接前文 初步学习pg_control文件之六 看 pg_control_version
以PostgreSQL9.1.1为了，其HISTORY文件中有如下的内容：
Release 9.1.2 Release Date: 2011-12-05 This release contains a variety of fixes from 9.1.1. For information about new features in the 9.1 major release, see the Section called Release 9.1.
早就写死了:
static void WriteControlFile(void) { ... /* * Initialize version and compatibility-check fields */ ControlFile->pg_control_version = PG_CONTROL_VERSION; ... }
pg_control.h中有：
/* Version identifier for this pg_control format */ #define PG_CONTROL_VERSION 903
WriteControlFile被 BootStrapXLOG 所调用(仅仅是安装的时候调用一次)
本文转自健哥的数据花园博客园博客，原文链接：http://www.cnblogs.com/gaojian/p/3228235.html，如需转载请自行联系原作者
