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implement ErrorIfUnsupportedAlterAddDropFKeyBetweenReferecenceAndLocalTable

improve-drop-trigger2
Onur Tirtir 2020-03-03 19:21:54 +03:00
parent de8e0a409a
commit 4f0038c4bf
2 changed files with 150 additions and 8 deletions
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150
src/backend/distributed/commands/foreign_constraint.c
View File

@ -100,7 +100,7 @@ ConstraintIsAForeignKeyToReferenceTable(char *constraintName, Oid relationId)
* 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;
* To support foreign constraints in this function, we require that;
* - If referencing and referenced tables are hash-distributed
* - Referencing and referenced tables are co-located.
* - Foreign constraint is defined over distribution column.
@ -114,6 +114,17 @@ ConstraintIsAForeignKeyToReferenceTable(char *constraintName, Oid relationId)
* of the referencing column.
* - If referencing table is a reference table, error out if the referenced
* table is not a reference table.
*
* Note that checks performed in this functions are only done via
* PostprocessAlterTableStmt function. There is another case ,allowed by Citus,
* but being errored out in this function, creating foreign key constraint
* between a reference table and a coordinator local table. The rationale behind
* it is to allow defining foreign keys between coordinator local tables and
* reference tables only via ALTER TABLE ADD CONSTRAINT ... commands. This
* function, prevents upgrading "a local table involved in a foreign key
* constraint with another local table" to a reference table. See also
* ErrorIfUnsupportedAlterAddDropFKeyBetweenReferecenceAndLocalTable and its
* usage.
*/
void
ErrorIfUnsupportedForeignConstraintExists(Relation relation, char referencingDistMethod,
@ -123,11 +134,11 @@ ErrorIfUnsupportedForeignConstraintExists(Relation relation, char referencingDis
ScanKeyData scanKey[1];
int scanKeyCount = 1;
Oid referencingTableId = relation->rd_id;
bool referencingNotReplicated = true;
bool referencingIsCitus = IsCitusTable(referencingTableId);
Oid relationOid = relation->rd_id;
bool relationNotReplicated = true;
bool relationIsCitusTable = IsCitusTable(relationOid);
if (referencingIsCitus)
if (relationIsCitusTable)
{
/* ALTER TABLE command is applied over single replicated table */
referencingNotReplicated = SingleReplicatedTable(referencingTableId);
@ -147,6 +158,7 @@ ErrorIfUnsupportedForeignConstraintExists(Relation relation, char referencingDis
scanKeyCount, scanKey);
HeapTuple heapTuple = systable_getnext(scanDescriptor);
while (HeapTupleIsValid(heapTuple))
{
Form_pg_constraint constraintForm = (Form_pg_constraint) GETSTRUCT(heapTuple);
@ -166,11 +178,12 @@ ErrorIfUnsupportedForeignConstraintExists(Relation relation, char referencingDis
}
Oid referencedTableId = constraintForm->confrelid;
bool referencedIsCitus = IsCitusTable(referencedTableId);
bool referencedIsCitusTable = IsCitusTable(referencedTableId);
bool selfReferencingTable = (referencingTableId == referencedTableId);
if (!referencedIsCitus && !selfReferencingTable)
/* TODO: will remove this block after implementing create table ref_table references local_table */
if (!referencedIsCitusTable && !selfReferencingTable)
{
ereport(ERROR, (errcode(ERRCODE_INVALID_TABLE_DEFINITION),
errmsg("cannot create foreign key constraint"),
@ -219,7 +232,8 @@ ErrorIfUnsupportedForeignConstraintExists(Relation relation, char referencingDis
"since foreign keys from reference tables "
"to distributed tables are not supported"),
errdetail("A reference table can only have reference "
"keys to other reference tables")));
"keys to other reference tables or a local table "
"in coordinator")));
}
/*
@ -395,6 +409,126 @@ ForeignConstraintFindDistKeys(HeapTuple pgConstraintTuple,
}
/*
* ErrorIfUnsupportedAlterAddDropFKeyBetweenReferecenceAndLocalTable runs checks
* related to ALTER ADD / DROP foreign key constraints between local tables and
* reference tables. Note that constraint parameter is not effective DROP foreign
* key commands.
*/
void
ErrorIfUnsupportedAlterAddDropFKeyBetweenReferecenceAndLocalTable(Oid referencingTableOid,
Oid referencedTableOid,
AlterTableType
alterTableType,
Constraint *constraint)
{
Assert((alterTableType == AT_AddConstraint && constraint != NULL) ||
(alterTableType == AT_DropConstraint && constraint == NULL));
Assert(OidIsValid(referencedTableOid) && OidIsValid(referencingTableOid));
bool referencingIsCitusTable = IsCitusTable(referencingTableOid);
char referencingDistMethod = 0;
bool referencingIsReferenceTable = false;
bool referencedIsDistributed = IsDistributedTable(referencedTableOid);
char referencedDistMethod = 0;
bool referencedIsReferenceTable = false;
if (referencingIsCitusTable)
{
referencingDistMethod = PartitionMethod(referencingTableOid);
referencingIsReferenceTable = (referencingDistMethod == DISTRIBUTE_BY_NONE);
}
if (referencedIsDistributed)
{
referencedDistMethod = PartitionMethod(referencedTableOid);
referencedIsReferenceTable = (referencedDistMethod == DISTRIBUTE_BY_NONE);
}
bool fromReferenceTableToLocalTable = referencingIsReferenceTable &&
!referencedIsCitusTable;
bool fromLocalTableToReferenceTable = !referencingIsCitusTable &&
referencedIsReferenceTable;
if (!fromLocalTableToReferenceTable && !fromLocalTableToReferenceTable)
{
return;
}
/* reference table <> local table */
if (alterTableType == AT_AddConstraint)
{
/*
* As defining a foreign key constraint between two tables requires
* to execute a join query between those two tables (a reference
* table and a local table at this point), we would already error
* out in CitusExecutorRun function as Citus does not support joining
* local tables and reference tables in transaction blocks yet.
* However, both to early error out and to give a more appropriate
* error message, we will throw the below error.
*/
if (IsMultiStatementTransaction())
{
ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg(
"cannot define foreign key constraint between a local table "
"and a reference table in a transaction block, udf block, or "
"distributed CTE subquery")));
}
/*
* We only support RESTRICT or NO ACTION behaviour for "ALTER TABLE
* reference_table ADD CONSTRAINT fkey FOREIGN KEY REFERENCES
* local_table ON DELETE / UPDATE" commands
*/
bool onUpdateNoActionOrRestrict = (constraint->fk_upd_action ==
FKCONSTR_ACTION_NOACTION ||
constraint->fk_upd_action ==
FKCONSTR_ACTION_RESTRICT);
bool onDeleteNoActionOrRestrict = (constraint->fk_del_action ==
FKCONSTR_ACTION_NOACTION ||
constraint->fk_del_action ==
FKCONSTR_ACTION_RESTRICT);
if (fromReferenceTableToLocalTable && (!onUpdateNoActionOrRestrict ||
!onDeleteNoActionOrRestrict))
{
ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg(
"cannot create foreign key constraint"),
errdetail(
"Foreign key constraints from reference tables to coordinator "
"local tables can only enforce RESTRICT or NO ACTION behaviour "
"ON DELETE / UPDATE")));
}
}
if (alterTableType == AT_AddConstraint || alterTableType == AT_DropConstraint)
{
/*
* Check if we are in the coordinator and coordinator can have reference
* table placements
*/
if (!CanUseCoordinatorLocalTablesWithReferenceTables())
{
ereport(ERROR, (errcode(ERRCODE_INVALID_TABLE_DEFINITION),
errmsg(
"cannot ADD/DROP foreign key constraint"),
errdetail(
"Referenced table must be a distributed table"
" or a reference table or a local table in coordinator."),
errhint(
"To ADD/DROP foreign constraint between reference tables "
"and coordinator local tables, consider adding coordinator "
"to pg_dist_node as well.")));
}
}
}
/*
* ColumnAppearsInForeignKeyToReferenceTable checks if there is a foreign key
* constraint from/to a reference table on the given column. We iterate

8
src/include/distributed/commands.h
View File

@ -99,6 +99,14 @@ extern void ErrorIfUnsupportedForeignConstraintExists(Relation relation,
char distributionMethod,
Var *distributionColumn,
uint32 colocationId);
extern void ErrorIfUnsupportedAlterAddDropFKeyBetweenReferecenceAndLocalTable(Oid
referencingTableOid,
Oid
referencedTableOid,
AlterTableType
alterTableType,
Constraint *
constraint);
extern bool ColumnAppearsInForeignKeyToReferenceTable(char *columnName, Oid
relationId);
extern List * GetTableForeignConstraintCommands(Oid relationId);