PostgreSQL 8.3の新機能のうち、特にHOT更新による高速化について解説します。

1. 2007.DB
http://www.ospn.jp/osc2007.db/
PostgreSQL 8.3 Update
8.3
PostgreSQL / NTT OSS
2007.6.23
1

2. 8.1 8.3
autovacuum
8.1
fillfactor GIN
8.2
HOT XML autovacuum
8.3
2

3. 8.1 8.2
autovacuum
8.1
fillfactor GIN
8.2
HOT XML autovacuum
8.3
3

4. CPU
バ TPC-C(OLTP) CPU
ー 5
ジ 8.2
ョ 8.0
ン 8CPU
ご 4 8.1
と 8.2 NUMA
の
、
Ｃ 3
Ｐ
Ｕ
１
個 2 8.1 SMP
に 4CPU
対 (8CPU )
す 1
る 8.0
相 2CPU
対
性 0
能 1 2 4 8 12 16 20 24 28 32
core
Scaling PostgreSQL on SMP Architectures
Doug Tolbert (Unisys), PGCon 2007, Ottawa, 2007-05-24 4
http://www.pgcon.org/2007/schedule/events/16.en.html

5. • tsearch2
: SELECT isbn,title FROM books
WHERE fts @@ to_tsquery(‘word1 & word2’);
– GiST, GIN: 2
– ,
tsearch2 GiST GIN
GiST 112ms 280ms 176s 146MB
• → GiST
GIN 39ms 3344ms 532s 306MB
• → GIN
×0.35 ×11.94 ×3.02 ×2.10
•
Full-Text Search in PostgreSQL
Oleg Bartunov PGCon 2007, Ottawa, 2007/5/23 5
http://www.pgcon.org/2007/schedule/events/13.en.html

6. VACUUM
• UPDATE
–
–
VACUUM
6

7. PostgreSQL 8.3
1.
– HOT OLTP
2.
–
3.
– WAL
4. VACUUM
– VACUUM autovacuum
7

8. (1) 8.3
• HOT FillFactor
Fill Factor TPS
TPS
– 280
– pgbench
260
40%
240
•
220 40%UP!
–
200
– VACUUM
• VACUUM 180
160
HOT
• FillFactor 140
– 120 HOT
– 100%( ) 100
90~95% 70 75 80 85 90 95 100
• ALTER TABLE name Fill Factor (%)
SET (fillfactor=95);
pgbench -s400 (5GB)
NTT OSS Center
8

9. HOT (1)
• 8.2 UPDATE
ID
001 A 10 …
002 B 8→7
003 C 20
004 D 12
9

10. HOT (2)
• 8.2 UPDATE
ID
001 A 10
002 B 8
003 C 20 UPDATE
004 D 12
×2 002 B 7
(CPU)
×3
(I/O)
10

11. HOT (3)
• 8.3 HOT UPDATE
→ ID
1
001 A 10
002 B 8
UPDATE
Heap 002 B 7
Only 003 C 20
Tuple
004 D 12
HOT
×1
(CPU)
1/2
×1
(I/O) 1/3
11

12. HOT (4)
• 8.3 HOT UPDATE
HOT
ID VACUUM
001 A 10
002 B 6
UPDATE
002 B 7
003 C 20
004 D 12
HOT
×1
(CPU)
×1 VACUUM
(I/O)
12

13. HOT
• UPDATE
– DELETE+INSERT
•
–
–
•
– FillFactor
– VACUUM
VACUUM 13

14. PostgreSQL 8.3
1.
– HOT OLTP
2.
–
3.
– WAL
4. VACUUM
– VACUUM autovacuum
14

15. (2) 8.3
• (LDC)
EnterpriseDB Performance Testing 15
http://community.enterprisedb.com/ldc/

16. •
– (write)
– (fsync)
8.2
8.3
PostgreSQL
I/O
I/O
16

17. PostgreSQL 8.3
1.
– HOT OLTP
2.
–
3.
– WAL
4. VACUUM
– VACUUM autovacuum
17

18. (3) 8.3
•
– WAL I/O 1/2
BEGIN;
TRUNCATE t;
35%
COPY t FROM …;
0 20 40 60 80 COMMIT;
pgbench -i -s30 ( COPY )
NTT OSS Center
• ( )
–
• InfoFrame DB Maintenance (NEC)
• pg_bulkload ( , pgFoundry) 8.3
18

19. (4) 8.3 VACUUM
• autovacuum VACUUM
– (autovacuum_max_workers)
1
8.2 → VACUUM
8.3
A B
VACUUM
19

20. autovacuum
8.1
fillfactor GIN
8.2
HOT XML autovacuum
8.3
20

21. PostgreSQL 8.3
–
• HOT OLTP
–
• VACUUM, Background Writer ( )
–
• SQL/XML, , , etc.
21