mirror of https://github.com/citusdata/citus.git
change ErrorIfUnsupportedForeignConstraintExists function to use in two-way
Onur Tirtir
parent
ef1447e360
commit
8cec216af1
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@ -114,7 +114,7 @@ ConstraintIsAForeignKeyToReferenceTable(char *constraintName, Oid relationId)
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* of the referencing column.
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* - If referencing table is a reference table, error out if the referenced
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* table is not a reference table.
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*
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*
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* Note that checks performed in this functions are only done via
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* PostprocessAlterTableStmt function. There is another case ,allowed by Citus,
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* but being errored out in this function, creating foreign key constraint
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@ -127,34 +127,35 @@ ConstraintIsAForeignKeyToReferenceTable(char *constraintName, Oid relationId)
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* usage.
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*/
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void
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ErrorIfUnsupportedForeignConstraintExists(Relation relation, char referencingDistMethod,
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Var *referencingDistKey,
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uint32 referencingColocationId)
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ErrorIfUnsupportedForeignConstraintExists(Relation relation, char distributionMethod,
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Var *distributionColumn,
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uint32 colocationId)
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{
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ScanKeyData scanKey[1];
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int scanKeyCount = 1;
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Oid relationOid = relation->rd_id;
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bool relationNotReplicated = true;
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bool relationIsCitusTable = IsCitusTable(relationOid);
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bool relationIsReferenceTable = (distributionMethod == DISTRIBUTE_BY_NONE);
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bool relationNotReplicated = true;
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if (relationIsCitusTable)
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{
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/* ALTER TABLE command is applied over single replicated table */
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referencingNotReplicated = SingleReplicatedTable(referencingTableId);
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relationNotReplicated = SingleReplicatedTable(relationOid);
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}
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else
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{
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/* Creating single replicated table with foreign constraint */
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referencingNotReplicated = (ShardReplicationFactor == 1);
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relationNotReplicated = (ShardReplicationFactor == 1);
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}
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Relation pgConstraint = heap_open(ConstraintRelationId, AccessShareLock);
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ScanKeyInit(&scanKey[0], Anum_pg_constraint_conrelid, BTEqualStrategyNumber, F_OIDEQ,
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relation->rd_id);
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ScanKeyInit(&scanKey[0], Anum_pg_constraint_contype, BTEqualStrategyNumber, F_CHAREQ,
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CharGetDatum(CONSTRAINT_FOREIGN));
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SysScanDesc scanDescriptor = systable_beginscan(pgConstraint,
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ConstraintRelidTypidNameIndexId,
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true, NULL,
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InvalidOid,
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false, NULL,
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scanKeyCount, scanKey);
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HeapTuple heapTuple = systable_getnext(scanDescriptor);
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@ -163,182 +164,249 @@ ErrorIfUnsupportedForeignConstraintExists(Relation relation, char referencingDis
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{
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Form_pg_constraint constraintForm = (Form_pg_constraint) GETSTRUCT(heapTuple);
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int referencingAttrIndex = -1;
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char referencedDistMethod = 0;
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Var *referencedDistKey = NULL;
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int referencedAttrIndex = -1;
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uint32 referencedColocationId = INVALID_COLOCATION_ID;
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/* not a foreign key constraint, skip to next one */
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if (constraintForm->contype != CONSTRAINT_FOREIGN)
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if (constraintForm->conrelid == relationOid)
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{
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heapTuple = systable_getnext(scanDescriptor);
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continue;
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}
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/* alias variables from the referencing table perspective */
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Oid referencingTableId = relationOid;
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char referencingDistMethod = distributionMethod;
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Var *referencingDistKey = distributionColumn;
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uint32 referencingColocationId = colocationId;
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Oid referencedTableId = constraintForm->confrelid;
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bool referencedIsCitusTable = IsCitusTable(referencedTableId);
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bool referencingIsCitusTable = relationIsCitusTable;
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bool referencingIsReferenceTable = relationIsReferenceTable;
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bool referencingNotReplicated = relationNotReplicated;
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bool selfReferencingTable = (referencingTableId == referencedTableId);
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char referencedDistMethod = 0;
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Var *referencedDistKey = NULL;
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uint32 referencedColocationId = INVALID_COLOCATION_ID;
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/* TODO: will remove this block after implementing create table ref_table references local_table */
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if (!referencedIsCitusTable && !selfReferencingTable)
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{
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ereport(ERROR, (errcode(ERRCODE_INVALID_TABLE_DEFINITION),
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errmsg("cannot create foreign key constraint"),
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errdetail("Referenced table must be a distributed table"
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" or a reference table.")));
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}
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Oid referencedTableId = constraintForm->confrelid;
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bool referencedIsCitusTable = IsCitusTable(referencedTableId);
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int referencedAttrIndex = -1;
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/* set referenced table related variables here if table is referencing itself */
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bool selfReferencingTable = (referencingTableId == referencedTableId);
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if (!selfReferencingTable)
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{
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referencedDistMethod = PartitionMethod(referencedTableId);
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referencedDistKey = (referencedDistMethod == DISTRIBUTE_BY_NONE) ?
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NULL :
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DistPartitionKey(referencedTableId);
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referencedColocationId = TableColocationId(referencedTableId);
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}
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else
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{
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referencedDistMethod = referencingDistMethod;
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referencedDistKey = referencingDistKey;
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referencedColocationId = referencingColocationId;
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}
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bool referencingIsReferenceTable = (referencingDistMethod == DISTRIBUTE_BY_NONE);
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bool referencedIsReferenceTable = (referencedDistMethod == DISTRIBUTE_BY_NONE);
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/*
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* We support foreign keys between reference tables. No more checks
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* are necessary.
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*/
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if (referencingIsReferenceTable && referencedIsReferenceTable)
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{
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heapTuple = systable_getnext(scanDescriptor);
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continue;
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}
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/*
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* Foreign keys from reference tables to distributed tables are not
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* supported.
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*/
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if (referencingIsReferenceTable && !referencedIsReferenceTable)
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{
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ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
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errmsg("cannot create foreign key constraint "
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"since foreign keys from reference tables "
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"to distributed tables are not supported"),
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errdetail("A reference table can only have reference "
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"keys to other reference tables or a local table "
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"in coordinator")));
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}
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/*
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* To enforce foreign constraints, tables must be co-located unless a
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* reference table is referenced.
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*/
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if (referencingColocationId == INVALID_COLOCATION_ID ||
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(referencingColocationId != referencedColocationId &&
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!referencedIsReferenceTable))
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{
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ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
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errmsg("cannot create foreign key constraint since "
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"relations are not colocated or not referencing "
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"a reference table"),
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errdetail(
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"A distributed table can only have foreign keys "
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"if it is referencing another colocated hash "
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"distributed table or a reference table")));
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}
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ForeignConstraintFindDistKeys(heapTuple,
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referencingDistKey,
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referencedDistKey,
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&referencingAttrIndex,
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&referencedAttrIndex);
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bool referencingColumnsIncludeDistKey = (referencingAttrIndex != -1);
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bool foreignConstraintOnDistKey =
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(referencingColumnsIncludeDistKey && referencingAttrIndex ==
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referencedAttrIndex);
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/*
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* If columns in the foreign key includes the distribution key from the
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* referencing side, we do not allow update/delete operations through
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* foreign key constraints (e.g. ... ON UPDATE SET NULL)
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*/
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if (referencingColumnsIncludeDistKey)
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{
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/*
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* ON DELETE SET NULL and ON DELETE SET DEFAULT is not supported. Because we do
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* not want to set partition column to NULL or default value.
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*/
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if (constraintForm->confdeltype == FKCONSTR_ACTION_SETNULL ||
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constraintForm->confdeltype == FKCONSTR_ACTION_SETDEFAULT)
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/* TODO: will remove this block after implementing create table ref_table references local_table */
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if (!referencedIsCitusTable && !selfReferencingTable)
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{
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ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
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ereport(ERROR, (errcode(ERRCODE_INVALID_TABLE_DEFINITION),
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errmsg("cannot create foreign key constraint"),
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errdetail("SET NULL or SET DEFAULT is not supported"
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" in ON DELETE operation when distribution "
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"key is included in the foreign key constraint")));
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errdetail("Referenced table must be a distributed table"
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" or a reference table.")));
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}
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/* set referenced table related variables here if table is referencing itself */
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if (!selfReferencingTable)
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{
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if (referencedIsCitusTable)
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{
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referencedDistMethod = PartitionMethod(referencedTableId);
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referencedDistKey = (referencedDistMethod == DISTRIBUTE_BY_NONE) ?
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NULL :
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DistPartitionKey(referencedTableId);
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referencedColocationId = TableColocationId(referencedTableId);
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}
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}
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else
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{
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referencedDistMethod = referencingDistMethod;
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referencedDistKey = referencingDistKey;
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referencedColocationId = referencingColocationId;
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}
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bool referencedIsReferenceTable = (referencedDistMethod ==
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DISTRIBUTE_BY_NONE);
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/* foreign key constraint between reference tables */
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if (referencingIsReferenceTable && referencedIsReferenceTable)
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{
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/*
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* We support foreign keys between reference tables. No more checks
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* are necessary.
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*/
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heapTuple = systable_getnext(scanDescriptor);
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continue;
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}
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/* foreign key constraint from a reference table to a local table */
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if (referencingIsReferenceTable && !referencedIsCitusTable)
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{
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/*
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* Upgrading "a local table having a foreign key constraint to another
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* local table" to a reference table is not supported.
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*/
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ereport(ERROR, (errcode(ERRCODE_INVALID_TABLE_DEFINITION),
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errmsg("cannot create foreign key constraint"),
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errdetail(
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"Local table having a foreign key constraint to another "
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"local table cannot be upgraded to a reference table"),
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errhint(
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"To define foreign key constraint from a reference table to a "
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"local table, use ALTER TABLE ADD CONSTRAINT ... command after "
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"creating the reference table without a foreign key")));
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}
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/* distributed table to local table */
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if (!referencingIsReferenceTable && referencingIsCitusTable &&
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!referencedIsCitusTable)
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{
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ereport(ERROR, (errcode(ERRCODE_INVALID_TABLE_DEFINITION),
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errmsg("cannot create foreign key constraint"),
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errdetail(
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"Foreign keys from distributed tables to local tables are not supported")));
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}
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if (referencingIsReferenceTable && referencedIsCitusTable &&
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!referencedIsReferenceTable)
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{
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/*
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* Foreign keys from reference tables to distributed tables are not
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* supported.
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*/
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ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
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errmsg("cannot create foreign key constraint "
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"since foreign keys from reference tables "
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"to distributed tables are not supported"),
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errdetail("A reference table can only have reference "
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"keys to other reference tables or a local table "
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"in coordinator")));
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}
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/*
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* ON UPDATE SET NULL, ON UPDATE SET DEFAULT and UPDATE CASCADE is not supported.
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* Because we do not want to set partition column to NULL or default value. Also
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* cascading update operation would require re-partitioning. Updating partition
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* column value is not allowed anyway even outside of foreign key concept.
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* To enforce foreign constraints, tables must be co-located unless a
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* reference table is referenced.
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*/
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if (constraintForm->confupdtype == FKCONSTR_ACTION_SETNULL ||
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constraintForm->confupdtype == FKCONSTR_ACTION_SETDEFAULT ||
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constraintForm->confupdtype == FKCONSTR_ACTION_CASCADE)
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if (referencingColocationId == INVALID_COLOCATION_ID ||
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(referencingColocationId != referencedColocationId &&
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!referencedIsReferenceTable))
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{
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ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
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errmsg("cannot create foreign key constraint since "
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"relations are not colocated or not referencing "
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"a reference table"),
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errdetail(
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"A distributed table can only have foreign keys "
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"if it is referencing another colocated hash "
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"distributed table or a reference table")));
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}
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int referencingAttrIndex = -1;
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ForeignConstraintFindDistKeys(heapTuple,
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referencingDistKey,
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referencedDistKey,
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&referencingAttrIndex,
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&referencedAttrIndex);
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bool referencingColumnsIncludeDistKey = (referencingAttrIndex != -1);
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bool foreignConstraintOnDistKey =
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(referencingColumnsIncludeDistKey && referencingAttrIndex ==
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referencedAttrIndex);
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/*
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* If columns in the foreign key includes the distribution key from the
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* referencing side, we do not allow update/delete operations through
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* foreign key constraints (e.g. ... ON UPDATE SET NULL)
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*/
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if (referencingColumnsIncludeDistKey)
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{
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/*
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* ON DELETE SET NULL and ON DELETE SET DEFAULT is not supported. Because we do
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* not want to set partition column to NULL or default value.
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*/
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if (constraintForm->confdeltype == FKCONSTR_ACTION_SETNULL ||
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constraintForm->confdeltype == FKCONSTR_ACTION_SETDEFAULT)
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{
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ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
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errmsg("cannot create foreign key constraint"),
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errdetail("SET NULL or SET DEFAULT is not supported"
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" in ON DELETE operation when distribution "
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"key is included in the foreign key constraint")));
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}
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/*
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* ON UPDATE SET NULL, ON UPDATE SET DEFAULT and UPDATE CASCADE is not supported.
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* Because we do not want to set partition column to NULL or default value. Also
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* cascading update operation would require re-partitioning. Updating partition
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* column value is not allowed anyway even outside of foreign key concept.
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*/
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if (constraintForm->confupdtype == FKCONSTR_ACTION_SETNULL ||
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constraintForm->confupdtype == FKCONSTR_ACTION_SETDEFAULT ||
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constraintForm->confupdtype == FKCONSTR_ACTION_CASCADE)
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{
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ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
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errmsg("cannot create foreign key constraint"),
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errdetail("SET NULL, SET DEFAULT or CASCADE is not "
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"supported in ON UPDATE operation when "
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"distribution key included in the foreign "
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"constraint.")));
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}
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}
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/*
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* if tables are hash-distributed and colocated, we need to make sure that
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* the distribution key is included in foreign constraint.
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*/
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if (!referencedIsReferenceTable && !foreignConstraintOnDistKey)
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{
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ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
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errmsg("cannot create foreign key constraint"),
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errdetail("SET NULL, SET DEFAULT or CASCADE is not "
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"supported in ON UPDATE operation when "
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"distribution key included in the foreign "
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"constraint.")));
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errdetail("Foreign keys are supported in two cases, "
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"either in between two colocated tables including "
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"partition column in the same ordinal in the both "
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"tables or from distributed to reference tables")));
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}
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}
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/*
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* if tables are hash-distributed and colocated, we need to make sure that
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* the distribution key is included in foreign constraint.
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*/
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if (!referencedIsReferenceTable && !foreignConstraintOnDistKey)
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{
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ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
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errmsg("cannot create foreign key constraint"),
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errdetail("Foreign keys are supported in two cases, "
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"either in between two colocated tables including "
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"partition column in the same ordinal in the both "
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"tables or from distributed to reference tables")));
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}
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/*
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* We do not allow to create foreign constraints if shard replication factor is
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* greater than 1. Because in our current design, multiple replicas may cause
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* locking problems and inconsistent shard contents.
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*
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* Note that we allow referenced table to be a reference table (e.g., not a
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* single replicated table). This is allowed since (a) we are sure that
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* placements always be in the same state (b) executors are aware of reference
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* tables and handle concurrency related issues accordingly.
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*/
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if (!referencingNotReplicated)
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{
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ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
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errmsg("cannot create foreign key constraint"),
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errdetail("Citus Community Edition currently supports "
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"foreign key constraints only for "
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"\"citus.shard_replication_factor = 1\"."),
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errhint("Please change \"citus.shard_replication_factor to "
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/*
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* We do not allow to create foreign constraints if shard replication factor is
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* greater than 1. Because in our current design, multiple replicas may cause
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* locking problems and inconsistent shard contents.
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*
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* Note that we allow referenced table to be a reference table (e.g., not a
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* single replicated table). This is allowed since (a) we are sure that
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* placements always be in the same state (b) executors are aware of reference
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* tables and handle concurrency related issues accordingly.
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*/
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if (!referencingNotReplicated)
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{
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ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
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errmsg("cannot create foreign key constraint"),
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errdetail("Citus Community Edition currently supports "
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"foreign key constraints only for "
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"\"citus.shard_replication_factor = 1\"."),
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errhint(
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"Please change \"citus.shard_replication_factor to "
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"1\". To learn more about using foreign keys with "
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"other replication factors, please contact us at "
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"https://citusdata.com/about/contact_us.")));
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}
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}
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else if (constraintForm->confrelid == relationOid)
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{
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/* alias variables from the referenced table perspective */
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bool referencedIsReferenceTable = relationIsReferenceTable;
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Oid referencingTableId = constraintForm->conrelid;
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bool referencingIsCitusTable = IsCitusTable(referencingTableId);
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/* foreign key constraint from a local table to a reference table */
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if (!referencingIsCitusTable && referencedIsReferenceTable)
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{
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/*
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* Upgrading "a local table referenced by another local table"
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* to a reference table is supported, but not encouraged.
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*/
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ereport(WARNING, (errcode(ERRCODE_INVALID_TABLE_DEFINITION),
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errmsg(
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"should not create foreign key constraint in this way"),
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errdetail(
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"Local table referenced by another local table should not "
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"be upgraded to a reference table"),
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errhint(
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"To define foreign key constraint from a local table to a "
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"reference table properly, use ALTER TABLE ADD CONSTRAINT ... "
|
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"command after creating the reference table without a foreign key")));
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}
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}
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heapTuple = systable_getnext(scanDescriptor);
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|
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@ -430,7 +498,7 @@ ErrorIfUnsupportedAlterAddDropFKeyBetweenReferecenceAndLocalTable(Oid referencin
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char referencingDistMethod = 0;
|
||||
bool referencingIsReferenceTable = false;
|
||||
|
||||
bool referencedIsDistributed = IsDistributedTable(referencedTableOid);
|
||||
bool referencedIsCitusTable = IsCitusTable(referencedTableOid);
|
||||
char referencedDistMethod = 0;
|
||||
bool referencedIsReferenceTable = false;
|
||||
|
||||
|
|
@ -440,7 +508,7 @@ ErrorIfUnsupportedAlterAddDropFKeyBetweenReferecenceAndLocalTable(Oid referencin
|
|||
referencingIsReferenceTable = (referencingDistMethod == DISTRIBUTE_BY_NONE);
|
||||
}
|
||||
|
||||
if (referencedIsDistributed)
|
||||
if (referencedIsCitusTable)
|
||||
{
|
||||
referencedDistMethod = PartitionMethod(referencedTableOid);
|
||||
referencedIsReferenceTable = (referencedDistMethod == DISTRIBUTE_BY_NONE);
|
||||
|
|
|
|||
Loading…
Reference in New Issue