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Have TRUNCATE update pgstat tuple counters

Browse Source 
This works by keeping a per-subtransaction record of the ins/upd/del
counters before the truncate, and then resetting them; this record is
useful to return to the previous state in case the truncate is rolled
back, either in a subtransaction or whole transaction.  The state is
propagated upwards as subtransactions commit.

When the per-table data is sent to the stats collector, a flag indicates
to reset the live/dead counters to zero as well.

Catalog version bumped due to the change in pgstat format.

Author: Alexander Shulgin
Discussion: 1007.1207238291@sss.pgh.pa.us
Discussion: 548F7D38.2000401@BlueTreble.com
Reviewed-by: Álvaro Herrera, Jim Nasby
This commit is contained in:
Alvaro Herrera
2015-02-20 12:10:01 -03:00
parent 5740be6d6e
commit d42358efb1
8 changed files with 374 additions and 3 deletions
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50
src/test/regress/expected/prepared_xacts.out
View File

@ -247,8 +247,58 @@ SELECT gid FROM pg_prepared_xacts;
-----
(0 rows)
CREATE TABLE pxtest5 (a SERIAL);
INSERT INTO pxtest5 DEFAULT VALUES;
SELECT * FROM pxtest5;
a
---
1
(1 row)
BEGIN TRANSACTION ISOLATION LEVEL SERIALIZABLE;
INSERT INTO pxtest5 DEFAULT VALUES;
INSERT INTO pxtest5 DEFAULT VALUES;
TRUNCATE pxtest5;
INSERT INTO pxtest5 DEFAULT VALUES;
PREPARE TRANSACTION 'trunc-and-pgstat';
SELECT pg_sleep(0.5);
pg_sleep
----------
(1 row)
SELECT n_tup_ins, n_tup_upd, n_tup_del, n_live_tup, n_dead_tup
FROM pg_stat_user_tables
WHERE relname='pxtest5';
n_tup_ins | n_tup_upd | n_tup_del | n_live_tup | n_dead_tup
-----------+-----------+-----------+------------+------------
1 | 0 | 0 | 1 | 0
(1 row)
COMMIT PREPARED 'trunc-and-pgstat';
SELECT pg_sleep(0.5);
pg_sleep
----------
(1 row)
SELECT n_tup_ins, n_tup_upd, n_tup_del, n_live_tup, n_dead_tup
FROM pg_stat_user_tables
WHERE relname='pxtest5';
n_tup_ins | n_tup_upd | n_tup_del | n_live_tup | n_dead_tup
-----------+-----------+-----------+------------+------------
2 | 0 | 0 | 1 | 0
(1 row)
SELECT * FROM pxtest5;
a
---
4
(1 row)
-- Clean up
DROP TABLE pxtest2;
DROP TABLE pxtest3; -- will still be there if prepared xacts are disabled
ERROR: table "pxtest3" does not exist
DROP TABLE pxtest4;
DROP TABLE pxtest5;

53
src/test/regress/expected/prepared_xacts_1.out
View File

@ -249,9 +249,62 @@ SELECT gid FROM pg_prepared_xacts;
-----
(0 rows)
CREATE TABLE pxtest5 (a SERIAL);
INSERT INTO pxtest5 DEFAULT VALUES;
SELECT * FROM pxtest5;
a
---
1
(1 row)
BEGIN TRANSACTION ISOLATION LEVEL SERIALIZABLE;
INSERT INTO pxtest5 DEFAULT VALUES;
INSERT INTO pxtest5 DEFAULT VALUES;
TRUNCATE pxtest5;
INSERT INTO pxtest5 DEFAULT VALUES;
PREPARE TRANSACTION 'trunc-and-pgstat';
ERROR: prepared transactions are disabled
HINT: Set max_prepared_transactions to a nonzero value.
SELECT pg_sleep(0.5);
pg_sleep
----------
(1 row)
SELECT n_tup_ins, n_tup_upd, n_tup_del, n_live_tup, n_dead_tup
FROM pg_stat_user_tables
WHERE relname='pxtest5';
n_tup_ins | n_tup_upd | n_tup_del | n_live_tup | n_dead_tup
-----------+-----------+-----------+------------+------------
3 | 0 | 0 | 1 | 2
(1 row)
COMMIT PREPARED 'trunc-and-pgstat';
ERROR: prepared transaction with identifier "trunc-and-pgstat" does not exist
SELECT pg_sleep(0.5);
pg_sleep
----------
(1 row)
SELECT n_tup_ins, n_tup_upd, n_tup_del, n_live_tup, n_dead_tup
FROM pg_stat_user_tables
WHERE relname='pxtest5';
n_tup_ins | n_tup_upd | n_tup_del | n_live_tup | n_dead_tup
-----------+-----------+-----------+------------+------------
3 | 0 | 0 | 1 | 2
(1 row)
SELECT * FROM pxtest5;
a
---
1
(1 row)
-- Clean up
DROP TABLE pxtest2;
ERROR: table "pxtest2" does not exist
DROP TABLE pxtest3; -- will still be there if prepared xacts are disabled
DROP TABLE pxtest4;
ERROR: table "pxtest4" does not exist
DROP TABLE pxtest5;

64
src/test/regress/expected/stats.out
View File

@ -62,6 +62,57 @@ begin
extract(epoch from clock_timestamp() - start_time);
end
$$ language plpgsql;
-- test effects of TRUNCATE on n_live_tup/n_dead_tup counters
CREATE TABLE trunc_stats_test(id serial);
CREATE TABLE trunc_stats_test1(id serial);
CREATE TABLE trunc_stats_test2(id serial);
CREATE TABLE trunc_stats_test3(id serial);
CREATE TABLE trunc_stats_test4(id serial);
-- check that n_live_tup is reset to 0 after truncate
INSERT INTO trunc_stats_test DEFAULT VALUES;
INSERT INTO trunc_stats_test DEFAULT VALUES;
INSERT INTO trunc_stats_test DEFAULT VALUES;
TRUNCATE trunc_stats_test;
-- test involving a truncate in a transaction; 4 ins but only 1 live
INSERT INTO trunc_stats_test1 DEFAULT VALUES;
INSERT INTO trunc_stats_test1 DEFAULT VALUES;
INSERT INTO trunc_stats_test1 DEFAULT VALUES;
UPDATE trunc_stats_test1 SET id = id + 10 WHERE id IN (1, 2);
DELETE FROM trunc_stats_test1 WHERE id = 3;
BEGIN;
UPDATE trunc_stats_test1 SET id = id + 100;
TRUNCATE trunc_stats_test1;
INSERT INTO trunc_stats_test1 DEFAULT VALUES;
COMMIT;
-- use a savepoint: 1 insert, 1 live
BEGIN;
INSERT INTO trunc_stats_test2 DEFAULT VALUES;
INSERT INTO trunc_stats_test2 DEFAULT VALUES;
SAVEPOINT p1;
INSERT INTO trunc_stats_test2 DEFAULT VALUES;
TRUNCATE trunc_stats_test2;
INSERT INTO trunc_stats_test2 DEFAULT VALUES;
RELEASE SAVEPOINT p1;
COMMIT;
-- rollback a savepoint: this should count 4 inserts and have 2
-- live tuples after commit (and 2 dead ones due to aborted subxact)
BEGIN;
INSERT INTO trunc_stats_test3 DEFAULT VALUES;
INSERT INTO trunc_stats_test3 DEFAULT VALUES;
SAVEPOINT p1;
INSERT INTO trunc_stats_test3 DEFAULT VALUES;
INSERT INTO trunc_stats_test3 DEFAULT VALUES;
TRUNCATE trunc_stats_test3;
INSERT INTO trunc_stats_test3 DEFAULT VALUES;
ROLLBACK TO SAVEPOINT p1;
COMMIT;
-- rollback a truncate: this should count 2 inserts and produce 2 dead tuples
BEGIN;
INSERT INTO trunc_stats_test4 DEFAULT VALUES;
INSERT INTO trunc_stats_test4 DEFAULT VALUES;
TRUNCATE trunc_stats_test4;
INSERT INTO trunc_stats_test4 DEFAULT VALUES;
ROLLBACK;
-- do a seqscan
SELECT count(*) FROM tenk2;
count
@ -92,6 +143,18 @@ SELECT wait_for_stats();
(1 row)
-- check effects
SELECT relname, n_tup_ins, n_tup_upd, n_tup_del, n_live_tup, n_dead_tup
FROM pg_stat_user_tables
WHERE relname like 'trunc_stats_test%' order by relname;
relname | n_tup_ins | n_tup_upd | n_tup_del | n_live_tup | n_dead_tup
-------------------+-----------+-----------+-----------+------------+------------
trunc_stats_test | 3 | 0 | 0 | 0 | 0
trunc_stats_test1 | 4 | 2 | 1 | 1 | 0
trunc_stats_test2 | 1 | 0 | 0 | 1 | 0
trunc_stats_test3 | 4 | 0 | 0 | 2 | 2
trunc_stats_test4 | 2 | 0 | 0 | 0 | 2
(5 rows)
SELECT st.seq_scan >= pr.seq_scan + 1,
st.seq_tup_read >= pr.seq_tup_read + cl.reltuples,
st.idx_scan >= pr.idx_scan + 1,
@ -119,4 +182,5 @@ FROM prevstats AS pr;
t
(1 row)
DROP TABLE trunc_stats_test, trunc_stats_test1, trunc_stats_test2, trunc_stats_test3, trunc_stats_test4;
-- End of Stats Test

27
src/test/regress/sql/prepared_xacts.sql
View File

@ -152,7 +152,34 @@ SELECT * FROM pxtest3;
-- There should be no prepared transactions
SELECT gid FROM pg_prepared_xacts;
CREATE TABLE pxtest5 (a SERIAL);
INSERT INTO pxtest5 DEFAULT VALUES;
SELECT * FROM pxtest5;
BEGIN TRANSACTION ISOLATION LEVEL SERIALIZABLE;
INSERT INTO pxtest5 DEFAULT VALUES;
INSERT INTO pxtest5 DEFAULT VALUES;
TRUNCATE pxtest5;
INSERT INTO pxtest5 DEFAULT VALUES;
PREPARE TRANSACTION 'trunc-and-pgstat';
SELECT pg_sleep(0.5);
SELECT n_tup_ins, n_tup_upd, n_tup_del, n_live_tup, n_dead_tup
FROM pg_stat_user_tables
WHERE relname='pxtest5';
COMMIT PREPARED 'trunc-and-pgstat';
SELECT pg_sleep(0.5);
SELECT n_tup_ins, n_tup_upd, n_tup_del, n_live_tup, n_dead_tup
FROM pg_stat_user_tables
WHERE relname='pxtest5';
SELECT * FROM pxtest5;
-- Clean up
DROP TABLE pxtest2;
DROP TABLE pxtest3; -- will still be there if prepared xacts are disabled
DROP TABLE pxtest4;
DROP TABLE pxtest5;

64
src/test/regress/sql/stats.sql
View File

@ -58,6 +58,64 @@ begin
end
$$ language plpgsql;
-- test effects of TRUNCATE on n_live_tup/n_dead_tup counters
CREATE TABLE trunc_stats_test(id serial);
CREATE TABLE trunc_stats_test1(id serial);
CREATE TABLE trunc_stats_test2(id serial);
CREATE TABLE trunc_stats_test3(id serial);
CREATE TABLE trunc_stats_test4(id serial);
-- check that n_live_tup is reset to 0 after truncate
INSERT INTO trunc_stats_test DEFAULT VALUES;
INSERT INTO trunc_stats_test DEFAULT VALUES;
INSERT INTO trunc_stats_test DEFAULT VALUES;
TRUNCATE trunc_stats_test;
-- test involving a truncate in a transaction; 4 ins but only 1 live
INSERT INTO trunc_stats_test1 DEFAULT VALUES;
INSERT INTO trunc_stats_test1 DEFAULT VALUES;
INSERT INTO trunc_stats_test1 DEFAULT VALUES;
UPDATE trunc_stats_test1 SET id = id + 10 WHERE id IN (1, 2);
DELETE FROM trunc_stats_test1 WHERE id = 3;
BEGIN;
UPDATE trunc_stats_test1 SET id = id + 100;
TRUNCATE trunc_stats_test1;
INSERT INTO trunc_stats_test1 DEFAULT VALUES;
COMMIT;
-- use a savepoint: 1 insert, 1 live
BEGIN;
INSERT INTO trunc_stats_test2 DEFAULT VALUES;
INSERT INTO trunc_stats_test2 DEFAULT VALUES;
SAVEPOINT p1;
INSERT INTO trunc_stats_test2 DEFAULT VALUES;
TRUNCATE trunc_stats_test2;
INSERT INTO trunc_stats_test2 DEFAULT VALUES;
RELEASE SAVEPOINT p1;
COMMIT;
-- rollback a savepoint: this should count 4 inserts and have 2
-- live tuples after commit (and 2 dead ones due to aborted subxact)
BEGIN;
INSERT INTO trunc_stats_test3 DEFAULT VALUES;
INSERT INTO trunc_stats_test3 DEFAULT VALUES;
SAVEPOINT p1;
INSERT INTO trunc_stats_test3 DEFAULT VALUES;
INSERT INTO trunc_stats_test3 DEFAULT VALUES;
TRUNCATE trunc_stats_test3;
INSERT INTO trunc_stats_test3 DEFAULT VALUES;
ROLLBACK TO SAVEPOINT p1;
COMMIT;
-- rollback a truncate: this should count 2 inserts and produce 2 dead tuples
BEGIN;
INSERT INTO trunc_stats_test4 DEFAULT VALUES;
INSERT INTO trunc_stats_test4 DEFAULT VALUES;
TRUNCATE trunc_stats_test4;
INSERT INTO trunc_stats_test4 DEFAULT VALUES;
ROLLBACK;
-- do a seqscan
SELECT count(*) FROM tenk2;
-- do an indexscan
@ -71,12 +129,17 @@ SELECT pg_sleep(1.0);
SELECT wait_for_stats();
-- check effects
SELECT relname, n_tup_ins, n_tup_upd, n_tup_del, n_live_tup, n_dead_tup
FROM pg_stat_user_tables
WHERE relname like 'trunc_stats_test%' order by relname;
SELECT st.seq_scan >= pr.seq_scan + 1,
st.seq_tup_read >= pr.seq_tup_read + cl.reltuples,
st.idx_scan >= pr.idx_scan + 1,
st.idx_tup_fetch >= pr.idx_tup_fetch + 1
FROM pg_stat_user_tables AS st, pg_class AS cl, prevstats AS pr
WHERE st.relname='tenk2' AND cl.relname='tenk2';
SELECT st.heap_blks_read + st.heap_blks_hit >= pr.heap_blks + cl.relpages,
st.idx_blks_read + st.idx_blks_hit >= pr.idx_blks + 1
FROM pg_statio_user_tables AS st, pg_class AS cl, prevstats AS pr
@ -85,4 +148,5 @@ SELECT st.heap_blks_read + st.heap_blks_hit >= pr.heap_blks + cl.relpages,
SELECT pr.snap_ts < pg_stat_get_snapshot_timestamp() as snapshot_newer
FROM prevstats AS pr;
DROP TABLE trunc_stats_test, trunc_stats_test1, trunc_stats_test2, trunc_stats_test3, trunc_stats_test4;
-- End of Stats Test