/* ----------------
* index_beginscan - start a scan of an index
*
* Note: heapRelation may be NULL if there is no intention of calling
* index_getnext on this scan; index_getnext_indexitem will not use the
* heapRelation link (nor the snapshot). However, the caller had better
* be holding some kind of lock on the heap relation in any case, to ensure
* no one deletes it (or the index) out from under us.
* ----------------
*/
IndexScanDesc
index_beginscan(Relation heapRelation,
Relation indexRelation,
Snapshot snapshot,
int nkeys, ScanKey key)
{
IndexScanDesc scan;
RegProcedure procedure;
RELATION_CHECKS;
GET_REL_PROCEDURE(beginscan, ambeginscan);
RelationIncrementReferenceCount(indexRelation);
/*
* Acquire AccessShareLock for the duration of the scan
*
* Note: we could get an SI inval message here and consequently have to
* rebuild the relcache entry. The refcount increment above ensures
* that we will rebuild it and not just flush it...
*/
LockRelation(indexRelation, AccessShareLock);
/*
* Tell the AM to open a scan.
*/
scan = (IndexScanDesc)
DatumGetPointer(OidFunctionCall3(procedure,
PointerGetDatum(indexRelation),
Int32GetDatum(nkeys),
PointerGetDatum(key)));
/*
* Save additional parameters into the scandesc. Everything else was
* set up by RelationGetIndexScan.
*/
scan->heapRelation = heapRelation;
scan->xs_snapshot = snapshot;
/*
* We want to look up the amgettuple procedure just once per scan, not
* once per index_getnext call. So do it here and save the fmgr info
* result in the scan descriptor.
*/
GET_SCAN_PROCEDURE(beginscan, amgettuple);
fmgr_info(procedure, &scan->fn_getnext);
return scan;
}
static void
_bt_mergebuild(Spooler *self, BTSpool *btspool)
{
Relation heapRel = self->relinfo->ri_RelationDesc;
BTWriteState wstate;
BTReader reader;
bool merge;
Assert(btspool->index->rd_index->indisvalid);
tuplesort_performsort(btspool->sortstate);
wstate.index = btspool->index;
/*
* We need to log index creation in WAL iff WAL archiving is enabled AND
* it's not a temp index.
*/
wstate.btws_use_wal = self->use_wal &&
XLogArchivingActive() && !RELATION_IS_LOCAL(wstate.index);
/* reserve the metapage */
wstate.btws_pages_alloced = BTREE_METAPAGE + 1;
wstate.btws_pages_written = 0;
wstate.btws_zeropage = NULL; /* until needed */
/*
* Flush dirty buffers so that we will read the index files directly
* in order to get pre-existing data. We must acquire AccessExclusiveLock
* for the target table for calling FlushRelationBuffer().
*/
LockRelation(wstate.index, AccessExclusiveLock);
FlushRelationBuffers(wstate.index);
BULKLOAD_PROFILE(&prof_flush);
merge = BTReaderInit(&reader, wstate.index);
elog(DEBUG1, "pg_bulkload: build \"%s\" %s merge (%s wal)",
RelationGetRelationName(wstate.index),
merge ? "with" : "without",
wstate.btws_use_wal ? "with" : "without");
/* Assign a new file node. */
RelationSetNewRelfilenode(wstate.index, InvalidTransactionId);
if (merge || (btspool->isunique && self->max_dup_errors > 0))
{
/* Merge two streams into the new file node that we assigned. */
BULKLOAD_PROFILE_PUSH();
_bt_mergeload(self, &wstate, btspool, &reader, heapRel);
BULKLOAD_PROFILE_POP();
BULKLOAD_PROFILE(&prof_merge);
}
else
{
/* Fast path for newly created index. */
_bt_load(&wstate, btspool, NULL);
BULKLOAD_PROFILE(&prof_index);
}
BTReaderTerm(&reader);
}
/* ----------
* toast_save_datum -
*
* Save one single datum into the secondary relation and return
* a varattrib reference for it.
* ----------
*/
static Datum
toast_save_datum(Relation rel, Datum value)
{
Relation toastrel;
Relation toastidx;
HeapTuple toasttup;
TupleDesc toasttupDesc;
Datum t_values[3];
bool t_isnull[3];
varattrib *result;
struct
{
struct varlena hdr;
char data[TOAST_MAX_CHUNK_SIZE];
} chunk_data;
int32 chunk_size;
int32 chunk_seq = 0;
char *data_p;
int32 data_todo;
/*
* Open the toast relation and its index. We can use the index to check
* uniqueness of the OID we assign to the toasted item, even though it has
* additional columns besides OID.
*/
toastrel = heap_open(rel->rd_rel->reltoastrelid, RowExclusiveLock);
toasttupDesc = toastrel->rd_att;
toastidx = index_open(toastrel->rd_rel->reltoastidxid);
/*
* Create the varattrib reference
*/
result = (varattrib *) palloc(sizeof(varattrib));
result->va_header = sizeof(varattrib) | VARATT_FLAG_EXTERNAL;
if (VARATT_IS_COMPRESSED(value))
{
result->va_header |= VARATT_FLAG_COMPRESSED;
result->va_content.va_external.va_rawsize =
((varattrib *) value)->va_content.va_compressed.va_rawsize;
}
else
result->va_content.va_external.va_rawsize = VARATT_SIZE(value);
result->va_content.va_external.va_extsize =
VARATT_SIZE(value) - VARHDRSZ;
result->va_content.va_external.va_valueid =
GetNewOidWithIndex(toastrel, toastidx);
result->va_content.va_external.va_toastrelid =
rel->rd_rel->reltoastrelid;
/*
* Initialize constant parts of the tuple data
*/
t_values[0] = ObjectIdGetDatum(result->va_content.va_external.va_valueid);
t_values[2] = PointerGetDatum(&chunk_data);
t_isnull[0] = false;
t_isnull[1] = false;
t_isnull[2] = false;
/*
* Get the data to process
*/
data_p = VARATT_DATA(value);
data_todo = VARATT_SIZE(value) - VARHDRSZ;
/*
* We must explicitly lock the toast index because we aren't using an
* index scan here.
*/
LockRelation(toastidx, RowExclusiveLock);
/*
* Split up the item into chunks
*/
while (data_todo > 0)
{
/*
* Calculate the size of this chunk
*/
chunk_size = Min(TOAST_MAX_CHUNK_SIZE, data_todo);
/*
* Build a tuple and store it
*/
t_values[1] = Int32GetDatum(chunk_seq++);
VARATT_SIZEP(&chunk_data) = chunk_size + VARHDRSZ;
memcpy(VARATT_DATA(&chunk_data), data_p, chunk_size);
toasttup = heap_form_tuple(toasttupDesc, t_values, t_isnull);
if (!HeapTupleIsValid(toasttup))
elog(ERROR, "failed to build TOAST tuple");
simple_heap_insert(toastrel, toasttup);
/*
* Create the index entry. We cheat a little here by not using
* FormIndexDatum: this relies on the knowledge that the index columns
* are the same as the initial columns of the table.
*
* Note also that there had better not be any user-created index on
* the TOAST table, since we don't bother to update anything else.
*/
index_insert(toastidx, t_values, t_isnull,
&(toasttup->t_self),
toastrel, toastidx->rd_index->indisunique);
/*
* Free memory
*/
heap_freetuple(toasttup);
/*
* Move on to next chunk
*/
data_todo -= chunk_size;
data_p += chunk_size;
}
/*
* Done - close toast relation and return the reference
*/
UnlockRelation(toastidx, RowExclusiveLock);
index_close(toastidx);
heap_close(toastrel, RowExclusiveLock);
return PointerGetDatum(result);
}
/*
* index_drop
*
* NOTE: this routine should now only be called through performDeletion(),
* else associated dependencies won't be cleaned up.
*/
void
index_drop(Oid indexId)
{
Oid heapId;
Relation userHeapRelation;
Relation userIndexRelation;
Relation indexRelation;
HeapTuple tuple;
int i;
Assert(OidIsValid(indexId));
/*
* To drop an index safely, we must grab exclusive lock on its parent
* table; otherwise there could be other backends using the index!
* Exclusive lock on the index alone is insufficient because another
* backend might be in the midst of devising a query plan that will
* use the index. The parser and planner take care to hold an
* appropriate lock on the parent table while working, but having them
* hold locks on all the indexes too seems overly complex. We do grab
* exclusive lock on the index too, just to be safe. Both locks must
* be held till end of transaction, else other backends will still see
* this index in pg_index.
*/
heapId = IndexGetRelation(indexId);
userHeapRelation = heap_open(heapId, AccessExclusiveLock);
userIndexRelation = index_open(indexId);
LockRelation(userIndexRelation, AccessExclusiveLock);
/*
* fix RELATION relation
*/
DeleteRelationTuple(indexId);
/*
* fix ATTRIBUTE relation
*/
DeleteAttributeTuples(indexId);
/*
* fix INDEX relation
*/
indexRelation = heap_openr(IndexRelationName, RowExclusiveLock);
tuple = SearchSysCache(INDEXRELID,
ObjectIdGetDatum(indexId),
0, 0, 0);
if (!HeapTupleIsValid(tuple))
elog(ERROR, "cache lookup failed for index %u", indexId);
simple_heap_delete(indexRelation, &tuple->t_self);
ReleaseSysCache(tuple);
heap_close(indexRelation, RowExclusiveLock);
/*
* flush buffer cache and physically remove the file
*/
i = FlushRelationBuffers(userIndexRelation, (BlockNumber) 0);
if (i < 0)
elog(ERROR, "FlushRelationBuffers returned %d", i);
smgrunlink(DEFAULT_SMGR, userIndexRelation);
/*
* We are presently too lazy to attempt to compute the new correct
* value of relhasindex (the next VACUUM will fix it if necessary). So
* there is no need to update the pg_class tuple for the owning
* relation. But we must send out a shared-cache-inval notice on the
* owning relation to ensure other backends update their relcache
* lists of indexes.
*/
CacheInvalidateRelcache(heapId);
/*
* Close rels, but keep locks
*/
index_close(userIndexRelation);
heap_close(userHeapRelation, NoLock);
RelationForgetRelation(indexId);
}
/* ----------------------------------------------------------------
* index_create
*
* Returns OID of the created index.
* ----------------------------------------------------------------
*/
Oid
index_create(Oid heapRelationId,
const char *indexRelationName,
IndexInfo *indexInfo,
Oid accessMethodObjectId,
Oid *classObjectId,
bool primary,
bool isconstraint,
bool allow_system_table_mods)
{
Relation heapRelation;
Relation indexRelation;
TupleDesc indexTupDesc;
bool shared_relation;
Oid namespaceId;
Oid indexoid;
int i;
/*
* Only SELECT ... FOR UPDATE are allowed while doing this
*/
heapRelation = heap_open(heapRelationId, ShareLock);
/*
* The index will be in the same namespace as its parent table, and is
* shared across databases if and only if the parent is.
*/
namespaceId = RelationGetNamespace(heapRelation);
shared_relation = heapRelation->rd_rel->relisshared;
/*
* check parameters
*/
if (indexInfo->ii_NumIndexAttrs < 1)
elog(ERROR, "must index at least one column");
if (!allow_system_table_mods &&
IsSystemRelation(heapRelation) &&
IsNormalProcessingMode())
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("user-defined indexes on system catalog tables are not supported")));
/*
* We cannot allow indexing a shared relation after initdb (because
* there's no way to make the entry in other databases' pg_class).
* Unfortunately we can't distinguish initdb from a manually started
* standalone backend. However, we can at least prevent this mistake
* under normal multi-user operation.
*/
if (shared_relation && IsUnderPostmaster)
ereport(ERROR,
(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
errmsg("shared indexes cannot be created after initdb")));
if (get_relname_relid(indexRelationName, namespaceId))
ereport(ERROR,
(errcode(ERRCODE_DUPLICATE_TABLE),
errmsg("relation \"%s\" already exists",
indexRelationName)));
/*
* construct tuple descriptor for index tuples
*/
indexTupDesc = ConstructTupleDescriptor(heapRelation,
indexInfo,
classObjectId);
/*
* create the index relation's relcache entry and physical disk file.
* (If we fail further down, it's the smgr's responsibility to remove
* the disk file again.)
*/
indexRelation = heap_create(indexRelationName,
namespaceId,
indexTupDesc,
shared_relation,
true,
allow_system_table_mods);
/* Fetch the relation OID assigned by heap_create */
indexoid = RelationGetRelid(indexRelation);
/*
* Obtain exclusive lock on it. Although no other backends can see it
* until we commit, this prevents deadlock-risk complaints from lock
* manager in cases such as CLUSTER.
*/
LockRelation(indexRelation, AccessExclusiveLock);
/*
* Fill in fields of the index's pg_class entry that are not set
* correctly by heap_create.
*
* XXX should have a cleaner way to create cataloged indexes
*/
indexRelation->rd_rel->relowner = GetUserId();
indexRelation->rd_rel->relam = accessMethodObjectId;
indexRelation->rd_rel->relkind = RELKIND_INDEX;
indexRelation->rd_rel->relhasoids = false;
/*
* store index's pg_class entry
*/
UpdateRelationRelation(indexRelation);
/*
* now update the object id's of all the attribute tuple forms in the
* index relation's tuple descriptor
*/
InitializeAttributeOids(indexRelation,
indexInfo->ii_NumIndexAttrs,
indexoid);
/*
* append ATTRIBUTE tuples for the index
*/
AppendAttributeTuples(indexRelation, indexInfo->ii_NumIndexAttrs);
/* ----------------
* update pg_index
* (append INDEX tuple)
*
* Note that this stows away a representation of "predicate".
* (Or, could define a rule to maintain the predicate) --Nels, Feb '92
* ----------------
*/
UpdateIndexRelation(indexoid, heapRelationId, indexInfo,
classObjectId, primary);
/*
* Register constraint and dependencies for the index.
*
* If the index is from a CONSTRAINT clause, construct a pg_constraint
* entry. The index is then linked to the constraint, which in turn
* is linked to the table. If it's not a CONSTRAINT, make the
* dependency directly on the table.
*
* We don't need a dependency on the namespace, because there'll be an
* indirect dependency via our parent table.
*
* During bootstrap we can't register any dependencies, and we don't try
* to make a constraint either.
*/
if (!IsBootstrapProcessingMode())
{
ObjectAddress myself,
referenced;
myself.classId = RelOid_pg_class;
myself.objectId = indexoid;
myself.objectSubId = 0;
if (isconstraint)
{
char constraintType;
Oid conOid;
if (primary)
constraintType = CONSTRAINT_PRIMARY;
else if (indexInfo->ii_Unique)
constraintType = CONSTRAINT_UNIQUE;
else
{
elog(ERROR, "constraint must be PRIMARY or UNIQUE");
constraintType = 0; /* keep compiler quiet */
}
/* Shouldn't have any expressions */
if (indexInfo->ii_Expressions)
elog(ERROR, "constraints can't have index expressions");
conOid = CreateConstraintEntry(indexRelationName,
namespaceId,
constraintType,
false, /* isDeferrable */
false, /* isDeferred */
heapRelationId,
indexInfo->ii_KeyAttrNumbers,
indexInfo->ii_NumIndexAttrs,
InvalidOid, /* no domain */
InvalidOid, /* no foreign key */
NULL,
0,
' ',
' ',
' ',
InvalidOid, /* no associated index */
NULL, /* no check constraint */
NULL,
NULL);
referenced.classId = get_system_catalog_relid(ConstraintRelationName);
referenced.objectId = conOid;
referenced.objectSubId = 0;
recordDependencyOn(&myself, &referenced, DEPENDENCY_INTERNAL);
}
else
{
/* Create auto dependencies on simply-referenced columns */
for (i = 0; i < indexInfo->ii_NumIndexAttrs; i++)
{
if (indexInfo->ii_KeyAttrNumbers[i] != 0)
{
referenced.classId = RelOid_pg_class;
referenced.objectId = heapRelationId;
referenced.objectSubId = indexInfo->ii_KeyAttrNumbers[i];
recordDependencyOn(&myself, &referenced, DEPENDENCY_AUTO);
}
}
}
/* Store dependency on operator classes */
referenced.classId = get_system_catalog_relid(OperatorClassRelationName);
for (i = 0; i < indexInfo->ii_NumIndexAttrs; i++)
{
referenced.objectId = classObjectId[i];
referenced.objectSubId = 0;
recordDependencyOn(&myself, &referenced, DEPENDENCY_NORMAL);
}
/* Store dependencies on anything mentioned in index expressions */
if (indexInfo->ii_Expressions)
{
recordDependencyOnSingleRelExpr(&myself,
(Node *) indexInfo->ii_Expressions,
heapRelationId,
DEPENDENCY_NORMAL,
DEPENDENCY_AUTO);
}
/* Store dependencies on anything mentioned in predicate */
if (indexInfo->ii_Predicate)
{
recordDependencyOnSingleRelExpr(&myself,
(Node *) indexInfo->ii_Predicate,
heapRelationId,
DEPENDENCY_NORMAL,
DEPENDENCY_AUTO);
}
}
/*
* Advance the command counter so that we can see the newly-entered
* catalog tuples for the index.
*/
CommandCounterIncrement();
/*
* In bootstrap mode, we have to fill in the index strategy structure
* with information from the catalogs. If we aren't bootstrapping,
* then the relcache entry has already been rebuilt thanks to sinval
* update during CommandCounterIncrement.
*/
if (IsBootstrapProcessingMode())
RelationInitIndexAccessInfo(indexRelation);
else
Assert(indexRelation->rd_indexcxt != NULL);
/*
* If this is bootstrap (initdb) time, then we don't actually fill in
* the index yet. We'll be creating more indexes and classes later,
* so we delay filling them in until just before we're done with
* bootstrapping. Otherwise, we call the routine that constructs the
* index.
*
* In normal processing mode, the heap and index relations are closed by
* index_build() --- but we continue to hold the ShareLock on the heap
* and the exclusive lock on the index that we acquired above, until
* end of transaction.
*/
if (IsBootstrapProcessingMode())
{
index_register(heapRelationId, indexoid, indexInfo);
/* XXX shouldn't we close the heap and index rels here? */
}
else
index_build(heapRelation, indexRelation, indexInfo);
return indexoid;
}
/*
* reindex_index - This routine is used to recreate a single index
*/
void
reindex_index(Oid indexId)
{
Relation iRel,
heapRelation;
IndexInfo *indexInfo;
Oid heapId;
bool inplace;
/*
* Open our index relation and get an exclusive lock on it.
*
* Note: for REINDEX INDEX, doing this before opening the parent heap
* relation means there's a possibility for deadlock failure against
* another xact that is doing normal accesses to the heap and index.
* However, it's not real clear why you'd be wanting to do REINDEX INDEX
* on a table that's in active use, so I'd rather have the protection of
* making sure the index is locked down. In the REINDEX TABLE and
* REINDEX DATABASE cases, there is no problem because caller already
* holds exclusive lock on the parent table.
*/
iRel = index_open(indexId);
LockRelation(iRel, AccessExclusiveLock);
/* Get OID of index's parent table */
heapId = iRel->rd_index->indrelid;
/* Open and lock the parent heap relation */
heapRelation = heap_open(heapId, AccessExclusiveLock);
SetReindexProcessing(heapId, indexId);
/*
* If it's a shared index, we must do inplace processing (because we
* have no way to update relfilenode in other databases). Otherwise
* we can do it the normal transaction-safe way.
*
* Since inplace processing isn't crash-safe, we only allow it in a
* standalone backend. (In the REINDEX TABLE and REINDEX DATABASE cases,
* the caller should have detected this.)
*/
inplace = iRel->rd_rel->relisshared;
if (inplace && IsUnderPostmaster)
ereport(ERROR,
(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
errmsg("shared index \"%s\" can only be reindexed in stand-alone mode",
RelationGetRelationName(iRel))));
/* Fetch info needed for index_build */
indexInfo = BuildIndexInfo(iRel);
if (inplace)
{
/*
* Release any buffers associated with this index. If they're
* dirty, they're just dropped without bothering to flush to disk.
*/
DropRelationBuffers(iRel);
/* Now truncate the actual data and set blocks to zero */
smgrtruncate(DEFAULT_SMGR, iRel, 0);
iRel->rd_nblocks = 0;
iRel->rd_targblock = InvalidBlockNumber;
}
else
{
/*
* We'll build a new physical relation for the index.
*/
setNewRelfilenode(iRel);
}
/* Initialize the index and rebuild */
index_build(heapRelation, iRel, indexInfo);
/*
* index_build will close both the heap and index relations (but not
* give up the locks we hold on them). So we're done.
*/
SetReindexProcessing(InvalidOid, InvalidOid);
}