/*
* index_beginscan_internal --- common code for index_beginscan variants
*/
static IndexScanDesc
index_beginscan_internal(Relation indexRelation,
int nkeys, int norderbys, Snapshot snapshot)
{
IndexScanDesc scan;
FmgrInfo *procedure;
RELATION_CHECKS;
GET_REL_PROCEDURE(ambeginscan);
if (!(indexRelation->rd_am->ampredlocks))
PredicateLockRelation(indexRelation, snapshot);
/*
* We hold a reference count to the relcache entry throughout the scan.
*/
RelationIncrementReferenceCount(indexRelation);
/*
* Tell the AM to open a scan.
*/
scan = (IndexScanDesc)
DatumGetPointer(FunctionCall3(procedure,
PointerGetDatum(indexRelation),
Int32GetDatum(nkeys),
Int32GetDatum(norderbys)));
return scan;
}
/*
* index_beginscan_internal --- common code for index_beginscan variants
*/
static IndexScanDesc
index_beginscan_internal(Relation indexRelation,
int nkeys, int norderbys, Snapshot snapshot,
ParallelIndexScanDesc pscan, bool temp_snap)
{
IndexScanDesc scan;
RELATION_CHECKS;
CHECK_REL_PROCEDURE(ambeginscan);
if (!(indexRelation->rd_amroutine->ampredlocks))
PredicateLockRelation(indexRelation, snapshot);
/*
* We hold a reference count to the relcache entry throughout the scan.
*/
RelationIncrementReferenceCount(indexRelation);
/*
* Tell the AM to open a scan.
*/
scan = indexRelation->rd_amroutine->ambeginscan(indexRelation, nkeys,
norderbys);
/* Initialize information for parallel scan. */
scan->parallel_scan = pscan;
scan->xs_temp_snap = temp_snap;
return scan;
}
/*
* ConditionalLockRelation
*
* As above, but only lock if we can get the lock without blocking.
* Returns TRUE iff the lock was acquired.
*
* NOTE: we do not currently need conditional versions of all the
* LockXXX routines in this file, but they could easily be added if needed.
*/
bool
ConditionalLockRelation(Relation relation, LOCKMODE lockmode)
{
LOCKTAG tag;
MemSet(&tag, 0, sizeof(tag));
tag.relId = relation->rd_lockInfo.lockRelId.relId;
tag.dbId = relation->rd_lockInfo.lockRelId.dbId;
tag.objId.blkno = InvalidBlockNumber;
if (!LockAcquire(LockTableId, &tag, GetCurrentTransactionId(),
lockmode, true))
return false;
/*
* Check to see if the relcache entry has been invalidated while we
* were waiting to lock it. If so, rebuild it, or ereport() trying.
* Increment the refcount to ensure that RelationFlushRelation will
* rebuild it and not just delete it.
*/
RelationIncrementReferenceCount(relation);
AcceptInvalidationMessages();
RelationDecrementReferenceCount(relation);
return true;
}
/*
* index_beginscan_internal --- common code for index_beginscan variants
*/
static IndexScanDesc
index_beginscan_internal(Relation indexRelation,
int nkeys, ScanKey key)
{
IndexScanDesc scan;
FmgrInfo *procedure;
RELATION_CHECKS;
GET_REL_PROCEDURE(ambeginscan);
/*
* We hold a reference count to the relcache entry throughout the scan.
*/
RelationIncrementReferenceCount(indexRelation);
/*
* Tell the AM to open a scan.
*/
scan = (IndexScanDesc)
DatumGetPointer(FunctionCall3(procedure,
PointerGetDatum(indexRelation),
Int32GetDatum(nkeys),
PointerGetDatum(key)));
return scan;
}
/* ----------------
* 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;
}
/**
*begin scanning of a parquet relation
*/
ParquetScanDesc
parquet_beginscan(
Relation relation,
Snapshot parquetMetaDataSnapshot,
TupleDesc relationTupleDesc,
bool *proj)
{
ParquetScanDesc scan;
AppendOnlyEntry *aoEntry;
AppendOnlyStorageAttributes *attr;
/*
* increment relation ref count while scanning relation
*
* This is just to make really sure the relcache entry won't go away while
* the scan has a pointer to it. Caller should be holding the rel open
* anyway, so this is redundant in all normal scenarios...
*/
RelationIncrementReferenceCount(relation);
/* allocate scan descriptor */
scan = (ParquetScanDescData *)palloc0(sizeof(ParquetScanDescData));
/*
* Get the pg_appendonly information for this table
*/
aoEntry = GetAppendOnlyEntry(RelationGetRelid(relation), parquetMetaDataSnapshot);
scan->aoEntry = aoEntry;
Assert(aoEntry->majorversion == 1 && aoEntry->minorversion == 0);
#ifdef FAULT_INJECTOR
FaultInjector_InjectFaultIfSet(
FailQeWhenBeginParquetScan,
DDLNotSpecified,
"", // databaseName
""); // tableName
#endif
/*
* initialize the scan descriptor
*/
scan->pqs_filenamepath_maxlen = AOSegmentFilePathNameLen(relation) + 1;
scan->pqs_filenamepath = (char*)palloc0(scan->pqs_filenamepath_maxlen);
scan->pqs_rd = relation;
scan->parquetScanInitContext = CurrentMemoryContext;
/*
* Fill in Parquet Storage layer attributes.
*/
attr = &scan->storageAttributes;
/*
* These attributes describe the AppendOnly format to be scanned.
*/
if (aoEntry->compresstype == NULL || pg_strcasecmp(aoEntry->compresstype, "none") == 0)
attr->compress = false;
else
attr->compress = true;
if (aoEntry->compresstype != NULL)
attr->compressType = aoEntry->compresstype;
else
attr->compressType = "none";
attr->compressLevel = aoEntry->compresslevel;
attr->checksum = aoEntry->checksum;
attr->safeFSWriteSize = aoEntry->safefswritesize;
attr->splitsize = aoEntry->splitsize;
attr->version = aoEntry->version;
AORelationVersion_CheckValid(attr->version);
scan->proj = proj;
scan->pqs_tupDesc = (relationTupleDesc == NULL) ? RelationGetDescr(relation) : relationTupleDesc;
scan->hawqAttrToParquetColChunks = (int*)palloc0(scan->pqs_tupDesc->natts * sizeof(int));
initscan(scan);
return scan ;
}
