greenplumn toasting 源码
greenplumn toasting 代码
文件路径：/src/backend/catalog/toasting.c
/*-------------------------------------------------------------------------
*
* toasting.c
* This file contains routines to support creation of toast tables
*
*
* Portions Copyright (c) 1996-2019, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* IDENTIFICATION
* src/backend/catalog/toasting.c
*
*-------------------------------------------------------------------------
*/
#include "postgres.h"
#include "access/heapam.h"
#include "access/xact.h"
#include "catalog/binary_upgrade.h"
#include "catalog/catalog.h"
#include "catalog/dependency.h"
#include "catalog/heap.h"
#include "catalog/index.h"
#include "catalog/namespace.h"
#include "catalog/oid_dispatch.h"
#include "catalog/pg_am.h"
#include "catalog/pg_namespace.h"
#include "catalog/pg_opclass.h"
#include "catalog/pg_type.h"
#include "catalog/toasting.h"
#include "miscadmin.h"
#include "nodes/makefuncs.h"
#include "storage/lmgr.h"
#include "storage/lock.h"
#include "utils/builtins.h"
#include "utils/rel.h"
#include "utils/syscache.h"
static void CheckAndCreateToastTable(Oid relOid, Datum reloptions,
LOCKMODE lockmode, bool check);
static bool create_toast_table(Relation rel, Oid toastOid, Oid toastIndexOid,
Datum reloptions, LOCKMODE lockmode, bool check);
static bool needs_toast_table(Relation rel);
/*
* CreateToastTable variants
* If the table needs a toast table, and doesn't already have one,
* then create a toast table for it.
*
* reloptions for the toast table can be passed, too. Pass (Datum) 0
* for default reloptions.
*
* We expect the caller to have verified that the relation is a table and have
* already done any necessary permission checks. Callers expect this function
* to end with CommandCounterIncrement if it makes any changes.
*/
void
AlterTableCreateToastTable(Oid relOid, Datum reloptions, LOCKMODE lockmode)
{
CheckAndCreateToastTable(relOid, reloptions, lockmode, true);
}
void
NewHeapCreateToastTable(Oid relOid, Datum reloptions, LOCKMODE lockmode)
{
CheckAndCreateToastTable(relOid, reloptions, lockmode, false);
}
void
NewRelationCreateToastTable(Oid relOid, Datum reloptions)
{
CheckAndCreateToastTable(relOid, reloptions, AccessExclusiveLock, false);
}
static void
CheckAndCreateToastTable(Oid relOid, Datum reloptions, LOCKMODE lockmode, bool check)
{
Relation rel;
rel = table_open(relOid, lockmode);
/* create_toast_table does all the work */
(void) create_toast_table(rel, InvalidOid, InvalidOid, reloptions, lockmode, check);
table_close(rel, NoLock);
}
/*
* Create a toast table during bootstrap
*
* Here we need to prespecify the OIDs of the toast table and its index
*/
void
BootstrapToastTable(char *relName, Oid toastOid, Oid toastIndexOid)
{
Relation rel;
rel = table_openrv(makeRangeVar(NULL, relName, -1), AccessExclusiveLock);
if (rel->rd_rel->relkind != RELKIND_RELATION &&
rel->rd_rel->relkind != RELKIND_MATVIEW)
ereport(ERROR,
(errcode(ERRCODE_WRONG_OBJECT_TYPE),
errmsg("\"%s\" is not a table or materialized view",
relName)));
/* create_toast_table does all the work */
if (!create_toast_table(rel, toastOid, toastIndexOid, (Datum) 0,
AccessExclusiveLock, false))
elog(ERROR, "\"%s\" does not require a toast table",
relName);
table_close(rel, NoLock);
}
/*
* create_toast_table --- internal workhorse
*
* rel is already opened and locked
* toastOid and toastIndexOid are normally InvalidOid, but during
* bootstrap they can be nonzero to specify hand-assigned OIDs
*/
static bool
create_toast_table(Relation rel, Oid toastOid, Oid toastIndexOid,
Datum reloptions, LOCKMODE lockmode, bool check)
{
Oid relOid = RelationGetRelid(rel);
HeapTuple reltup;
TupleDesc tupdesc;
bool shared_relation;
bool mapped_relation;
Relation toast_rel;
Relation class_rel;
Oid toast_relid;
Oid toast_idxid;
Oid toast_typid = InvalidOid;
Oid namespaceid;
char toast_relname[NAMEDATALEN];
char toast_idxname[NAMEDATALEN];
IndexInfo *indexInfo;
Oid collationObjectId[2];
Oid classObjectId[2];
int16 coloptions[2];
ObjectAddress baseobject,
toastobject;
/*
* Is it already toasted?
*/
if (rel->rd_rel->reltoastrelid != InvalidOid)
return false;
/*
* Toast tables for regular relations go in pg_toast; those for temp
* relations go into the per-backend temp-toast-table namespace.
*/
if (isTempOrTempToastNamespace(rel->rd_rel->relnamespace))
namespaceid = GetTempToastNamespace();
else
namespaceid = PG_TOAST_NAMESPACE;
snprintf(toast_relname, sizeof(toast_relname),
"pg_toast_%u", relOid);
snprintf(toast_idxname, sizeof(toast_idxname),
"pg_toast_%u_index", relOid);
/*
* Check to see whether the table actually needs a TOAST table.
*/
if (!IsBinaryUpgrade)
{
/* Normal mode, normal check */
if (!needs_toast_table(rel))
return false;
}
else
{
/*
* In binary-upgrade mode, create a TOAST table if and only if
* pg_upgrade told us to (ie, a TOAST table OID has been provided).
*
* This indicates that the old cluster had a TOAST table for the
* current table. We must create a TOAST table to receive the old
* TOAST file, even if the table seems not to need one.
*
* Contrariwise, if the old cluster did not have a TOAST table, we
* should be able to get along without one even if the new version's
* needs_toast_table rules suggest we should have one. There is a lot
* of daylight between where we will create a TOAST table and where
* * one is really necessary to avoid failures, so small cross-version
* differences in the when-to-create heuristic shouldn't be a problem.
* If we tried to create a TOAST table anyway, we would have the
* problem that it might take up an OID that will conflict with some
* old-cluster table we haven't seen yet.
*/
if (IsBinaryUpgrade)
{
Assert(toastOid == InvalidOid);
toastOid = GetPreassignedOidForRelation(namespaceid, toast_relname);
if (!OidIsValid(toastOid))
return false;
toast_typid = GetPreassignedOidForType(namespaceid, toast_relname);
if (!OidIsValid(toast_typid))
return false;
}
}
/*
* If requested check lockmode is sufficient. This is a cross check in
* case of errors or conflicting decisions in earlier code.
*/
if (check && lockmode != AccessExclusiveLock)
elog(ERROR, "AccessExclusiveLock required to add toast table.");
/*
* Create the toast table and its index
*/
/* this is pretty painful... need a tuple descriptor */
tupdesc = CreateTemplateTupleDesc(3);
TupleDescInitEntry(tupdesc, (AttrNumber) 1,
"chunk_id",
OIDOID,
-1, 0);
TupleDescInitEntry(tupdesc, (AttrNumber) 2,
"chunk_seq",
INT4OID,
-1, 0);
TupleDescInitEntry(tupdesc, (AttrNumber) 3,
"chunk_data",
BYTEAOID,
-1, 0);
/*
* Ensure that the toast table doesn't itself get toasted, or we'll be
* toast :-(. This is essential for chunk_data because type bytea is
* toastable; hit the other two just to be sure.
*/
TupleDescAttr(tupdesc, 0)->attstorage = 'p';
TupleDescAttr(tupdesc, 1)->attstorage = 'p';
TupleDescAttr(tupdesc, 2)->attstorage = 'p';
/*
* Use binary-upgrade override for pg_type.oid, if supplied. We might be
* in the post-schema-restore phase where we are doing ALTER TABLE to
* create TOAST tables that didn't exist in the old cluster.
*
* GPDB: already got the OIDs above
*/
/* Toast table is shared if and only if its parent is. */
shared_relation = rel->rd_rel->relisshared;
/* It's mapped if and only if its parent is, too */
mapped_relation = RelationIsMapped(rel);
toast_relid = heap_create_with_catalog(toast_relname,
namespaceid,
rel->rd_rel->reltablespace,
toastOid,
toast_typid,
InvalidOid,
rel->rd_rel->relowner,
RelationIsAoRows(rel) ?
HEAP_TABLE_AM_OID :rel->rd_rel->relam,
tupdesc,
NIL,
RELKIND_TOASTVALUE,
rel->rd_rel->relpersistence,
shared_relation,
mapped_relation,
ONCOMMIT_NOOP,
NULL, /* CDB POLICY */
reloptions,
false,
true,
true,
InvalidOid,
NULL,
/* valid_opts */ false);
Assert(toast_relid != InvalidOid);
/* make the toast relation visible, else table_open will fail */
CommandCounterIncrement();
/* ShareLock is not really needed here, but take it anyway */
toast_rel = table_open(toast_relid, ShareLock);
/*
* Create unique index on chunk_id, chunk_seq.
*
* NOTE: the normal TOAST access routines could actually function with a
* single-column index on chunk_id only. However, the slice access
* routines use both columns for faster access to an individual chunk. In
* addition, we want it to be unique as a check against the possibility of
* duplicate TOAST chunk OIDs. The index might also be a little more
* efficient this way, since btree isn't all that happy with large numbers
* of equal keys.
*/
indexInfo = makeNode(IndexInfo);
indexInfo->ii_NumIndexAttrs = 2;
indexInfo->ii_NumIndexKeyAttrs = 2;
indexInfo->ii_IndexAttrNumbers[0] = 1;
indexInfo->ii_IndexAttrNumbers[1] = 2;
indexInfo->ii_Expressions = NIL;
indexInfo->ii_ExpressionsState = NIL;
indexInfo->ii_Predicate = NIL;
indexInfo->ii_PredicateState = NULL;
indexInfo->ii_ExclusionOps = NULL;
indexInfo->ii_ExclusionProcs = NULL;
indexInfo->ii_ExclusionStrats = NULL;
indexInfo->ii_Unique = true;
indexInfo->ii_ReadyForInserts = true;
indexInfo->ii_Concurrent = false;
indexInfo->ii_BrokenHotChain = false;
indexInfo->ii_ParallelWorkers = 0;
indexInfo->ii_Am = BTREE_AM_OID;
indexInfo->ii_AmCache = NULL;
indexInfo->ii_Context = CurrentMemoryContext;
collationObjectId[0] = InvalidOid;
collationObjectId[1] = InvalidOid;
classObjectId[0] = OID_BTREE_OPS_OID;
classObjectId[1] = INT4_BTREE_OPS_OID;
coloptions[0] = 0;
coloptions[1] = 0;
toast_idxid = index_create(toast_rel, toast_idxname, toastIndexOid, InvalidOid,
InvalidOid, InvalidOid,
indexInfo,
list_make2("chunk_id", "chunk_seq"),
BTREE_AM_OID,
rel->rd_rel->reltablespace,
collationObjectId, classObjectId, coloptions, (Datum) 0,
INDEX_CREATE_IS_PRIMARY, 0, true, true, NULL);
table_close(toast_rel, NoLock);
/*
* Store the toast table's OID in the parent relation's pg_class row
*/
class_rel = table_open(RelationRelationId, RowExclusiveLock);
reltup = SearchSysCacheCopy1(RELOID, ObjectIdGetDatum(relOid));
if (!HeapTupleIsValid(reltup))
elog(ERROR, "cache lookup failed for relation %u", relOid);
((Form_pg_class) GETSTRUCT(reltup))->reltoastrelid = toast_relid;
if (!IsBootstrapProcessingMode())
{
/* normal case, use a transactional update */
CatalogTupleUpdate(class_rel, &reltup->t_self, reltup);
}
else
{
/* While bootstrapping, we cannot UPDATE, so overwrite in-place */
heap_inplace_update(class_rel, reltup);
}
heap_freetuple(reltup);
table_close(class_rel, RowExclusiveLock);
/*
* Register dependency from the toast table to the master, so that the
* toast table will be deleted if the master is. Skip this in bootstrap
* mode.
*/
if (!IsBootstrapProcessingMode())
{
baseobject.classId = RelationRelationId;
baseobject.objectId = relOid;
baseobject.objectSubId = 0;
toastobject.classId = RelationRelationId;
toastobject.objectId = toast_relid;
toastobject.objectSubId = 0;
recordDependencyOn(&toastobject, &baseobject, DEPENDENCY_INTERNAL);
}
/*
* Make changes visible
*/
CommandCounterIncrement();
return true;
}
/*
* Check to see whether the table needs a TOAST table.
*/
static bool
needs_toast_table(Relation rel)
{
/*
* No need to create a TOAST table for partitioned tables.
*/
if (rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE)
return false;
/*
* We cannot allow toasting a shared relation after initdb (because
* there's no way to mark it toasted in other databases' pg_class).
*/
if (rel->rd_rel->relisshared && !IsBootstrapProcessingMode())
return false;
/*
* Ignore attempts to create toast tables on catalog tables after initdb.
* Which catalogs get toast tables is explicitly chosen in
* catalog/toasting.h. (We could get here via some ALTER TABLE command if
* the catalog doesn't have a toast table.)
*/
if (IsCatalogRelation(rel) && !IsBootstrapProcessingMode())
return false;
/* Otherwise, let the AM decide. */
return table_relation_needs_toast_table(rel);
}
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