Merge pull request #15 from citusdata/vacuum

Initial support for VACUUM (without FULL option)
merge-cstore-pykello
Hadi Moshayedi 2020-10-09 21:10:34 -07:00 committed by GitHub
commit 685d5c9d4c
10 changed files with 632 additions and 16 deletions

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@ -35,6 +35,7 @@ DATA = cstore_fdw--1.7.sql cstore_fdw--1.6--1.7.sql cstore_fdw--1.5--1.6.sql cs
cstore_fdw--1.0--1.1.sql cstore_fdw--1.7--1.8.sql
REGRESS = extension_create
ISOLATION = create
EXTRA_CLEAN = cstore.pb-c.h cstore.pb-c.c data/*.cstore data/*.cstore.footer \
sql/block_filtering.sql sql/create.sql sql/data_types.sql sql/load.sql \
sql/copyto.sql expected/block_filtering.out expected/create.out \
@ -54,6 +55,7 @@ ifeq ($(USE_TABLEAM),yes)
OBJS += cstore_tableam.o
REGRESS += am_create am_load am_query am_analyze am_data_types am_functions \
am_drop am_insert am_copyto am_alter am_rollback am_truncate am_vacuum am_clean
ISOLATION += am_vacuum_vs_insert
endif
ifeq ($(enable_coverage),yes)
@ -76,6 +78,22 @@ PG_CONFIG = pg_config
PGXS := $(shell $(PG_CONFIG) --pgxs)
include $(PGXS)
# command for getting postgres source directory is taken from citus/configure.in
POSTGRES_SRCDIR=$(shell grep ^abs_top_srcdir $(shell dirname $(shell $(PG_CONFIG) --pgxs))/../Makefile.global|cut -d ' ' -f3-)
PGXS_ISOLATION_TESTER=$(top_builddir)/src/test/isolation/pg_isolation_regress
# If postgres installation doesn't include pg_isolation_regress, try using the
# one in postgres source directory.
ifeq (,$(wildcard $(PGXS_ISOLATION_TESTER)))
pg_isolation_regress_installcheck = \
$(POSTGRES_SRCDIR)/src/test/isolation/pg_isolation_regress \
--inputdir=$(srcdir) $(EXTRA_REGRESS_OPTS)
else
pg_isolation_regress_installcheck = \
$(PGXS_ISOLATION_TESTER) \
--inputdir=$(srcdir) $(EXTRA_REGRESS_OPTS)
endif
installcheck:
reindent:

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@ -20,6 +20,7 @@
#include "storage/bufpage.h"
#include "storage/lockdefs.h"
#include "utils/relcache.h"
#include "utils/snapmgr.h"
/* Defines for valid option names */
#define OPTION_NAME_COMPRESSION_TYPE "compression"
@ -284,6 +285,7 @@ extern void DeleteDataFileMetadataRowIfExists(Oid relfilenode);
extern void InitCStoreDataFileMetadata(Oid relfilenode, int blockRowCount);
extern void InsertStripeMetadataRow(Oid relfilenode, StripeMetadata *stripe);
extern DataFileMetadata * ReadDataFileMetadata(Oid relfilenode, bool missingOk);
extern uint64 GetHighestUsedAddress(Oid relfilenode);
extern void SaveStripeSkipList(Oid relfilenode, uint64 stripe,
StripeSkipList *stripeSkipList,
TupleDesc tupleDescriptor);

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@ -43,6 +43,7 @@ typedef struct
EState *estate;
} ModifyState;
static List * ReadDataFileStripeList(Oid relfilenode, Snapshot snapshot);
static Oid CStoreStripesRelationId(void);
static Oid CStoreStripesIndexRelationId(void);
static Oid CStoreDataFilesRelationId(void);
@ -345,17 +346,8 @@ InsertStripeMetadataRow(Oid relfilenode, StripeMetadata *stripe)
DataFileMetadata *
ReadDataFileMetadata(Oid relfilenode, bool missingOk)
{
Oid cstoreStripesOid = InvalidOid;
Relation cstoreStripes = NULL;
Relation index = NULL;
TupleDesc tupleDescriptor = NULL;
ScanKeyData scanKey[1];
SysScanDesc scanDescriptor = NULL;
HeapTuple heapTuple;
bool found = false;
DataFileMetadata *datafileMetadata = palloc0(sizeof(DataFileMetadata));
found = ReadCStoreDataFiles(relfilenode, &datafileMetadata->blockRowCount);
bool found = ReadCStoreDataFiles(relfilenode, &datafileMetadata->blockRowCount);
if (!found)
{
if (!missingOk)
@ -369,6 +361,56 @@ ReadDataFileMetadata(Oid relfilenode, bool missingOk)
}
}
datafileMetadata->stripeMetadataList =
ReadDataFileStripeList(relfilenode, GetTransactionSnapshot());
return datafileMetadata;
}
/*
* GetHighestUsedAddress returns the highest used address for the given
* relfilenode across all active and inactive transactions.
*/
uint64
GetHighestUsedAddress(Oid relfilenode)
{
uint64 highestUsedAddress = 0;
ListCell *stripeMetadataCell = NULL;
List *stripeMetadataList = NIL;
SnapshotData SnapshotDirty;
InitDirtySnapshot(SnapshotDirty);
stripeMetadataList = ReadDataFileStripeList(relfilenode, &SnapshotDirty);
foreach(stripeMetadataCell, stripeMetadataList)
{
StripeMetadata *stripe = lfirst(stripeMetadataCell);
uint64 lastByte = stripe->fileOffset + stripe->dataLength - 1;
highestUsedAddress = Max(highestUsedAddress, lastByte);
}
return highestUsedAddress;
}
/*
* ReadDataFileStripeList reads the stripe list for a given relfilenode
* in the given snapshot.
*/
static List *
ReadDataFileStripeList(Oid relfilenode, Snapshot snapshot)
{
List *stripeMetadataList = NIL;
Oid cstoreStripesOid = InvalidOid;
Relation cstoreStripes = NULL;
Relation index = NULL;
TupleDesc tupleDescriptor = NULL;
ScanKeyData scanKey[1];
SysScanDesc scanDescriptor = NULL;
HeapTuple heapTuple;
ScanKeyInit(&scanKey[0], Anum_cstore_stripes_relfilenode,
BTEqualStrategyNumber, F_OIDEQ, Int32GetDatum(relfilenode));
@ -377,7 +419,8 @@ ReadDataFileMetadata(Oid relfilenode, bool missingOk)
index = index_open(CStoreStripesIndexRelationId(), AccessShareLock);
tupleDescriptor = RelationGetDescr(cstoreStripes);
scanDescriptor = systable_beginscan_ordered(cstoreStripes, index, NULL, 1, scanKey);
scanDescriptor = systable_beginscan_ordered(cstoreStripes, index, NULL, 1,
scanKey);
while (HeapTupleIsValid(heapTuple = systable_getnext(scanDescriptor)))
{
@ -402,16 +445,14 @@ ReadDataFileMetadata(Oid relfilenode, bool missingOk)
stripeMetadata->rowCount = DatumGetInt64(
datumArray[Anum_cstore_stripes_row_count - 1]);
datafileMetadata->stripeMetadataList = lappend(
datafileMetadata->stripeMetadataList,
stripeMetadata);
stripeMetadataList = lappend(stripeMetadataList, stripeMetadata);
}
systable_endscan_ordered(scanDescriptor);
index_close(index, NoLock);
heap_close(cstoreStripes, NoLock);
return datafileMetadata;
return stripeMetadataList;
}

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@ -32,6 +32,7 @@
#include "storage/procarray.h"
#include "storage/smgr.h"
#include "utils/builtins.h"
#include "utils/pg_rusage.h"
#include "utils/rel.h"
#include "utils/syscache.h"
@ -40,6 +41,14 @@
#define CSTORE_TABLEAM_NAME "cstore_tableam"
/*
* Timing parameters for truncate locking heuristics.
*
* These are the same values from src/backend/access/heap/vacuumlazy.c
*/
#define VACUUM_TRUNCATE_LOCK_WAIT_INTERVAL 50 /* ms */
#define VACUUM_TRUNCATE_LOCK_TIMEOUT 5000 /* ms */
typedef struct CStoreScanDescData
{
TableScanDescData cs_base;
@ -58,6 +67,11 @@ static void CStoreTableAMObjectAccessHook(ObjectAccessType access, Oid classId,
objectId, int subId,
void *arg);
static bool IsCStoreTableAmTable(Oid relationId);
static bool ConditionalLockRelationWithTimeout(Relation rel, LOCKMODE lockMode,
int timeout, int retryInterval);
static void LogRelationStats(Relation rel, int elevel);
static char * CompressionTypeStr(CompressionType type);
static void TruncateCStore(Relation rel, int elevel);
static CStoreOptions *
CStoreTableAMGetOptions(void)
@ -575,6 +589,256 @@ cstore_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
}
/*
* cstore_vacuum_rel implements VACUUM without FULL option.
*/
static void
cstore_vacuum_rel(Relation rel, VacuumParams *params,
BufferAccessStrategy bstrategy)
{
int elevel = (params->options & VACOPT_VERBOSE) ? INFO : DEBUG2;
/* this should have been resolved by vacuum.c until now */
Assert(params->truncate != VACOPT_TERNARY_DEFAULT);
LogRelationStats(rel, elevel);
/*
* We don't have updates, deletes, or concurrent updates, so all we
* care for now is truncating the unused space at the end of storage.
*/
if (params->truncate == VACOPT_TERNARY_ENABLED)
{
TruncateCStore(rel, elevel);
}
}
static void
LogRelationStats(Relation rel, int elevel)
{
DataFileMetadata *datafileMetadata = NULL;
ListCell *stripeMetadataCell = NULL;
Oid relfilenode = rel->rd_node.relNode;
StringInfo infoBuf = makeStringInfo();
int compressionStats[COMPRESSION_COUNT] = { 0 };
uint64 totalStripeLength = 0;
uint64 tupleCount = 0;
uint64 blockCount = 0;
uint64 relPages = 0;
int stripeCount = 0;
TupleDesc tupdesc = RelationGetDescr(rel);
uint64 droppedBlocksWithData = 0;
datafileMetadata = ReadDataFileMetadata(relfilenode, false);
stripeCount = list_length(datafileMetadata->stripeMetadataList);
foreach(stripeMetadataCell, datafileMetadata->stripeMetadataList)
{
StripeMetadata *stripe = lfirst(stripeMetadataCell);
StripeSkipList *skiplist = ReadStripeSkipList(relfilenode, stripe->id,
RelationGetDescr(rel),
stripe->blockCount);
for (uint32 column = 0; column < skiplist->columnCount; column++)
{
bool attrDropped = tupdesc->attrs[column].attisdropped;
for (uint32 block = 0; block < skiplist->blockCount; block++)
{
ColumnBlockSkipNode *skipnode =
&skiplist->blockSkipNodeArray[column][block];
/* ignore zero length blocks for dropped attributes */
if (skipnode->valueLength > 0)
{
compressionStats[skipnode->valueCompressionType]++;
blockCount++;
if (attrDropped)
{
droppedBlocksWithData++;
}
}
}
}
tupleCount += stripe->rowCount;
totalStripeLength += stripe->dataLength;
}
RelationOpenSmgr(rel);
relPages = smgrnblocks(rel->rd_smgr, MAIN_FORKNUM);
RelationCloseSmgr(rel);
appendStringInfo(infoBuf, "total file size: %ld, total data size: %ld\n",
relPages * BLCKSZ, totalStripeLength);
appendStringInfo(infoBuf,
"total row count: %ld, stripe count: %d, "
"average rows per stripe: %ld\n",
tupleCount, stripeCount, tupleCount / stripeCount);
appendStringInfo(infoBuf,
"block count: %ld"
", containing data for dropped columns: %ld",
blockCount, droppedBlocksWithData);
for (int compressionType = 0; compressionType < COMPRESSION_COUNT; compressionType++)
{
appendStringInfo(infoBuf,
", %s compressed: %d",
CompressionTypeStr(compressionType),
compressionStats[compressionType]);
}
appendStringInfoString(infoBuf, "\n");
ereport(elevel, (errmsg("statistics for \"%s\":\n%s", RelationGetRelationName(rel),
infoBuf->data)));
}
/*
* CompressionTypeStr returns string representation of a compression type.
*/
static char *
CompressionTypeStr(CompressionType type)
{
switch (type)
{
case COMPRESSION_NONE:
return "none";
case COMPRESSION_PG_LZ:
return "pglz";
default:
return "unknown";
}
}
/*
* TruncateCStore truncates the unused space at the end of main fork for
* a cstore table. This unused space can be created by aborted transactions.
*
* This implementation is based on heap_vacuum_rel in vacuumlazy.c with some
* changes so it suits columnar store relations.
*/
static void
TruncateCStore(Relation rel, int elevel)
{
PGRUsage ru0;
BlockNumber old_rel_pages = 0;
BlockNumber new_rel_pages = 0;
SmgrAddr highestPhysicalAddress;
pg_rusage_init(&ru0);
/* Report that we are now truncating */
pgstat_progress_update_param(PROGRESS_VACUUM_PHASE,
PROGRESS_VACUUM_PHASE_TRUNCATE);
/*
* We need access exclusive lock on the relation in order to do
* truncation. If we can't get it, give up rather than waiting --- we
* don't want to block other backends, and we don't want to deadlock
* (which is quite possible considering we already hold a lower-grade
* lock).
*
* The decisions for AccessExclusiveLock and conditional lock with
* a timeout is based on lazy_truncate_heap in vacuumlazy.c.
*/
if (!ConditionalLockRelationWithTimeout(rel, AccessExclusiveLock,
VACUUM_TRUNCATE_LOCK_TIMEOUT,
VACUUM_TRUNCATE_LOCK_WAIT_INTERVAL))
{
/*
* We failed to establish the lock in the specified number of
* retries. This means we give up truncating.
*/
ereport(elevel,
(errmsg("\"%s\": stopping truncate due to conflicting lock request",
RelationGetRelationName(rel))));
return;
}
RelationOpenSmgr(rel);
old_rel_pages = smgrnblocks(rel->rd_smgr, MAIN_FORKNUM);
RelationCloseSmgr(rel);
/*
* Due to the AccessExclusive lock there's no danger that
* new stripes be added beyond highestPhysicalAddress while
* we're truncating.
*/
highestPhysicalAddress =
logical_to_smgr(GetHighestUsedAddress(rel->rd_node.relNode));
new_rel_pages = highestPhysicalAddress.blockno + 1;
if (new_rel_pages == old_rel_pages)
{
UnlockRelation(rel, AccessExclusiveLock);
return;
}
/*
* Truncate the storage. Note that RelationTruncate() takes care of
* Write Ahead Logging.
*/
RelationTruncate(rel, new_rel_pages);
/*
* We can release the exclusive lock as soon as we have truncated.
* Other backends can't safely access the relation until they have
* processed the smgr invalidation that smgrtruncate sent out ... but
* that should happen as part of standard invalidation processing once
* they acquire lock on the relation.
*/
UnlockRelation(rel, AccessExclusiveLock);
ereport(elevel,
(errmsg("\"%s\": truncated %u to %u pages",
RelationGetRelationName(rel),
old_rel_pages, new_rel_pages),
errdetail_internal("%s", pg_rusage_show(&ru0))));
}
/*
* ConditionalLockRelationWithTimeout tries to acquire a relation lock until
* it either succeeds or timesout. It doesn't enter wait queue and instead it
* sleeps between lock tries.
*
* This is based on the lock loop in lazy_truncate_heap().
*/
static bool
ConditionalLockRelationWithTimeout(Relation rel, LOCKMODE lockMode, int timeout,
int retryInterval)
{
int lock_retry = 0;
while (true)
{
if (ConditionalLockRelation(rel, lockMode))
{
break;
}
/*
* Check for interrupts while trying to (re-)acquire the lock
*/
CHECK_FOR_INTERRUPTS();
if (++lock_retry > (timeout / retryInterval))
{
return false;
}
pg_usleep(retryInterval * 1000L);
}
return true;
}
static bool
cstore_scan_analyze_next_block(TableScanDesc scan, BlockNumber blockno,
BufferAccessStrategy bstrategy)
@ -853,7 +1117,7 @@ static const TableAmRoutine cstore_am_methods = {
.relation_nontransactional_truncate = cstore_relation_nontransactional_truncate,
.relation_copy_data = cstore_relation_copy_data,
.relation_copy_for_cluster = cstore_relation_copy_for_cluster,
.relation_vacuum = heap_vacuum_rel,
.relation_vacuum = cstore_vacuum_rel,
.scan_analyze_next_block = cstore_scan_analyze_next_block,
.scan_analyze_next_tuple = cstore_scan_analyze_next_tuple,
.index_build_range_scan = cstore_index_build_range_scan,

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@ -95,6 +95,114 @@ SELECT count(*) - :columnar_table_count FROM cstore.cstore_data_files;
1
(1 row)
-- do this in a transaction so concurrent autovacuum doesn't interfere with results
BEGIN;
SAVEPOINT s1;
SELECT count(*) FROM t;
count
-------
2530
(1 row)
SELECT pg_size_pretty(pg_relation_size('t'));
pg_size_pretty
----------------
16 kB
(1 row)
INSERT INTO t SELECT i FROM generate_series(1, 10000) i;
SELECT pg_size_pretty(pg_relation_size('t'));
pg_size_pretty
----------------
56 kB
(1 row)
SELECT count(*) FROM t;
count
-------
12530
(1 row)
ROLLBACK TO SAVEPOINT s1;
-- not truncated by VACUUM or autovacuum yet (being in transaction ensures this),
-- so relation size should be same as before.
SELECT pg_size_pretty(pg_relation_size('t'));
pg_size_pretty
----------------
56 kB
(1 row)
COMMIT;
-- vacuum should truncate the relation to the usable space
VACUUM VERBOSE t;
INFO: statistics for "t":
total file size: 57344, total data size: 10754
total row count: 2530, stripe count: 3, average rows per stripe: 843
block count: 3, containing data for dropped columns: 0, none compressed: 3, pglz compressed: 0
INFO: "t": truncated 7 to 2 pages
DETAIL: CPU: user: 0.00 s, system: 0.00 s, elapsed: 0.00 s
SELECT pg_size_pretty(pg_relation_size('t'));
pg_size_pretty
----------------
16 kB
(1 row)
SELECT count(*) FROM t;
count
-------
2530
(1 row)
-- add some stripes with different compression types and create some gaps,
-- then vacuum to print stats
BEGIN;
SET cstore.block_row_count TO 1000;
SET cstore.stripe_row_count TO 2000;
SET cstore.compression TO "pglz";
SAVEPOINT s1;
INSERT INTO t SELECT i FROM generate_series(1, 1500) i;
ROLLBACK TO SAVEPOINT s1;
INSERT INTO t SELECT i / 5 FROM generate_series(1, 1500) i;
SET cstore.compression TO "none";
SAVEPOINT s2;
INSERT INTO t SELECT i FROM generate_series(1, 1500) i;
ROLLBACK TO SAVEPOINT s2;
INSERT INTO t SELECT i / 5 FROM generate_series(1, 1500) i;
COMMIT;
VACUUM VERBOSE t;
INFO: statistics for "t":
total file size: 24576, total data size: 18808
total row count: 5530, stripe count: 5, average rows per stripe: 1106
block count: 7, containing data for dropped columns: 0, none compressed: 5, pglz compressed: 2
SELECT count(*) FROM t;
count
-------
5530
(1 row)
-- check that we report blocks with data for dropped columns
ALTER TABLE t ADD COLUMN c int;
INSERT INTO t SELECT 1, i / 5 FROM generate_series(1, 1500) i;
ALTER TABLE t DROP COLUMN c;
VACUUM VERBOSE t;
INFO: statistics for "t":
total file size: 32768, total data size: 31372
total row count: 7030, stripe count: 6, average rows per stripe: 1171
block count: 11, containing data for dropped columns: 2, none compressed: 9, pglz compressed: 2
-- vacuum full should remove blocks for dropped columns
-- note that, a block will be stored in non-compressed for if compression
-- doesn't reduce its size.
SET cstore.compression TO "pglz";
VACUUM FULL t;
VACUUM VERBOSE t;
INFO: statistics for "t":
total file size: 16384, total data size: 15728
total row count: 7030, stripe count: 4, average rows per stripe: 1757
block count: 8, containing data for dropped columns: 0, none compressed: 2, pglz compressed: 6
DROP TABLE t;
-- Make sure we cleaned the metadata for t too
SELECT count(*) - :columnar_table_count FROM cstore.cstore_data_files;

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@ -0,0 +1,68 @@
Parsed test spec with 2 sessions
starting permutation: s1-insert s1-begin s1-insert s2-vacuum s1-commit s2-select
step s1-insert:
INSERT INTO test_vacuum_vs_insert SELECT i, 2 * i FROM generate_series(1, 3) i;
step s1-begin:
BEGIN;
step s1-insert:
INSERT INTO test_vacuum_vs_insert SELECT i, 2 * i FROM generate_series(1, 3) i;
s2: INFO: statistics for "test_vacuum_vs_insert":
total file size: 8192, total data size: 26
total row count: 3, stripe count: 1, average rows per stripe: 3
block count: 2, containing data for dropped columns: 0, none compressed: 2, pglz compressed: 0
s2: INFO: "test_vacuum_vs_insert": stopping truncate due to conflicting lock request
step s2-vacuum:
VACUUM VERBOSE test_vacuum_vs_insert;
step s1-commit:
COMMIT;
step s2-select:
SELECT * FROM test_vacuum_vs_insert;
a b
1 2
2 4
3 6
1 2
2 4
3 6
starting permutation: s1-insert s1-begin s1-insert s2-vacuum-full s1-commit s2-select
step s1-insert:
INSERT INTO test_vacuum_vs_insert SELECT i, 2 * i FROM generate_series(1, 3) i;
step s1-begin:
BEGIN;
step s1-insert:
INSERT INTO test_vacuum_vs_insert SELECT i, 2 * i FROM generate_series(1, 3) i;
step s2-vacuum-full:
VACUUM FULL VERBOSE test_vacuum_vs_insert;
<waiting ...>
step s1-commit:
COMMIT;
s2: INFO: vacuuming "public.test_vacuum_vs_insert"
s2: INFO: "test_vacuum_vs_insert": found 0 removable, 6 nonremovable row versions in 1 pages
DETAIL: 0 dead row versions cannot be removed yet.
CPU: user: 0.00 s, system: 0.00 s, elapsed: 0.00 s.
step s2-vacuum-full: <... completed>
step s2-select:
SELECT * FROM test_vacuum_vs_insert;
a b
1 2
2 4
3 6
1 2
2 4
3 6

6
expected/create.out Normal file
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@ -0,0 +1,6 @@
Parsed test spec with 1 sessions
starting permutation: s1a
step s1a:
CREATE EXTENSION cstore_fdw;

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@ -0,0 +1,46 @@
setup
{
CREATE TABLE test_vacuum_vs_insert (a int, b int) USING cstore_tableam;
}
teardown
{
DROP TABLE IF EXISTS test_vacuum_vs_insert CASCADE;
}
session "s1"
step "s1-begin"
{
BEGIN;
}
step "s1-insert"
{
INSERT INTO test_vacuum_vs_insert SELECT i, 2 * i FROM generate_series(1, 3) i;
}
step "s1-commit"
{
COMMIT;
}
session "s2"
step "s2-vacuum"
{
VACUUM VERBOSE test_vacuum_vs_insert;
}
step "s2-vacuum-full"
{
VACUUM FULL VERBOSE test_vacuum_vs_insert;
}
step "s2-select"
{
SELECT * FROM test_vacuum_vs_insert;
}
permutation "s1-insert" "s1-begin" "s1-insert" "s2-vacuum" "s1-commit" "s2-select"
permutation "s1-insert" "s1-begin" "s1-insert" "s2-vacuum-full" "s1-commit" "s2-select"

7
specs/create.spec Normal file
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@ -0,0 +1,7 @@
session "s1"
step "s1a"
{
CREATE EXTENSION cstore_fdw;
}
permutation "s1a"

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@ -41,6 +41,62 @@ SELECT stripe, attr, block, minimum_value IS NULL, maximum_value IS NULL FROM cs
-- Make sure we cleaned-up the transient table metadata after VACUUM FULL commands
SELECT count(*) - :columnar_table_count FROM cstore.cstore_data_files;
-- do this in a transaction so concurrent autovacuum doesn't interfere with results
BEGIN;
SAVEPOINT s1;
SELECT count(*) FROM t;
SELECT pg_size_pretty(pg_relation_size('t'));
INSERT INTO t SELECT i FROM generate_series(1, 10000) i;
SELECT pg_size_pretty(pg_relation_size('t'));
SELECT count(*) FROM t;
ROLLBACK TO SAVEPOINT s1;
-- not truncated by VACUUM or autovacuum yet (being in transaction ensures this),
-- so relation size should be same as before.
SELECT pg_size_pretty(pg_relation_size('t'));
COMMIT;
-- vacuum should truncate the relation to the usable space
VACUUM VERBOSE t;
SELECT pg_size_pretty(pg_relation_size('t'));
SELECT count(*) FROM t;
-- add some stripes with different compression types and create some gaps,
-- then vacuum to print stats
BEGIN;
SET cstore.block_row_count TO 1000;
SET cstore.stripe_row_count TO 2000;
SET cstore.compression TO "pglz";
SAVEPOINT s1;
INSERT INTO t SELECT i FROM generate_series(1, 1500) i;
ROLLBACK TO SAVEPOINT s1;
INSERT INTO t SELECT i / 5 FROM generate_series(1, 1500) i;
SET cstore.compression TO "none";
SAVEPOINT s2;
INSERT INTO t SELECT i FROM generate_series(1, 1500) i;
ROLLBACK TO SAVEPOINT s2;
INSERT INTO t SELECT i / 5 FROM generate_series(1, 1500) i;
COMMIT;
VACUUM VERBOSE t;
SELECT count(*) FROM t;
-- check that we report blocks with data for dropped columns
ALTER TABLE t ADD COLUMN c int;
INSERT INTO t SELECT 1, i / 5 FROM generate_series(1, 1500) i;
ALTER TABLE t DROP COLUMN c;
VACUUM VERBOSE t;
-- vacuum full should remove blocks for dropped columns
-- note that, a block will be stored in non-compressed for if compression
-- doesn't reduce its size.
SET cstore.compression TO "pglz";
VACUUM FULL t;
VACUUM VERBOSE t;
DROP TABLE t;
-- Make sure we cleaned the metadata for t too