pg_attrdef.h File Reference

#include "catalog/genbki.h"
#include "catalog/objectaddress.h"
#include "catalog/pg_attrdef_d.h"

Include dependency graph for pg_attrdef.h:

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Go to the source code of this file.

Typedefs
typedef FormData_pg_attrdef *	Form_pg_attrdef

Functions
	CATALOG (pg_attrdef, 2604, AttrDefaultRelationId)
	DECLARE_TOAST (pg_attrdef, 2830, 2831)
	DECLARE_UNIQUE_INDEX (pg_attrdef_adrelid_adnum_index, 2656, AttrDefaultIndexId, pg_attrdef, btree(adrelid oid_ops, adnum int2_ops))
	DECLARE_UNIQUE_INDEX_PKEY (pg_attrdef_oid_index, 2657, AttrDefaultOidIndexId, pg_attrdef, btree(oid oid_ops))
	DECLARE_FOREIGN_KEY ((adrelid, adnum), pg_attribute,(attrelid, attnum))
Oid	StoreAttrDefault (Relation rel, AttrNumber attnum, Node *expr, bool is_internal, bool add_column_mode)
void	RemoveAttrDefault (Oid relid, AttrNumber attnum, DropBehavior behavior, bool complain, bool internal)
void	RemoveAttrDefaultById (Oid attrdefId)
Oid	GetAttrDefaultOid (Oid relid, AttrNumber attnum)
ObjectAddress	GetAttrDefaultColumnAddress (Oid attrdefoid)

Variables
	FormData_pg_attrdef

Typedef Documentation

Form_pg_attrdef

typedef FormData_pg_attrdef* Form_pg_attrdef

Definition at line 49 of file pg_attrdef.h.

Function Documentation

CATALOG()

CATALOG	(	pg_attrdef	,
		2604	,
		AttrDefaultRelationId
	)

Definition at line 30 of file pg_attrdef.h.

{
    Oid         oid;            /* oid */
 
    Oid         adrelid BKI_LOOKUP(pg_class);   /* OID of table containing
                                                 * attribute */
    int16       adnum;          /* attnum of attribute */
 
#ifdef CATALOG_VARLEN           /* variable-length fields start here */
    pg_node_tree adbin BKI_FORCE_NOT_NULL;  /* nodeToString representation of
                                             * default */
#endif
} FormData_pg_attrdef;

References BKI_FORCE_NOT_NULL, and BKI_LOOKUP.

DECLARE_FOREIGN_KEY()

DECLARE_FOREIGN_KEY	(	(adrelid, adnum)	,
		pg_attribute	,
		(attrelid, attnum)
	)

DECLARE_TOAST()

DECLARE_TOAST	(	pg_attrdef	,
		2830	,
		2831
	)

DECLARE_UNIQUE_INDEX()

DECLARE_UNIQUE_INDEX	(	pg_attrdef_adrelid_adnum_index	,
		2656	,
		AttrDefaultIndexId	,
		pg_attrdef	,
		btree(adrelid oid_ops, adnum int2_ops)
	)

DECLARE_UNIQUE_INDEX_PKEY()

DECLARE_UNIQUE_INDEX_PKEY	(	pg_attrdef_oid_index	,
		2657	,
		AttrDefaultOidIndexId	,
		pg_attrdef	,
		btree(oid oid_ops)
	)

GetAttrDefaultColumnAddress()

ObjectAddress GetAttrDefaultColumnAddress

(

Oid

attrdefoid

)

Definition at line 381 of file pg_attrdef.c.

{
    ObjectAddress result = InvalidObjectAddress;
    Relation    attrdef;
    ScanKeyData skey[1];
    SysScanDesc scan;
    HeapTuple   tup;
 
    attrdef = table_open(AttrDefaultRelationId, AccessShareLock);
    ScanKeyInit(&skey[0],
                Anum_pg_attrdef_oid,
                BTEqualStrategyNumber, F_OIDEQ,
                ObjectIdGetDatum(attrdefoid));
    scan = systable_beginscan(attrdef, AttrDefaultOidIndexId, true,
                              NULL, 1, skey);
 
    if (HeapTupleIsValid(tup = systable_getnext(scan)))
    {
        Form_pg_attrdef atdform = (Form_pg_attrdef) GETSTRUCT(tup);
 
        result.classId = RelationRelationId;
        result.objectId = atdform->adrelid;
        result.objectSubId = atdform->adnum;
    }
 
    systable_endscan(scan);
    table_close(attrdef, AccessShareLock);
 
    return result;
}

References AccessShareLock, BTEqualStrategyNumber, ObjectAddress::classId, GETSTRUCT, HeapTupleIsValid, InvalidObjectAddress, ObjectAddress::objectId, ObjectIdGetDatum(), ObjectAddress::objectSubId, ScanKeyInit(), systable_beginscan(), systable_endscan(), systable_getnext(), table_close(), and table_open().

Referenced by getObjectDescription(), getObjectIdentityParts(), and RememberAllDependentForRebuilding().

GetAttrDefaultOid()

Oid GetAttrDefaultOid	(	Oid	relid,
		AttrNumber	attnum
	)

Definition at line 339 of file pg_attrdef.c.

{
    Oid         result = InvalidOid;
    Relation    attrdef;
    ScanKeyData keys[2];
    SysScanDesc scan;
    HeapTuple   tup;
 
    attrdef = table_open(AttrDefaultRelationId, AccessShareLock);
    ScanKeyInit(&keys[0],
                Anum_pg_attrdef_adrelid,
                BTEqualStrategyNumber,
                F_OIDEQ,
                ObjectIdGetDatum(relid));
    ScanKeyInit(&keys[1],
                Anum_pg_attrdef_adnum,
                BTEqualStrategyNumber,
                F_INT2EQ,
                Int16GetDatum(attnum));
    scan = systable_beginscan(attrdef, AttrDefaultIndexId, true,
                              NULL, 2, keys);
 
    if (HeapTupleIsValid(tup = systable_getnext(scan)))
    {
        Form_pg_attrdef atdform = (Form_pg_attrdef) GETSTRUCT(tup);
 
        result = atdform->oid;
    }
 
    systable_endscan(scan);
    table_close(attrdef, AccessShareLock);
 
    return result;
}

References AccessShareLock, attnum, BTEqualStrategyNumber, GETSTRUCT, HeapTupleIsValid, Int16GetDatum(), InvalidOid, ObjectIdGetDatum(), ScanKeyInit(), systable_beginscan(), systable_endscan(), systable_getnext(), table_close(), and table_open().

Referenced by ATExecAlterColumnType(), ATExecDropExpression(), ATExecSetExpression(), and get_object_address_attrdef().

RemoveAttrDefault()

void RemoveAttrDefault	(	Oid	relid,
		AttrNumber	attnum,
		DropBehavior	behavior,
		bool	complain,
		bool	internal
	)

Definition at line 213 of file pg_attrdef.c.

{
    Relation    attrdef_rel;
    ScanKeyData scankeys[2];
    SysScanDesc scan;
    HeapTuple   tuple;
    bool        found = false;
 
    attrdef_rel = table_open(AttrDefaultRelationId, RowExclusiveLock);
 
    ScanKeyInit(&scankeys[0],
                Anum_pg_attrdef_adrelid,
                BTEqualStrategyNumber, F_OIDEQ,
                ObjectIdGetDatum(relid));
    ScanKeyInit(&scankeys[1],
                Anum_pg_attrdef_adnum,
                BTEqualStrategyNumber, F_INT2EQ,
                Int16GetDatum(attnum));
 
    scan = systable_beginscan(attrdef_rel, AttrDefaultIndexId, true,
                              NULL, 2, scankeys);
 
    /* There should be at most one matching tuple, but we loop anyway */
    while (HeapTupleIsValid(tuple = systable_getnext(scan)))
    {
        ObjectAddress object;
        Form_pg_attrdef attrtuple = (Form_pg_attrdef) GETSTRUCT(tuple);
 
        object.classId = AttrDefaultRelationId;
        object.objectId = attrtuple->oid;
        object.objectSubId = 0;
 
        performDeletion(&object, behavior,
                        internal ? PERFORM_DELETION_INTERNAL : 0);
 
        found = true;
    }
 
    systable_endscan(scan);
    table_close(attrdef_rel, RowExclusiveLock);
 
    if (complain && !found)
        elog(ERROR, "could not find attrdef tuple for relation %u attnum %d",
             relid, attnum);
}

References attnum, BTEqualStrategyNumber, elog, ERROR, GETSTRUCT, HeapTupleIsValid, Int16GetDatum(), ObjectIdGetDatum(), PERFORM_DELETION_INTERNAL, performDeletion(), RowExclusiveLock, ScanKeyInit(), systable_beginscan(), systable_endscan(), systable_getnext(), table_close(), and table_open().

Referenced by ATExecAlterColumnType(), ATExecColumnDefault(), ATExecCookedColumnDefault(), ATExecDropExpression(), and ATExecSetExpression().

RemoveAttrDefaultById()

void RemoveAttrDefaultById

(

Oid

attrdefId

)

Definition at line 268 of file pg_attrdef.c.

{
    Relation    attrdef_rel;
    Relation    attr_rel;
    Relation    myrel;
    ScanKeyData scankeys[1];
    SysScanDesc scan;
    HeapTuple   tuple;
    Oid         myrelid;
    AttrNumber  myattnum;
 
    /* Grab an appropriate lock on the pg_attrdef relation */
    attrdef_rel = table_open(AttrDefaultRelationId, RowExclusiveLock);
 
    /* Find the pg_attrdef tuple */
    ScanKeyInit(&scankeys[0],
                Anum_pg_attrdef_oid,
                BTEqualStrategyNumber, F_OIDEQ,
                ObjectIdGetDatum(attrdefId));
 
    scan = systable_beginscan(attrdef_rel, AttrDefaultOidIndexId, true,
                              NULL, 1, scankeys);
 
    tuple = systable_getnext(scan);
    if (!HeapTupleIsValid(tuple))
        elog(ERROR, "could not find tuple for attrdef %u", attrdefId);
 
    myrelid = ((Form_pg_attrdef) GETSTRUCT(tuple))->adrelid;
    myattnum = ((Form_pg_attrdef) GETSTRUCT(tuple))->adnum;
 
    /* Get an exclusive lock on the relation owning the attribute */
    myrel = relation_open(myrelid, AccessExclusiveLock);
 
    /* Now we can delete the pg_attrdef row */
    CatalogTupleDelete(attrdef_rel, &tuple->t_self);
 
    systable_endscan(scan);
    table_close(attrdef_rel, RowExclusiveLock);
 
    /* Fix the pg_attribute row */
    attr_rel = table_open(AttributeRelationId, RowExclusiveLock);
 
    tuple = SearchSysCacheCopy2(ATTNUM,
                                ObjectIdGetDatum(myrelid),
                                Int16GetDatum(myattnum));
    if (!HeapTupleIsValid(tuple))   /* shouldn't happen */
        elog(ERROR, "cache lookup failed for attribute %d of relation %u",
             myattnum, myrelid);
 
    ((Form_pg_attribute) GETSTRUCT(tuple))->atthasdef = false;
 
    CatalogTupleUpdate(attr_rel, &tuple->t_self, tuple);
 
    /*
     * Our update of the pg_attribute row will force a relcache rebuild, so
     * there's nothing else to do here.
     */
    table_close(attr_rel, RowExclusiveLock);
 
    /* Keep lock on attribute's rel until end of xact */
    relation_close(myrel, NoLock);
}

References AccessExclusiveLock, BTEqualStrategyNumber, CatalogTupleDelete(), CatalogTupleUpdate(), elog, ERROR, GETSTRUCT, HeapTupleIsValid, Int16GetDatum(), NoLock, ObjectIdGetDatum(), relation_close(), relation_open(), RowExclusiveLock, ScanKeyInit(), SearchSysCacheCopy2, systable_beginscan(), systable_endscan(), systable_getnext(), HeapTupleData::t_self, table_close(), and table_open().

Referenced by doDeletion().

StoreAttrDefault()

Oid StoreAttrDefault	(	Relation	rel,
		AttrNumber	attnum,
		Node *	expr,
		bool	is_internal,
		bool	add_column_mode
	)

Definition at line 46 of file pg_attrdef.c.

{
    char       *adbin;
    Relation    adrel;
    HeapTuple   tuple;
    Datum       values[4];
    static bool nulls[4] = {false, false, false, false};
    Relation    attrrel;
    HeapTuple   atttup;
    Form_pg_attribute attStruct;
    char        attgenerated;
    Oid         attrdefOid;
    ObjectAddress colobject,
                defobject;
 
    adrel = table_open(AttrDefaultRelationId, RowExclusiveLock);
 
    /*
     * Flatten expression to string form for storage.
     */
    adbin = nodeToString(expr);
 
    /*
     * Make the pg_attrdef entry.
     */
    attrdefOid = GetNewOidWithIndex(adrel, AttrDefaultOidIndexId,
                                    Anum_pg_attrdef_oid);
    values[Anum_pg_attrdef_oid - 1] = ObjectIdGetDatum(attrdefOid);
    values[Anum_pg_attrdef_adrelid - 1] = RelationGetRelid(rel);
    values[Anum_pg_attrdef_adnum - 1] = attnum;
    values[Anum_pg_attrdef_adbin - 1] = CStringGetTextDatum(adbin);
 
    tuple = heap_form_tuple(adrel->rd_att, values, nulls);
    CatalogTupleInsert(adrel, tuple);
 
    defobject.classId = AttrDefaultRelationId;
    defobject.objectId = attrdefOid;
    defobject.objectSubId = 0;
 
    table_close(adrel, RowExclusiveLock);
 
    /* now can free some of the stuff allocated above */
    pfree(DatumGetPointer(values[Anum_pg_attrdef_adbin - 1]));
    heap_freetuple(tuple);
    pfree(adbin);
 
    /*
     * Update the pg_attribute entry for the column to show that a default
     * exists.
     */
    attrrel = table_open(AttributeRelationId, RowExclusiveLock);
    atttup = SearchSysCacheCopy2(ATTNUM,
                                 ObjectIdGetDatum(RelationGetRelid(rel)),
                                 Int16GetDatum(attnum));
    if (!HeapTupleIsValid(atttup))
        elog(ERROR, "cache lookup failed for attribute %d of relation %u",
             attnum, RelationGetRelid(rel));
    attStruct = (Form_pg_attribute) GETSTRUCT(atttup);
    attgenerated = attStruct->attgenerated;
    if (!attStruct->atthasdef)
    {
        Form_pg_attribute defAttStruct;
 
        ExprState  *exprState;
        Expr       *expr2 = (Expr *) expr;
        EState     *estate = NULL;
        ExprContext *econtext;
        Datum       valuesAtt[Natts_pg_attribute] = {0};
        bool        nullsAtt[Natts_pg_attribute] = {0};
        bool        replacesAtt[Natts_pg_attribute] = {0};
        Datum       missingval = (Datum) 0;
        bool        missingIsNull = true;
 
        valuesAtt[Anum_pg_attribute_atthasdef - 1] = true;
        replacesAtt[Anum_pg_attribute_atthasdef - 1] = true;
 
        if (rel->rd_rel->relkind == RELKIND_RELATION && add_column_mode &&
            !attgenerated)
        {
            expr2 = expression_planner(expr2);
            estate = CreateExecutorState();
            exprState = ExecPrepareExpr(expr2, estate);
            econtext = GetPerTupleExprContext(estate);
 
            missingval = ExecEvalExpr(exprState, econtext,
                                      &missingIsNull);
 
            FreeExecutorState(estate);
 
            defAttStruct = TupleDescAttr(rel->rd_att, attnum - 1);
 
            if (missingIsNull)
            {
                /* if the default evaluates to NULL, just store a NULL array */
                missingval = (Datum) 0;
            }
            else
            {
                /* otherwise make a one-element array of the value */
                missingval = PointerGetDatum(construct_array(&missingval,
                                                             1,
                                                             defAttStruct->atttypid,
                                                             defAttStruct->attlen,
                                                             defAttStruct->attbyval,
                                                             defAttStruct->attalign));
            }
 
            valuesAtt[Anum_pg_attribute_atthasmissing - 1] = !missingIsNull;
            replacesAtt[Anum_pg_attribute_atthasmissing - 1] = true;
            valuesAtt[Anum_pg_attribute_attmissingval - 1] = missingval;
            replacesAtt[Anum_pg_attribute_attmissingval - 1] = true;
            nullsAtt[Anum_pg_attribute_attmissingval - 1] = missingIsNull;
        }
        atttup = heap_modify_tuple(atttup, RelationGetDescr(attrrel),
                                   valuesAtt, nullsAtt, replacesAtt);
 
        CatalogTupleUpdate(attrrel, &atttup->t_self, atttup);
 
        if (!missingIsNull)
            pfree(DatumGetPointer(missingval));
    }
    table_close(attrrel, RowExclusiveLock);
    heap_freetuple(atttup);
 
    /*
     * Make a dependency so that the pg_attrdef entry goes away if the column
     * (or whole table) is deleted.  In the case of a generated column, make
     * it an internal dependency to prevent the default expression from being
     * deleted separately.
     */
    colobject.classId = RelationRelationId;
    colobject.objectId = RelationGetRelid(rel);
    colobject.objectSubId = attnum;
 
    recordDependencyOn(&defobject, &colobject,
                       attgenerated ? DEPENDENCY_INTERNAL : DEPENDENCY_AUTO);
 
    /*
     * Record dependencies on objects used in the expression, too.
     */
    recordDependencyOnSingleRelExpr(&defobject, expr, RelationGetRelid(rel),
                                    DEPENDENCY_NORMAL,
                                    DEPENDENCY_NORMAL, false);
 
    /*
     * Post creation hook for attribute defaults.
     *
     * XXX. ALTER TABLE ALTER COLUMN SET/DROP DEFAULT is implemented with a
     * couple of deletion/creation of the attribute's default entry, so the
     * callee should check existence of an older version of this entry if it
     * needs to distinguish.
     */
    InvokeObjectPostCreateHookArg(AttrDefaultRelationId,
                                  RelationGetRelid(rel), attnum, is_internal);
 
    return attrdefOid;
}

References attnum, CatalogTupleInsert(), CatalogTupleUpdate(), ObjectAddress::classId, construct_array(), CreateExecutorState(), CStringGetTextDatum, DatumGetPointer(), DEPENDENCY_AUTO, DEPENDENCY_INTERNAL, DEPENDENCY_NORMAL, elog, ERROR, ExecEvalExpr(), ExecPrepareExpr(), expression_planner(), FreeExecutorState(), GetNewOidWithIndex(), GetPerTupleExprContext, GETSTRUCT, heap_form_tuple(), heap_freetuple(), heap_modify_tuple(), HeapTupleIsValid, Int16GetDatum(), InvokeObjectPostCreateHookArg, nodeToString(), ObjectAddress::objectId, ObjectIdGetDatum(), ObjectAddress::objectSubId, pfree(), PointerGetDatum(), RelationData::rd_att, RelationData::rd_rel, recordDependencyOn(), recordDependencyOnSingleRelExpr(), RelationGetDescr, RelationGetRelid, RowExclusiveLock, SearchSysCacheCopy2, HeapTupleData::t_self, table_close(), table_open(), TupleDescAttr, and values.

Referenced by AddRelationNewConstraints(), ATExecAlterColumnType(), ATExecCookedColumnDefault(), and StoreConstraints().

Variable Documentation

FormData_pg_attrdef

FormData_pg_attrdef

Definition at line 42 of file pg_attrdef.h.