull);
referencedColumnsDatum = SysCacheGetAttr(CONSTROID, heapTuple,
Anum_pg_constraint_confkey, &isNull);
deconstruct_array(DatumGetArrayTypeP(referencingColumnsDatum), INT2OID, 2, true,
's', &referencingColumnArray, NULL, &referencingColumnCount);
deconstruct_array(DatumGetArrayTypeP(referencedColumnsDatum), INT2OID, 2, true,
's', &referencedColumnArray, NULL, &referencedColumnCount);
Assert(referencingColumnCount == referencedColumnCount);
for (attrIdx = 0; attrIdx < referencingColumnCount; ++attrIdx)
{
AttrNumber referencingAttrNo = DatumGetInt16(referencingColumnArray[attrIdx]);
AttrNumber referencedAttrNo = DatumGetInt16(referencedColumnArray[attrIdx]);
if (distributionColumn->varattno == referencingAttrNo &&
referencedTablePartitionColumn->varattno == referencedAttrNo)
{
foreignConstraintOnPartitionColumn = true;
}
}
if (!foreignConstraintOnPartitionColumn)
{
ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("cannot create foreign key constraint"),
errdetail("Partition column must exist both "
"referencing and referenced side of the "
"foreign constraint statement and it must "
"be in the same ordinal in both sides.")));
}
/*
* We do not allow to create foreign constraints if shard replication factor is
* greater than 1. Because in our current design, multiple replicas may cause
* locking problems and inconsistent shard contents.
*/
if (ShardReplicationFactor > 1 || (referencedTableId != relation->rd_id &&
!SingleReplicatedTable(referencedTableId)))
{
ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("cannot create foreign key constraint"),
errdetail("Citus Community Edition currently supports "
"foreign key constraints only for "
"\"citus.shard_replication_factor = 1\"."),
errhint("Please change \"citus.shard_replication_factor to "
"1\". To learn more about using foreign keys with "
"other replication factors, please contact us at "
"https://citusdata.com/about/contact_us.")));
}
heapTuple = systable_getnext(scanDescriptor);
}
/* clean up scan and close system catalog */
systable_endscan(scanDescriptor);
heap_close(pgConstraint, AccessShareLock);
}
/*
* LookupDistributionMethod maps the oids of citus.distribution_type enum
* values to pg_dist_partition.partmethod values.

419
src/backend/distributed/executor/multi_utility.c
View File

@ -24,15 +24,20 @@
#include "catalog/catalog.h"
#include "catalog/dependency.h"
#include "catalog/index.h"
#include "catalog/indexing.h"
#include "catalog/namespace.h"
#include "catalog/pg_attribute.h"
#include "catalog/pg_class.h"
#include "catalog/pg_constraint.h"
#if (PG_VERSION_NUM >= 90600)
#include "catalog/pg_constraint_fn.h"
#endif
#include "catalog/pg_type.h"
#include "commands/defrem.h"
#include "commands/tablecmds.h"
#include "commands/prepare.h"
#include "distributed/citus_ruleutils.h"
#include "distributed/colocation_utils.h"
#include "distributed/create_distributed_table.h"
#include "distributed/master_metadata_utility.h"
#include "distributed/master_protocol.h"
#include "distributed/metadata_cache.h"
@ -69,6 +74,7 @@
#include "utils/builtins.h"
#include "utils/elog.h"
#include "utils/errcodes.h"
#include "utils/fmgroids.h"
#include "utils/guc.h"
#include "utils/hsearch.h"
#include "utils/inval.h"
@ -1364,40 +1370,6 @@ ErrorIfUnsupportedDropIndexStmt(DropStmt *dropIndexStatement)
}
static void
ErrorIfUnsupportedAlterAddConstraintStmt(AlterTableStmt *alterTableStatement)
{
Oid relationId = InvalidOid;
bool isDistributedRelation = false;
LOCKMODE lockmode = 0;
Relation relation = NULL;
char distributionMethod;
Var *distributionColumn = NULL;
uint32 colocationId = 0;
/* continue if it is not distributed table */
lockmode = AlterTableGetLockLevel(alterTableStatement->cmds);
relationId = AlterTableLookupRelation(alterTableStatement, lockmode);
isDistributedRelation = IsDistributedTable(relationId);
if (!isDistributedRelation)
{
return;
}
distributionMethod = PartitionMethod(relationId);
distributionColumn = PartitionKey(relationId);
colocationId = TableColocationId(relationId);
relation = relation_open(relationId, ExclusiveLock);
ErrorIfNotSupportedConstraint(relation, distributionMethod,
distributionColumn, colocationId);
relation_close(relation, NoLock);
}
/*
* ErrorIfUnsupportedAlterTableStmt checks if the corresponding alter table statement
* is supported for distributed tables and errors out if it is not. Currently,
@ -1487,7 +1459,7 @@ ErrorIfUnsupportedAlterTableStmt(AlterTableStmt *alterTableStatement)
/* reference tables do not have partition column, so allow them */
if (partitionColumn != NULL &&
targetAttr->attnum == partitionColumn->varattno)
{ /* TODO : CHANGE IT ! */
{
ereport(ERROR, (errmsg("cannot execute ALTER TABLE command "
"involving partition column")));
}
@ -1547,6 +1519,381 @@ ErrorIfUnsupportedAlterTableStmt(AlterTableStmt *alterTableStatement)
}
/*
* ErrorIfNotSupportedConstraint run checks related to unique index / exclude
* constraints.
*
* The function skips the uniqeness checks for reference tables (i.e., distribution
* method is 'none').
*
* Forbid UNIQUE, PRIMARY KEY, or EXCLUDE constraints on append partitioned
* tables, since currently there is no way of enforcing uniqueness for
* overlapping shards.
*
* Similarly, do not allow such constraints if they do not include partition
* column. This check is important for two reasons:
* i. First, currently Citus does not enforce uniqueness constraint on multiple
* shards.
* ii. Second, INSERT INTO .. ON CONFLICT (i.e., UPSERT) queries can be executed
* with no further check for constraints.
*/
void
ErrorIfNotSupportedConstraint(Relation relation, char distributionMethod,
Var *distributionColumn, uint32 colocationId)
{
char *relationName = NULL;
List *indexOidList = NULL;
ListCell *indexOidCell = NULL;
/*
* We first perform check for foreign constraints. It is important to do this check
* before next check, because other types of constraints are allowed on reference
* tables and we return early for those constraints thanks to next check. Therefore,
* for reference tables, we first check for foreing constraints and if they are OK,
* we do not error out for other types of constraints.
*/
ErrorIfNotSupportedForeignConstraint(relation, distributionMethod, distributionColumn,
colocationId);
/*
* Citus supports any kind of uniqueness constraints for reference tables
* given that they only consist of a single shard and we can simply rely on
* Postgres.
*/
if (distributionMethod == DISTRIBUTE_BY_NONE)
{
return;
}
relationName = RelationGetRelationName(relation);
indexOidList = RelationGetIndexList(relation);
foreach(indexOidCell, indexOidList)
{
Oid indexOid = lfirst_oid(indexOidCell);
Relation indexDesc = index_open(indexOid, RowExclusiveLock);
IndexInfo *indexInfo = NULL;
AttrNumber *attributeNumberArray = NULL;
bool hasDistributionColumn = false;
int attributeCount = 0;
int attributeIndex = 0;
/* extract index key information from the index's pg_index info */
indexInfo = BuildIndexInfo(indexDesc);
/* only check unique indexes and exclusion constraints. */
if (indexInfo->ii_Unique == false && indexInfo->ii_ExclusionOps == NULL)
{
index_close(indexDesc, NoLock);
continue;
}
/*
* Citus cannot enforce uniqueness/exclusion constraints with overlapping shards.
* Thus, emit a warning for unique indexes and exclusion constraints on
* append partitioned tables.
*/
if (distributionMethod == DISTRIBUTE_BY_APPEND)
{
ereport(WARNING, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("table \"%s\" has a UNIQUE or EXCLUDE constraint",
relationName),
errdetail("UNIQUE constraints, EXCLUDE constraints, "
"and PRIMARY KEYs on "
"append-partitioned tables cannot be enforced."),
errhint("Consider using hash partitioning.")));
}
attributeCount = indexInfo->ii_NumIndexAttrs;
attributeNumberArray = indexInfo->ii_KeyAttrNumbers;
for (attributeIndex = 0; attributeIndex < attributeCount; attributeIndex++)
{
AttrNumber attributeNumber = attributeNumberArray[attributeIndex];
bool uniqueConstraint = false;
bool exclusionConstraintWithEquality = false;
if (distributionColumn->varattno != attributeNumber)
{
continue;
}
uniqueConstraint = indexInfo->ii_Unique;
exclusionConstraintWithEquality = (indexInfo->ii_ExclusionOps != NULL &&
OperatorImplementsEquality(
indexInfo->ii_ExclusionOps[
attributeIndex]));
if (uniqueConstraint || exclusionConstraintWithEquality)
{
hasDistributionColumn = true;
break;
}
}
if (!hasDistributionColumn)
{
ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("cannot distribute relation: \"%s\"",
relationName),
errdetail("Distributed relations cannot have UNIQUE, "
"EXCLUDE, or PRIMARY KEY constraints that do not "
"include the partition column (with an equality "
"operator if EXCLUDE).")));
}
index_close(indexDesc, NoLock);
}
}
/*
* ErrorIfNotSupportedForeignConstraint runs checks related to foreign constraints and
* errors out if it is not possible to create one of the foreign constraint in distributed
* environment.
*
* To support foreign constraints, we require that;
* - Referencing and referenced tables are hash distributed.
* - Referencing and referenced tables are co-located.
* - Foreign constraint is defined over distribution column.
* - ON DELETE/UPDATE SET NULL, ON DELETE/UPDATE SET DEFAULT and ON UPDATE CASCADE options
* are not used.
* - Replication factors of referencing and referenced table are 1.
*/
void
ErrorIfNotSupportedForeignConstraint(Relation relation, char distributionMethod,
Var *distributionColumn, uint32 colocationId)
{
Relation pgConstraint = NULL;
SysScanDesc scanDescriptor = NULL;
ScanKeyData scanKey[1];
int scanKeyCount = 1;
HeapTuple heapTuple = NULL;
Oid referencedTableId = InvalidOid;
uint32 referencedTableColocationId = INVALID_COLOCATION_ID;
Var *referencedTablePartitionColumn = NULL;
Datum referencingColumnsDatum;
Datum *referencingColumnArray;
int referencingColumnCount = 0;
Datum referencedColumnsDatum;
Datum *referencedColumnArray;
int referencedColumnCount = 0;
bool isNull = false;
int attrIdx = 0;
bool foreignConstraintOnPartitionColumn = false;
bool selfReferencingTable = false;
pgConstraint = heap_open(ConstraintRelationId, AccessShareLock);
ScanKeyInit(&scanKey[0], Anum_pg_constraint_conrelid, BTEqualStrategyNumber, F_OIDEQ,
relation->rd_id);
scanDescriptor = systable_beginscan(pgConstraint, ConstraintRelidIndexId, true, NULL,
scanKeyCount, scanKey);
heapTuple = systable_getnext(scanDescriptor);
while (HeapTupleIsValid(heapTuple))
{
Form_pg_constraint constraintForm = (Form_pg_constraint) GETSTRUCT(heapTuple);
if (constraintForm->contype != CONSTRAINT_FOREIGN)
{
heapTuple = systable_getnext(scanDescriptor);
continue;
}
referencedTableId = constraintForm->confrelid;
selfReferencingTable = relation->rd_id == referencedTableId;
/*
* We do not support foreign keys for reference tables. Here we skip the second
* part of check if the table is a self referencing table because;
* - PartitionMethod only works for distributed tables and this table is not
* distributed yet.
* - Since referencing and referenced tables are same, it is OK to not checking
* distribution method twice.
*/
if (distributionMethod == DISTRIBUTE_BY_NONE ||
(!selfReferencingTable &&
PartitionMethod(referencedTableId) == DISTRIBUTE_BY_NONE))
{
ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("cannot create foreign key constraint"),
errdetail("Foreign key constraints are not allowed from or "
"to reference tables.")));
}
/*
* ON DELETE SET NULL and ON DELETE SET DEFAULT is not supported. Because we do
* not want to set partition column to NULL or default value.
*/
if (constraintForm->confdeltype == FKCONSTR_ACTION_SETNULL ||
constraintForm->confdeltype == FKCONSTR_ACTION_SETDEFAULT)
{
ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("cannot create foreign key constraint"),
errdetail("SET NULL or SET DEFAULT is not supported"
" in ON DELETE operation.")));
}
/*
* ON UPDATE SET NULL, ON UPDATE SET DEFAULT and UPDATE CASCADE is not supported.
* Because we do not want to set partition column to NULL or default value. Also
* cascading update operation would require re-partitioning. Updating partition
* column value is not allowed anyway even outside of foreign key concept.
*/
if (constraintForm->confupdtype == FKCONSTR_ACTION_SETNULL ||
constraintForm->confupdtype == FKCONSTR_ACTION_SETDEFAULT ||
constraintForm->confupdtype == FKCONSTR_ACTION_CASCADE)
{
ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("cannot create foreign key constraint"),
errdetail("SET NULL, SET DEFAULT or CASCADE is not"
" supported in ON UPDATE operation.")));
}
/*
* Some checks are not meaningful if foreign key references the table itself.
* Therefore we will skip those checks.
*/
if (!selfReferencingTable)
{
if (!IsDistributedTable(referencedTableId))
{
ereport(ERROR, (errcode(ERRCODE_INVALID_TABLE_DEFINITION),
errmsg("cannot create foreign key constraint"),
errdetail("Referenced table must be a distributed "
"table.")));
}
/* to enforce foreign constraints, tables must be co-located */
referencedTableColocationId = TableColocationId(referencedTableId);
if (relation->rd_id != referencedTableId &&
(colocationId == INVALID_COLOCATION_ID ||
colocationId != referencedTableColocationId))
{
ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("cannot create foreign key constraint"),
errdetail("Foreign key constraint can only be created"
" on co-located tables.")));
}
/*
* Partition column must exist in both referencing and referenced side of the
* foreign key constraint. They also must be in same ordinal.
*/
referencedTablePartitionColumn = PartitionKey(referencedTableId);
}
else
{
/*
* Partition column must exist in both referencing and referenced side of the
* foreign key constraint. They also must be in same ordinal.
*/
referencedTablePartitionColumn = distributionColumn;
}
/*
* Column attributes are not available in Form_pg_constraint, therefore we need
* to find them in the system catalog. After finding them, we iterate over column
* attributes together because partition column must be at the same place in both
* referencing and referenced side of the foreign key constraint
*/
referencingColumnsDatum = SysCacheGetAttr(CONSTROID, heapTuple,
Anum_pg_constraint_conkey, &isNull);
referencedColumnsDatum = SysCacheGetAttr(CONSTROID, heapTuple,
Anum_pg_constraint_confkey, &isNull);
deconstruct_array(DatumGetArrayTypeP(referencingColumnsDatum), INT2OID, 2, true,
's', &referencingColumnArray, NULL, &referencingColumnCount);
deconstruct_array(DatumGetArrayTypeP(referencedColumnsDatum), INT2OID, 2, true,
's', &referencedColumnArray, NULL, &referencedColumnCount);
Assert(referencingColumnCount == referencedColumnCount);
for (attrIdx = 0; attrIdx < referencingColumnCount; ++attrIdx)
{
AttrNumber referencingAttrNo = DatumGetInt16(referencingColumnArray[attrIdx]);
AttrNumber referencedAttrNo = DatumGetInt16(referencedColumnArray[attrIdx]);
if (distributionColumn->varattno == referencingAttrNo &&
referencedTablePartitionColumn->varattno == referencedAttrNo)
{
foreignConstraintOnPartitionColumn = true;
}
}
if (!foreignConstraintOnPartitionColumn)
{
ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("cannot create foreign key constraint"),
errdetail("Partition column must exist both "
"referencing and referenced side of the "
"foreign constraint statement and it must "
"be in the same ordinal in both sides.")));
}
/*
* We do not allow to create foreign constraints if shard replication factor is
* greater than 1. Because in our current design, multiple replicas may cause
* locking problems and inconsistent shard contents.
*/
if (ShardReplicationFactor > 1 || (referencedTableId != relation->rd_id &&
!SingleReplicatedTable(referencedTableId)))
{
ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("cannot create foreign key constraint"),
errdetail("Citus Community Edition currently supports "
"foreign key constraints only for "
"\"citus.shard_replication_factor = 1\"."),
errhint("Please change \"citus.shard_replication_factor to "
"1\". To learn more about using foreign keys with "
"other replication factors, please contact us at "
"https://citusdata.com/about/contact_us.")));
}
heapTuple = systable_getnext(scanDescriptor);
}
/* clean up scan and close system catalog */
systable_endscan(scanDescriptor);
heap_close(pgConstraint, AccessShareLock);
}
static void
ErrorIfUnsupportedAlterAddConstraintStmt(AlterTableStmt *alterTableStatement)
{
Oid relationId = InvalidOid;
bool isDistributedRelation = false;
LOCKMODE lockmode = 0;
Relation relation = NULL;
char distributionMethod;
Var *distributionColumn = NULL;
uint32 colocationId = 0;
/* continue if it is not distributed table */
lockmode = AlterTableGetLockLevel(alterTableStatement->cmds);
relationId = AlterTableLookupRelation(alterTableStatement, lockmode);
isDistributedRelation = IsDistributedTable(relationId);
if (!isDistributedRelation)
{
return;
}
distributionMethod = PartitionMethod(relationId);
distributionColumn = PartitionKey(relationId);
colocationId = TableColocationId(relationId);
relation = relation_open(relationId, ExclusiveLock);
ErrorIfNotSupportedConstraint(relation, distributionMethod,
distributionColumn, colocationId);
relation_close(relation, NoLock);
}
/*
* ErrorIfUnsupportedSeqStmt errors out if the provided create sequence
* statement specifies a distributed table in its OWNED BY clause.

16
src/include/distributed/create_distributed_table.h
View File

@ -1,16 +0,0 @@
/*
* create_distributed_table.h
*
* Created on: Mar 17, 2017
* Author: velioglub
*/
#ifndef SRC_INCLUDE_DISTRIBUTED_CREATE_DISTRIBUTED_TABLE_H_
#define SRC_INCLUDE_DISTRIBUTED_CREATE_DISTRIBUTED_TABLE_H_
extern void ErrorIfNotSupportedConstraint(Relation relation,
char distributionMethod,
Var *distributionColumn,
uint32 colocationId);
#endif /* SRC_INCLUDE_DISTRIBUTED_CREATE_DISTRIBUTED_TABLE_H_ */

7
src/include/distributed/multi_utility.h
View File

@ -25,6 +25,11 @@ extern void multi_ProcessUtility(Node *parsetree, const char *queryString,
ProcessUtilityContext context, ParamListInfo params,
DestReceiver *dest, char *completionTag);
extern void ReplicateGrantStmt(Node *parsetree);
extern void ErrorIfNotSupportedConstraint(Relation relation, char distributionMethod,
Var *distributionColumn, uint32 colocationId);
extern void ErrorIfNotSupportedForeignConstraint(Relation relation,
char distributionMethod,
Var *distributionColumn,
uint32 colocationId);
#endif /* MULTI_UTILITY_H */