中国用户大会 PostgreSQL WAL日志解析与应用 王硕 山东瀚高基础软件股份有限公司 2016Postgres中国用户大会 Postgres Conference China 2016 中国用户大会 CONTENTS Part 01 Part 02 Part 03 WAL 日志简介 WAL 日志工作原理 利用 WAL 日志我们可以做什么？ 2016Postgres中国用户大会 Postgres Conference China 2016 中国用户大会 Part 01 WAL 日志简介 2016Postgres中国用户大会 Postgres Conference China 2016 中国用户大会  Write Ahead Log Files • WAL 日志一般存储在$PGDATA/pg_xlog内，他们一般以类似于 00000001 LogId LogSeg • WAL 日志文件XLOG 文件是一个逻辑概念，每一个XLOG文件， 大小为4G(16*256) ，由256个segment组成； • Segment由2048个Block组成，其大小为16M ； • Block为WAL日志的最小单位， 其大小8k，由PageHeaderData 、 XlogRecord、 XLogRecData组成。

Connections with SSH Tunnels ............................................ 534 18.11. Registering Event Log on Windows .......................................................... 535 19. Server Configuration Consumption ............................................................................. 546 19.5. Write Ahead Log ..................................................................................... 553 19 Reindexing .................................................................................. 657 24.3. Log File Maintenance ............................................................................... 658

TCP/IP Connections with SSH Tunnels ...................................... 508 18.11. Registering Event Log on Windows ..................................................... 509 19. Server Configuration .... Consumption ........................................................................ 519 19.5. Write Ahead Log ............................................................................... 526 19.6. Replication Reindexing ............................................................................ 626 24.3. Log File Maintenance ......................................................................... 626 25.

Connections with SSH Tunnels ............................................ 652 18.12. Registering Event Log on Windows .......................................................... 653 19. Server Configuration Consumption ............................................................................. 667 19.5. Write Ahead Log ..................................................................................... 676 19 Reindexing .................................................................................. 821 24.3. Log File Maintenance ............................................................................... 821

TCP/IP Connections with SSH Tunnels ...................................... 617 18.12. Registering Event Log on Windows ..................................................... 618 19. Server Configuration .... Consumption ........................................................................ 631 19.5. Write Ahead Log ............................................................................... 640 19.6. Replication Reindexing ............................................................................ 777 24.3. Log File Maintenance ......................................................................... 778 25.

Connections with SSH Tunnels ............................................ 605 19.12. Registering Event Log on Windows .......................................................... 606 20. Server Configuration Consumption ............................................................................. 620 20.5. Write Ahead Log ..................................................................................... 629 20 Reindexing .................................................................................. 756 25.3. Log File Maintenance ............................................................................... 757

TCP/IP Connections with SSH Tunnels ...................................... 575 19.12. Registering Event Log on Windows ..................................................... 576 20. Server Configuration .... Consumption ........................................................................ 590 20.5. Write Ahead Log ............................................................................... 598 20.6. Replication Reindexing ............................................................................ 721 25.3. Log File Maintenance ......................................................................... 721 26.

Connections with SSH Tunnels ............................................ 590 18.12. Registering Event Log on Windows .......................................................... 591 19. Server Configuration Consumption ............................................................................. 604 19.5. Write Ahead Log ..................................................................................... 613 19 Reindexing .................................................................................. 734 24.3. Log File Maintenance ............................................................................... 735

TCP/IP Connections with SSH Tunnels ...................................... 558 18.12. Registering Event Log on Windows ..................................................... 559 19. Server Configuration .... Consumption ........................................................................ 571 19.5. Write Ahead Log ............................................................................... 579 19.6. Replication Reindexing ............................................................................ 696 24.3. Log File Maintenance ......................................................................... 696 25.

Connections with SSH Tunnels ............................................ 632 19.12. Registering Event Log on Windows .......................................................... 633 20. Server Configuration Consumption ............................................................................. 646 20.5. Write Ahead Log ..................................................................................... 655 20 Reindexing .................................................................................. 796 25.3. Log File Maintenance ............................................................................... 796