제 6회 엑셈 수요 세미나 자료 연구컨텐츠팀

제 6회 엑셈 수요 세미나 자료

EXEM seminar report no. 006 (2016.06.29)

Research & Contents Team

Table of Agenda

© Copyrights 2001~2016, EXEM CO.,LTD. All Rights Reserved.

01.

02.

03.

[MySQL] Page Dump 분석

[PostgreSQL] Vacuum의 거의 모든 것 (2차)

[MySQL] 통계정보 관리


01. [PostgreSQL] Vacuum의 거의 모든 것 (2차)

발표자: 연구컨텐츠팀 김숙진


목차

1차

1) Vacuum 정의 및 필요성2) Vacuum 실행 구조3) 표준 Vacuum VS Vacuum full (시나리오)

2차

1) dump로 보는 “표준 Vacuum VS Vacuum full”

[PostgreSQL] Vacuum의 거의 모든 것


1. Dump로 보는 “표준 Vacuum VS Vacuum full”

<표준 Vacuum과 Vacuum full 비교시나리오>

순서 command 순서 command

1. Database생성 create database vac; 9. 총사이즈확인 select pg_total_relation_size(‘myt’);

2. oid확인 oid2name | grep vac 10. myt 테이블에 vacuum 작업 vacuum myt;

3. 테이블생성 create table myt(id char(7)); 11. 총사이즈확인 select pg_total_relation_size(‘myt’);

4. pg_relation_path확인 select pg_relation_filepath(‘myt’); 12. myt 테이블에 200부터 11건삽입insert into myt select generate_series(200,210);

5. 총사이즈확인 select pg_total_relation_size(‘myt’); 13. 총사이즈확인 select pg_total_relation_size(‘myt’);

6. myt 테이블에 100건삽입insert into myt select generate_series(100,199);

14. myt 테이블에 vacuum full 작업 vauum full myt;


8. myt 테이블에서 id가 150이상이면삭제

delete from myt where id>=‘150’; 16. pg_relation_path확인 select pg_relation_filepath(‘myt’);



[postgres@153_40 base]$ createdb vac[postgres@153_40 base]$ oid2name | grep vac

1254094 vac pg_default[postgres@153_40 base]$ cd 1254094/[postgres@153_40 1254094]$ psql -d vac

(postgres@[local]:5432) [vac] > \! pwd/usr/local/pgsql/data/base/1254094

(postgres@[local]:5432) [vac] > \! ls | head -51273512735_fsm12735_vm1273712737_fsm

(postgres@[local]:5432) [vac] > create table myt(id char(7));CREATE TABLE(postgres@[local]:5432) [vac] > select pg_relation_filepath('myt');pg_relation_filepath

----------------------base/ 1254094/1254095

(1 row)

(postgres@[local]:5432) [vac] > \! ls -lt 123*-rw------- 1 postgres postgres 0 Jun 21 16:10 1254094

(postgres@[local]:5432) [vac] > select pg_total_relation_size('myt');pg_total_relation_size

------------------------0

(1 row)

12

34

5

<시나리오>


(postgres@[local]:5432) [vac] > insert into myt select generate_series(100,199);INSERT 0 100(postgres@[local]:5432) [vac] > select pg_total_relation_size('myt');pg_total_relation_size

------------------------8192

(1 row)

(postgres@[local]:5432) [vac] > \! ls –l 1254095-rw------- 1 postgres postgres 8192 Jun 24 13:59 /usr/local/pgsql/data/base/1254094/1254095


6

7

<시나리오> <dump>000000 07 00 00 00 08 0f 0b 1a 00 00 00 00 a8 01 80 13 >................<

…

0001b0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >................<

001380 69 31 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >i1..............<

001390 64 00 01 00 02 08 18 00 11 31 39 39 20 20 20 20 >d........199 <

0013a0 69 31 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >i1..............<

0013b0 63 00 01 00 02 08 18 00 11 31 39 38 20 20 20 20 >c........198 <

…

001980 69 31 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >i1..............<

001990 34 00 01 00 02 08 18 00 11 31 35 31 20 20 20 20 >4........151 <

0019a0 69 31 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >i1..............<

0019b0 33 00 01 00 02 08 18 00 11 31 35 30 20 20 20 20 >3........150 <

…

001fe0 69 31 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >i1..............<

001ff0 01 00 01 00 02 08 18 00 11 31 30 30 20 20 20 20 >.........100 <

100~199Insert 결과

insert into myt select generate_series(100,199); Page Header +

Item Pointer

Tuple


(postgres@[local]:5432) [vac] > delete from myt where id>='150';DELETE 50(postgres@[local]:5432) [vac] > select pg_total_relation_size('myt');pg_total_relation_size

------------------------8192

(1 row)


8

9

000000 07 00 00 00 08 0f 0b 1a 00 00 00 00 a8 01 80 13 >................<

…

0001b0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >................<

001380 69 31 00 00 6b 31 00 00 00 00 00 00 00 00 00 00 >i1..k1..........<

001390 64 00 01 20 02 01 18 00 11 31 39 39 20 20 20 20 >d.. .....199 <

0013a0 69 31 00 00 6b 31 00 00 00 00 00 00 00 00 00 00 >i1..k1..........<

0013b0 63 00 01 20 02 01 18 00 11 31 39 38 20 20 20 20 >c.. .....198 <

…

001980 69 31 00 00 6b 31 00 00 00 00 00 00 00 00 00 00 >i1..k1..........<

001990 34 00 01 20 02 01 18 00 11 31 35 31 20 20 20 20 >4.. .....151 <

0019a0 69 31 00 00 6b 31 00 00 00 00 00 00 00 00 00 00 >i1..k1..........<

0019b0 33 00 01 20 02 01 18 00 11 31 35 30 20 20 20 20 >3.. .....150 <

…

001fe0 69 31 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >i1..............<

001ff0 01 00 01 00 02 08 18 00 11 31 30 30 20 20 20 20 >.........100 <

<dump><시나리오>

delete 후, 150부터 199까지 xmax가 표시됨

100~149

delete from myt where id>=‘150’; Page Header +

Item Pointer

Tuple


(postgres@[local]:5432) [vac] > vacuum myt;VACUUM

(postgres@[local]:5432) [vac] > select pg_total_relation_size('myt');pg_total_relation_size

------------------------40960

(1 row)

(postgres@[local]:5432) [vac] > \! ls –l 1254095-rw------- 1 postgres postgres 8192 Jun 24 14:00/usr/local/pgsql/data/base/1254094/1254095-rw------- 1 postgres postgres 24576 Jun 24 14:00 /usr/local/pgsql/data/base/1254094/1254095_fsm-rw------- 1 postgres postgres 8192 Jun 24 14:00 /usr/local/pgsaql/data/base/1254094/1254095_vm


10

11

000000 07 00 00 00 08 0f 0b 1a 00 00 00 00 a8 01 80 13 >................<

…

0000e0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >................<

001380 69 31 00 00 6b 31 00 00 00 00 00 00 00 00 00 00 >i1..k1..........<

001390 64 00 01 20 02 01 18 00 11 31 39 39 20 20 20 20 >d.. .....199 <

0013a0 69 31 00 00 6b 31 00 00 00 00 00 00 00 00 00 00 >i1..k1..........<

0013b0 63 00 01 20 02 01 18 00 11 31 39 38 20 20 20 20 >c.. .....198 <

…

001980 69 31 00 00 6b 31 00 00 00 00 00 00 00 00 00 00 >i1..k1..........<

001990 34 00 01 20 02 01 18 00 11 31 35 31 20 20 20 20 >4.. .....151 <

0019a0 69 31 00 00 6b 31 00 00 00 00 00 00 00 00 00 00 >i1..k1..........<

0019b0 33 00 01 20 02 01 18 00 11 31 35 30 20 20 20 20 >3.. .....150 <

…

001fe0 69 31 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >i1..............<

001ff0 01 00 01 00 02 08 18 00 11 31 30 30 20 20 20 20 >.........100 <

50건에 대한 Item Pointer 삭제


vacuum myt;


(postgres@[local]:5432) [vac] > insert into myt select generate_series(200,210);INSERT 0 11(postgres@[local]:5432) [vac] > select pg_total_relation_size('myt');pg_total_relation_size

------------------------40960

(1 row)

(postgres@[local]:5432) [vac] > \! ls –l 1254095-rw------- 1 postgres postgres 8192 Jun 24 14:01 /usr/local/pgsql/data/base/1254094/1254095-rw------- 1 postgres postgres 24576 Jun 24 14:01 /usr/local/pgsql/data/base/1254094/1254095_fsm-rw------- 1 postgres postgres 8192 Jun 24 14:01 /usr/local/pgsql/data/base/1254094/1254095_vm


13

12

000000 07 00 00 00 08 0f 0b 1a 00 00 00 00 a8 01 80 13 >................<

…

000110 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >................<

001380 69 31 00 00 6b 31 00 00 00 00 00 00 00 00 00 00 >i1..k1..........<

001390 64 00 01 20 02 01 18 00 11 31 39 39 20 20 20 20 >d.. .....199 <

…

001840 69 31 00 00 6b 31 00 00 00 00 00 00 00 00 00 00 >i1..k1..........<

001850 3e 00 01 20 02 05 18 00 11 31 36 31 20 20 20 20 >>.. .....161 <

001860 6c 31 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >l1..............<

001870 3d 00 01 00 02 08 18 00 11 32 31 30 20 20 20 20 >=........210 <

…

0019a0 6c 31 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >l1..............<

0019b0 33 00 01 00 02 08 18 00 11 32 30 30 20 20 20 20 >3........200 <

0019c0 69 31 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >i1..............<

0019d0 32 00 01 00 02 09 18 00 11 31 34 39 20 20 20 20 >2........149 <

…

001fe0 69 31 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >i1..............<

001ff0 01 00 01 00 02 08 18 00 11 31 30 30 20 20 20 20 >.........100 <


200~210이 delete 된150 자리부터 reuse 됨

insert into myt select generate_series(200,210);11건에 대한 Item Pointer 추가


000000 07 00 00 00 50 60 0b 1a 00 00 05 00 a8 01 c0 19 >....P`..........<

000010 00 20 04 20 00 00 00 00 e0 9f 40 00 c0 9f 40 00 >. . ......@...@.<

000020 a0 9f 40 00 80 9f 40 00 60 9f 40 00 40 9f 40 00 >..@...@.`.@.@.@.<

000030 20 9f 40 00 00 9f 40 00 e0 9e 40 00 c0 9e 40 00 > .@...@...@...@.<

000040 a0 9e 40 00 80 9e 40 00 60 9e 40 00 40 9e 40 00 >..@...@.`.@.@.@.<

000050 20 9e 40 00 00 9e 40 00 e0 9d 40 00 c0 9d 40 00 > .@...@...@...@.<

000060 a0 9d 40 00 80 9d 40 00 60 9d 40 00 40 9d 40 00 >..@...@.`.@.@.@.<

000070 20 9d 40 00 00 9d 40 00 e0 9c 40 00 c0 9c 40 00 > .@...@...@...@.<

000080 a0 9c 40 00 80 9c 40 00 60 9c 40 00 40 9c 40 00 >..@...@.`.@.@.@.<

000090 20 9c 40 00 00 9c 40 00 e0 9b 40 00 c0 9b 40 00 > .@...@...@...@.<

0000a0 a0 9b 40 00 80 9b 40 00 60 9b 40 00 40 9b 40 00 >..@...@.`.@.@.@.<

0000b0 20 9b 40 00 00 9b 40 00 e0 9a 40 00 c0 9a 40 00 > .@...@...@...@.<

0000c0 a0 9a 40 00 80 9a 40 00 60 9a 40 00 40 9a 40 00 >..@...@.`.@.@.@.<

0000d0 20 9a 40 00 00 9a 40 00 e0 99 40 00 c0 99 40 00 > .@...@...@...@.<

0000e0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >................<

000000 07 00 00 00 78 aa 0b 1a 00 00 01 00 a8 01 60 18 >....x.........`.<

000010 00 20 04 20 00 00 00 00 e0 9f 40 00 c0 9f 40 00 >. . ......@...@.<

000020 a0 9f 40 00 80 9f 40 00 60 9f 40 00 40 9f 40 00 >..@...@.`.@.@.@.<

000030 20 9f 40 00 00 9f 40 00 e0 9e 40 00 c0 9e 40 00 > .@...@...@...@.<

000040 a0 9e 40 00 80 9e 40 00 60 9e 40 00 40 9e 40 00 >..@...@.`.@.@.@.<

000050 20 9e 40 00 00 9e 40 00 e0 9d 40 00 c0 9d 40 00 > .@...@...@...@.<

000060 a0 9d 40 00 80 9d 40 00 60 9d 40 00 40 9d 40 00 >..@...@.`.@.@.@.<

000070 20 9d 40 00 00 9d 40 00 e0 9c 40 00 c0 9c 40 00 > .@...@...@...@.<

000080 a0 9c 40 00 80 9c 40 00 60 9c 40 00 40 9c 40 00 >..@...@.`.@.@.@.<

000090 20 9c 40 00 00 9c 40 00 e0 9b 40 00 c0 9b 40 00 > .@...@...@...@.<

0000a0 a0 9b 40 00 80 9b 40 00 60 9b 40 00 40 9b 40 00 >..@...@.`.@.@.@.<

0000b0 20 9b 40 00 00 9b 40 00 e0 9a 40 00 c0 9a 40 00 > .@...@...@...@.<

0000c0 a0 9a 40 00 80 9a 40 00 60 9a 40 00 40 9a 40 00 >..@...@.`.@.@.@.<

0000d0 20 9a 40 00 00 9a 40 00 e0 99 40 00 c0 99 40 00 > .@...@...@...@.<

0000e0 a0 99 40 00 80 99 40 00 60 99 40 00 40 99 40 00 >..@...@.`.@.@.@.<

0000f0 20 99 40 00 00 99 40 00 e0 98 40 00 c0 98 40 00 > .@...@...@...@.<

000100 a0 98 40 00 80 98 40 00 60 98 40 00 00 00 00 00 >..@...@.`.@.....<

000110 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >................<

<Page Header + Item Pointer>

Item Pointer11건 추가됨

insert into myt select generate_series(200,210);


11건 insert

Page Header


000000 07 00 00 00 78 aa 0b 1a 00 00 01 00 a8 01 60 18 >....x.........`.<

000010 00 20 04 20 00 00 00 00 e0 9f 40 00 c0 9f 40 00 >. . ......@...@.<

000020 a0 9f 40 00 80 9f 40 00 60 9f 40 00 40 9f 40 00 >..@...@.`.@.@.@.<

000030 20 9f 40 00 00 9f 40 00 e0 9e 40 00 c0 9e 40 00 > .@...@...@...@.<

000040 a0 9e 40 00 80 9e 40 00 60 9e 40 00 40 9e 40 00 >..@...@.`.@.@.@.<

000050 20 9e 40 00 00 9e 40 00 e0 9d 40 00 c0 9d 40 00 > .@...@...@...@.<

000060 a0 9d 40 00 80 9d 40 00 60 9d 40 00 40 9d 40 00 >..@...@.`.@.@.@.<

000070 20 9d 40 00 00 9d 40 00 e0 9c 40 00 c0 9c 40 00 > .@...@...@...@.<

000080 a0 9c 40 00 80 9c 40 00 60 9c 40 00 40 9c 40 00 >..@...@.`.@.@.@.<

000090 20 9c 40 00 00 9c 40 00 e0 9b 40 00 c0 9b 40 00 > .@...@...@...@.<

0000a0 a0 9b 40 00 80 9b 40 00 60 9b 40 00 40 9b 40 00 >..@...@.`.@.@.@.<

0000b0 20 9b 40 00 00 9b 40 00 e0 9a 40 00 c0 9a 40 00 > .@...@...@...@.<

0000c0 a0 9a 40 00 80 9a 40 00 60 9a 40 00 40 9a 40 00 >..@...@.`.@.@.@.<

0000d0 20 9a 40 00 00 9a 40 00 e0 99 40 00 c0 99 40 00 > .@...@...@...@.<

0000e0 a0 99 40 00 80 99 40 00 60 99 40 00 40 99 40 00 >..@...@.`.@.@.@.<

0000f0 20 99 40 00 00 99 40 00 e0 98 40 00 c0 98 40 00 > .@...@...@...@.<

000100 a0 98 40 00 80 98 40 00 60 98 40 00 00 00 00 00 >..@...@.`.@.....<

000110 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >................<

<Page Header + Item Pointer>


001860 6c 31 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >l1..............<

001870 3d 00 01 00 02 08 18 00 11 32 31 30 20 20 20 20 >=........210 <

001880 6c 31 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >l1..............<

001890 3c 00 01 00 02 08 18 00 11 32 30 39 20 20 20 20 ><........209 <

0018a0 6c 31 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >l1..............<

0018b0 3b 00 01 00 02 08 18 00 11 32 30 38 20 20 20 20 >;........208 <

0018c0 6c 31 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >l1..............<

0018d0 3a 00 01 00 02 08 18 00 11 32 30 37 20 20 20 20 >:........207 <

0018e0 6c 31 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >l1..............<

0018f0 39 00 01 00 02 08 18 00 11 32 30 36 20 20 20 20 >9........206 <

001900 6c 31 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >l1..............<

001910 38 00 01 00 02 08 18 00 11 32 30 35 20 20 20 20 >8........205 <

001920 6c 31 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >l1..............<

001930 37 00 01 00 02 08 18 00 11 32 30 34 20 20 20 20 >7........204 <

001940 6c 31 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >l1..............<

001950 36 00 01 00 02 08 18 00 11 32 30 33 20 20 20 20 >6........203 <

001960 6c 31 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >l1..............<

001970 35 00 01 00 02 08 18 00 11 32 30 32 20 20 20 20 >5........202 <

001980 6c 31 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >l1..............<

001990 34 00 01 00 02 08 18 00 11 32 30 31 20 20 20 20 >4........201 <

0019a0 6c 31 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >l1..............<

0019b0 33 00 01 00 02 08 18 00 11 32 30 30 20 20 20 20 >3........200 <

<Tuple> 새롭게 Insert된 데이터


60 98 40 00

00 40 98 60

뒤세자리 860이Tuple 첫항목과동일

새롭게 Insert된 데이터


(postgres@[local]:5432) [vac] > vacuum full myt;VACUUM(postgres@[local]:5432) [vac] > select pg_total_relation_size('myt');pg_total_relation_size

------------------------8192

(1 row)

(postgres@[local]:5432) [vac] > select pg_relation_filepath('myt');pg_relation_filepath

----------------------/base/1254094/1254098(1 row)

원래 pg_relation_filepathbase/ 1254094/1254095


1415

16

<시나리오>000000 07 00 00 00 08 0f 0b 1a 00 00 00 00 a8 01 80 13 >................<

…

000110 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >................<

001860 6c 31 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >l1..............<

001870 3d 00 01 00 02 0b 18 00 11 32 31 30 20 20 20 20 >=........210 <

001880 6c 31 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >l1..............<

001890 3c 00 01 00 02 0b 18 00 11 32 30 39 20 20 20 20 ><........209 <

…

0019a0 6c 31 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >l1..............<

0019b0 33 00 01 00 02 0b 18 00 11 32 30 30 20 20 20 20 >3........200 <

0019c0 69 31 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >i1..............<

0019d0 32 00 01 00 02 0b 18 00 11 31 34 39 20 20 20 20 >2........149 <

…

001fe0 69 31 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >i1..............<

001ff0 01 00 01 00 02 0b 18 00 11 31 30 30 20 20 20 20 >.........100 <

<dump>

200~210 삽입된 튜플을제외하고, 그 뒤에161~199 삭제

vauum full myt; Page Header +

Item Pointer

200~210

Tuple

100~149



Page Header +

Item PointerTuple

insert into myt select generate_series(100,199);100건에대한 Page Header와

Item Pointer 생성100건에대한 tuple 생성

delete from myt where id>=‘150’; 변경 X delete 후, 150부터 199까지 xmax 표시

vacuum myt; 50건에대한 Item Pointer 삭제 변경 X

insert into myt select generate_series(200,210); 11건에대한 Item Pointer 생성 200~210이 150 자리부터 reuse 됨

vauum full myt; 변경 X200~210 삽입된 튜플을 제외하고,

그 뒤에 161~199 삭제


Questions

1. DB 생성 후, 무엇이 생성되는가?

2. Vacuum Full하면 새로운 파일이 생성되는데, 이전의 파일은 계속 있는가?

3. Delete 후 바로 Insert 하면, Delete 된 튜플에 Insert data가 삽입되는가?


Questions

12735 12755 12775 12793_fsm 12809 12825_fsm 12845 12862_vm 12910 12925 12949 12968_vm 12988_fsm

12735_fsm 12756 12776 12793_vm 12809_fsm 12825_vm 12846 12864 12910_fsm 12925_fsm 12953 12970 12988_vm

12735_vm 12757 12776_fsm 12795 12809_vm 12827 12847 12865 12910_vm 12925_vm 12953_fsm 12972 12990

12737 12757_fsm 12776_vm 12796 12811 12828 12847_fsm 12866 12912 12927 12953_vm 12973 12992

12737_fsm 12757_vm 12778 12797 12812 12828_fsm 12847_vm 12866_fsm 12913 12928 12955 12973_fsm 12993

12737_vm 12759 12780 12797_fsm 12813 12828_vm 12849 12866_vm 12913_fsm 12929 12956 12973_vm 12995

12739 12761 12781 12797_vm 12814 12830 12851 12868 12913_vm 12931 12957 12975 12997

12740 12762 12782 12799 12814_fsm 12830_fsm 12852 12869 12915 12932 12957_fsm 12977 pg_filenode.map

12741 12763 12783 12800 12814_vm 12830_vm 12853 12870 12916 12933 12957_vm 12978 PG_VERSION

12741_fsm 12764 12784 12801 12816 12832 12853_fsm 12871 12917 12935 12959 12978_fsm

12741_vm 12764_fsm 12785 12801_fsm 12817 12833 12853_vm 12871_fsm 12917_fsm 12936 12960 12978_vm

12743 12764_vm 12787 12801_vm 12818 12834 12855 12871_vm 12917_vm 12937 12962 12980

12744 12766 12788 12803 12818_fsm 12835 12856 12873 12919 12939 12963 12982

12749 12767 12789 12804 12818_vm 12837 12857 12874 12920 12940 12963_fsm 12983

12751 12768 12789_fsm 12805 12820 12839 12859 12906 12921 12942 12963_vm 12983_fsm

12752 12769 12789_vm 12805_fsm 12821 12840 12860 12906_fsm 12921_fsm 12943 12965 12983_vm

12753 12771 12791 12805_vm 12822 12841 12861 12906_vm 12921_vm 12944 12967 12985

12753_fsm 12773 12792 12807 12824 12842 12862 12908 12923 12946 12968 12987

12753_vm 12774 12793 12808 12825 12843 12862_fsm 12909 12924 12948 12968_fsm 12988

DB 생성시생성되는파일들select * from pg_class where relfilenode='12735’;

1. DB 생성 후, 무엇이 생성되는가?


Questions


[postgres@153_40 1262281]$ ls

1262282 12753 12771 12791 12805_vm 12822 12841 12861 12906_vm 12921_vm 12944 12967 12985

1262282_fsm 12753_fsm 12773 12792 12807 12824 12842 12862 12908 12923 12946 12968 12987

1262282_vm 12753_vm 12774 12793 12808 12825 12843 12862_fsm 12909 12924 12948 12968_fsm 12988

12735 12755 12775 12793_fsm 12809 12825_fsm 12845 12862_vm 12910 12925 12949 12968_vm 12988_fsm


12735_vm 12757 12776_fsm 12795 12809_vm 12827 12847 12865 12910_vm 12925_vm 12953_fsm 12972 12990

12737 12757_fsm 12776_vm 12796 12811 12828 12847_fsm 12866 12912 12927 12953_vm 12973 12992


12737_vm 12759 12780 12797_fsm 12813 12828_vm 12849 12866_vm 12913_fsm 12929 12956 12973_vm 12995

12739 12761 12781 12797_vm 12814 12830 12851 12868 12913_vm 12931 12957 12975 12997


12741 12763 12783 12800 12814_vm 12830_vm 12853 12870 12916 12933 12957_vm 12978 pg_internal.init

12741_fsm 12764 12784 12801 12816 12832 12853_fsm 12871 12917 12935 12959 12978_fsm PG_VERSION


12743 12764_vm 12787 12801_vm 12818 12834 12855 12871_vm 12917_vm 12937 12962 12980

12744 12766 12788 12803 12818_fsm 12835 12856 12873 12919 12939 12963 1298212749 12767 12789 12804 12818_vm 12837 12857 12874 12920 12940 12963_fsm 12983

12751 12768 12789_fsm 12805 12820 12839 12859 12906 12921 12942 12963_vm 12983_fsm

12752 12769 12789_vm 12805_fsm 12821 12840 12860 12906_fsm 12921_fsm 12943 12965 12983_vm

<표준 Vacuum한 상태>


Questions


[postgres@153_40 1262281]$ ls

1262285 12753_vm 12774 12793 12808 12825 12843 12862_fsm 12909 12924 12948 12968_fsm 12988

12735 12755 12775 12793_fsm 12809 12825_fsm 12845 12862_vm 12910 12925 12949 12968_vm 12988_fsm


12735_vm 12757 12776_fsm 12795 12809_vm 12827 12847 12865 12910_vm 12925_vm 12953_fsm 12972 12990

12737 12757_fsm 12776_vm 12796 12811 12828 12847_fsm 12866 12912 12927 12953_vm 12973 12992


12737_vm 12759 12780 12797_fsm 12813 12828_vm 12849 12866_vm 12913_fsm 12929 12956 12973_vm 12995

12739 12761 12781 12797_vm 12814 12830 12851 12868 12913_vm 12931 12957 12975 12997


12741 12763 12783 12800 12814_vm 12830_vm 12853 12870 12916 12933 12957_vm 12978 pg_internal.init

12741_fsm 12764 12784 12801 12816 12832 12853_fsm 12871 12917 12935 12959 12978_fsm PG_VERSION


12743 12764_vm 12787 12801_vm 12818 12834 12855 12871_vm 12917_vm 12937 12962 12980

12744 12766 12788 12803 12818_fsm 12835 12856 12873 12919 12939 12963 12982

12749 12767 12789 12804 12818_vm 12837 12857 12874 12920 12940 12963_fsm 12983

12751 12768 12789_fsm 12805 12820 12839 12859 12906 12921 12942 12963_vm 12983_fsm

12752 12769 12789_vm 12805_fsm 12821 12840 12860 12906_fsm 12921_fsm 12943 12965 12983_vm

12753 12771 12791 12805_vm 12822 12841 12861 12906_vm 12921_vm 12944 12967 12985

12753_fsm 12773 12792 12807 12824 12842 12862 12908 12923 12946 12968 12987

이전파일은사라짐

<Vacuum Full한 상태>


Questions

3. Delete 후 바로 Insert 하면, Delete 된 튜플에 Insert data가 삽입되는가?

순서 command 순서 command

1. Database생성 create database vac; 9. 총사이즈확인 select pg_total_relation_size(‘myt’);

2. oid확인 oid2name | grep vac 10. myt 테이블에 vacuum 작업 vacuum myt;

3. 테이블생성 create table myt(id char(7)); 11. 총사이즈확인 select pg_total_relation_size(‘myt’);

4. pg_relation_path확인 select pg_relation_filepath(‘myt’); 12. myt 테이블에 210부터 51건삽입insert into myt select generate_series(210,260);


6. myt 테이블에 100건삽입insert into myt select generate_series(100,199);

14. myt 테이블에 vacuum full 작업 vauum full myt;


8. myt 테이블에서 id가 150이상이면삭제

delete from myt where id>=‘150’; 16. pg_relation_path확인 select pg_relation_filepath(‘myt’);



Questions


000000 07 00 00 00 38 5e 24 1a 00 00 00 00 a8 01 80 13 >....8^$.........<

…

0001b0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >................<

001380 b7 31 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >.1..............<

001390 64 00 01 00 02 08 18 00 11 31 39 39 20 20 20 20 >d........199 <

0013a0 b7 31 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >.1..............<

0013b0 63 00 01 00 02 08 18 00 11 31 39 38 20 20 20 20 >c........198 <

…

001980 b7 31 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >.1..............<

001990 34 00 01 00 02 08 18 00 11 31 35 31 20 20 20 20 >4........151 <

0019a0 b7 31 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >.1..............<

0019b0 33 00 01 00 02 08 18 00 11 31 35 30 20 20 20 20 >3........150 <

…

001fe0 b7 31 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >.1..............<

001ff0 01 00 01 00 02 08 18 00 11 31 30 30 20 20 20 20 >.........100 <

Page Header +

Item Pointer

100~199Insert결과

Tuple

* 실제 Dump를옮겨놓은엑셀파일http://cafe.naver.com/playexem/332

http://cafe.naver.com/playexem/332


Questions

delete from myt where id>=‘150’;

000000 07 00 00 00 a8 79 24 1a 00 00 00 00 a8 01 80 13 >.....y$.........<

…

0001b0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >................<

001380 b7 31 00 00 b8 31 00 00 00 00 00 00 00 00 00 00 >.1...1..........<

001390 64 00 01 20 02 01 18 00 11 31 39 39 20 20 20 20 >d.. .....199 <

0013a0 b7 31 00 00 b8 31 00 00 00 00 00 00 00 00 00 00 >.1...1..........<

0013b0 63 00 01 20 02 01 18 00 11 31 39 38 20 20 20 20 >c.. .....198 <

…

001980 b7 31 00 00 b8 31 00 00 00 00 00 00 00 00 00 00 >.1...1..........<

001990 34 00 01 20 02 01 18 00 11 31 35 31 20 20 20 20 >4.. .....151 <

0019a0 b7 31 00 00 b8 31 00 00 00 00 00 00 00 00 00 00 >.1...1..........<

0019b0 33 00 01 20 02 01 18 00 11 31 35 30 20 20 20 20 >3.. .....150 <

…

001fe0 b7 31 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >.1..............<

001ff0 01 00 01 00 02 09 18 00 11 31 30 30 20 20 20 20 >.........100 <

Delete 후 150부터199까지 xmax 표시

Page Header +

Item Pointer

Tuple


Questions


000000 07 00 00 00 a8 79 24 1a 00 00 00 00 a8 01 80 13 >.....y$.........<

…

0001a0 a0 93 40 00 80 93 40 00 60 93 40 00 40 93 40 00 >..@...@.`.@.@.@.<

0001b0 20 93 40 00 00 93 40 00 e0 92 40 00 c0 92 40 00 > .@...@...@...@.<

0001c0 a0 92 40 00 80 92 40 00 60 92 40 00 40 92 40 00 >..@...@.`.@.@.@.<

0001d0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >................<

001240 b9 31 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >.1..............<

001250 6e 00 01 00 02 08 18 00 11 32 30 39 20 20 20 20 >n........209 <

001240 b9 31 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >.1..............<

001250 6e 00 01 00 02 08 18 00 11 32 30 39 20 20 20 20 >n........209 <

…

001360 b9 31 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >.1..............<

001370 65 00 01 00 02 08 18 00 11 32 30 30 20 20 20 20 >e........200 <

001380 b7 31 00 00 b8 31 00 00 00 00 00 00 00 00 00 00 >.1...1..........<

001390 64 00 01 20 02 01 18 00 11 31 39 39 20 20 20 20 >d.. .....199 <

001980 b7 31 00 00 b8 31 00 00 00 00 00 00 00 00 00 00 >.1...1..........<

001990 34 00 01 20 02 01 18 00 11 31 35 31 20 20 20 20 >4.. .....151 <

0019a0 b7 31 00 00 b8 31 00 00 00 00 00 00 00 00 00 00 >.1...1..........<

0019b0 33 00 01 20 02 01 18 00 11 31 35 30 20 20 20 20 >3.. .....150 <

0019c0 b7 31 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >.1..............<

0019d0 32 00 01 00 02 09 18 00 11 31 34 39 20 20 20 20 >2........149 <

…

001fc0 b7 31 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >.1..............<

001fd0 02 00 01 00 02 09 18 00 11 31 30 31 20 20 20 20 >.........101 <

001fe0 b7 31 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >.1..............<

001ff0 01 00 01 00 02 09 18 00 11 31 30 30 20 20 20 20 >.........100 <

새로 Insert 된 10건의Item Pointer

10건을 insert 했을때,

• 10건에대한 Item Pointer 생성• Tuple에서는 delete된튜플위로생성

Delete 된 튜플위에 새로운 튜플 생성


Questions

vacuum myt;

000000 07 00 00 00 58 96 24 1a 00 00 05 00 d0 01 80 18 >....X.$.........<

…

0000e0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >................<

…

0001a0 00 00 00 00 00 00 00 00 a0 99 40 00 80 99 40 00 >..........@...@.<

0001b0 60 99 40 00 40 99 40 00 20 99 40 00 00 99 40 00 >`.@.@.@. .@...@.<

0001c0 e0 98 40 00 c0 98 40 00 a0 98 40 00 80 98 40 00 >..@...@...@...@.<

0001d0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >................<

001240 b9 31 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >.1..............<

001250 6e 00 01 00 02 09 18 00 11 32 30 39 20 20 20 20 >n........209 <

001260 b9 31 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >.1..............<

001270 6d 00 01 00 02 09 18 00 11 32 30 38 20 20 20 20 >m........208 <

…

001360 b9 31 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >.1..............<

001370 65 00 01 00 02 08 18 00 11 32 30 30 20 20 20 20 >e........200 <

001380 b7 31 00 00 b8 31 00 00 00 00 00 00 00 00 00 00 >.1...1..........<

001390 64 00 01 20 02 01 18 00 11 31 39 39 20 20 20 20 >d.. .....199 <

…

001860 b7 31 00 00 b8 31 00 00 00 00 00 00 00 00 00 00 >.1...1..........<

001870 3d 00 01 20 02 05 18 00 11 31 36 30 20 20 20 20 >=.. .....160 <

001880 b9 31 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >.1..............<

001890 6e 00 01 00 02 09 18 00 11 32 30 39 20 20 20 20 >n........209 <

0018a0 b9 31 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >.1..............<

0018b0 6d 00 01 00 02 09 18 00 11 32 30 38 20 20 20 20 >m........208 <

…

0019a0 b9 31 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >.1..............<

0019b0 65 00 01 00 02 09 18 00 11 32 30 30 20 20 20 20 >e........200 <

0019c0 b7 31 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >.1..............<

0019d0 32 00 01 00 02 09 18 00 11 31 34 39 20 20 20 20 >2........149 <

…

200~209

200~209

Vacuum 작업을하면, 위에존재하는튜플들은그대로유지되고, delete 된자리 150부터 200~209가 reuse됨위의 Item Pointer는아래의 200~209 튜플을가리킴


Questions


000000 07 00 00 00 58 96 24 1a 00 00 05 00 d0 01 80 18 >....X.$.........<

…

0000e0 60 98 40 00 40 98 40 00 20 98 40 00 00 98 40 00 >`.@.@.@. .@...@.<

0000f0 e0 97 40 00 c0 97 40 00 a0 97 40 00 80 97 40 00 >..@...@...@...@.<

…

0001b0 60 99 40 00 40 99 40 00 20 99 40 00 00 99 40 00 >`.@.@.@. .@...@.<

0001c0 e0 98 40 00 c0 98 40 00 a0 98 40 00 80 98 40 00 >..@...@...@...@.<

0001d0 20 92 40 00 00 00 00 00 00 00 00 00 00 00 00 00 > .@.............<

0001e0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >................<

001220 bb 31 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >.1..............<

001230 6f 00 01 00 02 08 18 00 11 32 36 30 20 20 20 20 >o........260 <

001240 bb 31 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >.1..............<

001250 64 00 01 00 02 08 18 00 11 32 35 39 20 20 20 20 >d........259 <

…

001860 bb 31 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >.1..............<

001870 33 00 01 00 02 08 18 00 11 32 31 30 20 20 20 20 >3........210 <

001880 b9 31 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >.1..............<

001890 6e 00 01 00 02 09 18 00 11 32 30 39 20 20 20 20 >n........209 <

0018a0 b9 31 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >.1..............<

0018b0 6d 00 01 00 02 09 18 00 11 32 30 38 20 20 20 20 >m........208 <

…

0019a0 b9 31 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >.1..............<

0019b0 65 00 01 00 02 09 18 00 11 32 30 30 20 20 20 20 >e........200 <

0019c0 b7 31 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >.1..............<

0019d0 32 00 01 00 02 09 18 00 11 31 34 39 20 20 20 20 >2........149 <

…새로 Insert 된 51건

210~260

위에 남아있던 200~209는새로 Insert된 210~260으로 reuse됨


Questions

vauum full myt;

000000 07 00 00 00 58 96 24 1a 00 00 05 00 d0 01 80 18 >....X.$.........<

…

0000e0 60 98 40 00 40 98 40 00 20 98 40 00 00 98 40 00 >`.@.@.@. .@...@.<

0000f0 e0 97 40 00 c0 97 40 00 a0 97 40 00 80 97 40 00 >..@...@...@...@.<

…

0001b0 60 99 40 00 40 99 40 00 20 99 40 00 00 99 40 00 >`.@.@.@. .@...@.<

0001c0 e0 98 40 00 c0 98 40 00 a0 98 40 00 80 98 40 00 >..@...@...@...@.<

0001d0 20 92 40 00 00 00 00 00 00 00 00 00 00 00 00 00 > .@.............<

0001e0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >................<

001220 bb 31 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >.1..............<

001230 6f 00 01 00 02 0b 18 00 11 32 36 30 20 20 20 20 >o........260 <

001240 b9 31 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >.1..............<

001250 6e 00 01 00 02 0b 18 00 11 32 30 39 20 20 20 20 >n........209 <

…

001360 b9 31 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >.1..............<

001370 65 00 01 00 02 0b 18 00 11 32 30 30 20 20 20 20 >e........200 <

001380 bb 31 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >.1..............<

001390 64 00 01 00 02 0b 18 00 11 32 35 39 20 20 20 20 >d........259 <

…

0019a0 bb 31 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >.1..............<

0019b0 33 00 01 00 02 0b 18 00 11 32 31 30 20 20 20 20 >3........210 <

0019c0 b7 31 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >.1..............<

0019d0 32 00 01 00 02 0b 18 00 11 31 34 39 20 20 20 20 >2........149 <

…

100~149, 210~259, 200~209, 260 순으로튜플이 정리됨

200~209

210~259

260

100~149


02. [MySQL] Page Dump 분석

발표자: 연구컨텐츠팀 이근오


MySQL Page Dump 분석

출처: 하등성(何登成) 블로그http://hedengcheng.com/?p=118

하등성(何登成)이분석한 Page 구조 그림 (중국어)

http://hedengcheng.com/?p=118


출처: https://blog.jcole.us/2013/01/03/the-basics-of-innodb-space-file-layout/


- 기본 Page 사이즈 : 16 KB- 모든 Page는 Header(38 Byte) 와 Trailer(8 Byte) 로 구성


create table exem_i.t1 ( c1 char(04), c2 char(1), c3 char(7), c4 char(7) ) engine=innodb ;

There are 5 directory slots

beginning of free space

Slot 1:Infimum을가리킴

Slot M:Supremum을가리킴

last record inserted at location

Field Length Per Field 1 byte


위와 같은 구조로 T1 테이블을 생성하고, 12건의 데이터를Insert 한 후, T1테이블에 해당되는 덤프파일을 분석한 내용


03. [MySQL] 통계정보 관리

발표자: 연구컨텐츠팀 이대덕


MySQL 통계정보 관리

mysql> show global variables like '%stats%';+--------------------------------------+---------------+| Variable_name | Value |+--------------------------------------+---------------+| innodb_stats_auto_recalc | ON || innodb_stats_method | nulls_equal || innodb_stats_on_metadata | OFF || innodb_stats_persistent | ON || innodb_stats_persistent_sample_pages | 20 || innodb_stats_sample_pages | 8 || innodb_stats_transient_sample_pages | 8 || myisam_stats_method | nulls_unequal |+--------------------------------------+---------------+8 rows in set (0.01 sec)

innodb_stats_auto_recalc ON boolean• 테이블의로우가 10%이상변경되면 recalculate함• innodb_stats_persistent가 on 되어있어야함• stats_auto_recalc로테이블단위설정가능

innodb_stats_methodmyisam_stats_method

nulls_equal

nulls_equalnulls_unequalnulls_ignored

• Null 값처리방법(동일처리, 불일치, 무시)

innodb_stats_on_metadata OFF boolean

• SHOW TABLE STATUS 명령어사용• INFORMATION_SCHEMA.TABLES 테이블과 INFORMATI

ON_SCHEMA.STATISTICS 테이블에엑세스시통계정보갱신

innodb_stats_persistent ON boolean• 통계정보를영구적으로디스크에저장할지여부,

테이블생성시 stats_persistent옵션으로테이블별설정가능

innodb_stats_persistent_sample_pages 20 integer • 통계정보를디스크에저장할때샘플링페이지수

innodb_stats_sample_pages • 5.6 버전부터사용되지않음

innodb_stats_transient_sample_pages 8 integer • 통계정보를자동으로수집할때샘플링페이지수

show global variables like ‘%stats%’;


mysql> select * from mysql.innodb_table_stats;+---------------+---------------+---------------------+--------+----------------------+--------------------------+| database_name | table_name | last_update | n_rows | clustered_index_size | sum_of_other_index_sizes |+---------------+---------------+---------------------+--------+----------------------+--------------------------+| employees | employees | 2016-06-22 14:46:23 | 299468 | 929 | 0 || exem_i | foo | 2016-06-20 14:51:25 | 0 | 1 | 0 || exem_i | t1 | 2016-06-28 14:26:46 | 5 | 1 | 0 || mysql | gtid_executed | 2016-06-20 10:55:38 | 0 | 1 | 0 || mysqlslap | t1 | 2016-06-23 09:54:45 | 2 | 1 | 0 || sys | sys_config | 2016-06-20 10:55:39 | 6 | 1 | 0 |+---------------+---------------+---------------------+--------+----------------------+--------------------------+6 rows in set (0.00 sec)

database_name 데이터베이스이름

table_name 테이블이나파티션이름

last_update 마지막으로갱신된시간

n_rows 로우수

clustered_index_size 프라이머리인덱스사이즈(페이지)

sum_of_other_index_sizesPK인덱스를제외한모든인덱스의사이즈합계


select * from mysql.innodb_table_stats;



mysql> select * from mysql.innodb_index_stats where table_name = 'employees';+---------------+------------+------------+---------------------+--------------+------------+-------------+-----------------------------------+| database_name | table_name | index_name | last_update | stat_name | stat_value | sample_size | stat_description |+---------------+------------+------------+---------------------+--------------+------------+-------------+-----------------------------------+| employees | employees | PRIMARY | 2016-06-22 14:46:23 | n_diff_pfx01 | 299468 | 20 | emp_no || employees | employees | PRIMARY | 2016-06-22 14:46:23 | n_leaf_pages | 886 | NULL | Number of leaf pages in the index || employees | employees | PRIMARY | 2016-06-22 14:46:23 | size | 929 | NULL | Number of pages in the index |+---------------+------------+------------+---------------------+--------------+------------+-------------+-----------------------------------+3 rows in set (0.06 sec)

database_name 데이터베이스이름

table_name 테이블이나파티션이름

index_name 인덱스이름

last_update 마지막으로갱신된시간

stat_name 통계정보의이름

stat_value 해당통계정보의수치

sample_sizestat_value를측정할때의샘플링한사이즈

stat_description 해당통계정보의설명

select * from mysql.innodb_index_stats where table_name = 'employees';

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