PostgreSQL下安装pg_stat_statements

安装过程如下：进入安装包的contrib/pg_stat_statements目录，执行编译和安装动作：

[root@server pg_stat_statements]# pwd /soft/postgresql-9.1.2/contrib/pg_stat_statements [root@server pg_stat_statements]# make && make install make: `all' 
/bin/mkdir -p '/usr/local/pgsql/lib' /bin/mkdir -p '/usr/local/pgsql/share/extension' /bin/sh ../../config/install-sh -c -m 755  pg_stat_statements.so '/usr/local/pgsql/lib/pg_stat_statements.so' /bin/sh ../../config/install-sh -c -m 644 ./pg_stat_statements.control '/usr/local/pgsql/share/extension/' /bin/sh ../../config/install-sh -c -m 644 ./pg_stat_statements--1.0.sql ./pg_stat_statements--unpackaged--1.0.sql  '/usr/local/pgsql/share/extension/' [root@server pg_stat_statements]# 

然后，由于pg_stat_statements 既使用了hook，同时又是以 extension 形式被使用，所以需要再作两件事情：

A: 在postgresql.conf中，进行配置：

shared_preload_libraries = 'pg_stat_statements'         # (change requires restart) custom_variable_classes = 'pg_stat_statements' pg_stat_statements.max = 1000 pg_stat_statements.track = top pg_stat_statements.track_utility = true pg_stat_statements.save = true

shared_preload_libraries = 'pg_stat_statements'，表示要在启动时导入pg_stat_statements 动态库。

custom_variable_classes = 'pg_stat_statements'，是为了其下面的几个配置项。
pg_stat_statements.max = 1000，表示监控的语句最多为1000句。
pg_stat_statements.track = top，表示不监控嵌套的sql语句。
pg_stat_statements.track_utility = true，表示对 INSERT/UPDATE/DELETE/SELECT 之外的sql动作也作监控。
pg_stat_statements.save = true，表示当postgresql停止时，把信息存入磁盘文件以备下次启动时再使用。

B: 重新启动 postgresql，然后生成 extension:

[root@server ~]# su - postgres [postgres@server ~]$ pwd /home/postgres [postgres@server ~]$ cd /usr/local/pgsql [postgres@server pgsql]$ ./bin/psql -d postgres psql (9.1.2) Type "help" for help. postgres=# create extension pg_stat_statements; CREATE EXTENSION postgres=# 

简单验证：

postgres=# select count(*) from pg_stat_statements; count 
-------
2 (1 row) postgres=# \x Expanded display is on. postgres=# select * from pg_stat_statements; -[ RECORD 1 ]-------+----------------------------------------------------------- -------------------------------------------------------------------------------- -------------------------------------
userid              | 10 dbid | 12699 query | select count(*) from pg_stat_statements; calls | 1 total_time | 5.4e-05 rows | 1 shared_blks_hit | 0 shared_blks_read | 0 shared_blks_written | 0 local_blks_hit | 0 local_blks_read | 0 local_blks_written | 0 temp_blks_read | 0 temp_blks_written | 0
-[ RECORD 2 ]-------+----------------------------------------------------------- -------------------------------------------------------------------------------- -------------------------------------
userid              | 10 dbid | 12699 query | SELECT n.nspname as "Schema", |   c.relname as "Name", |   CASE c.relkind WHEN 'r' THEN 'table' WHEN 'v' THEN 'view' WHEN 'i' THEN 'index' WHEN 'S' THEN 'sequence' WHEN 's' THEN 'special' WHEN 'f' THEN 'foreign table' END as "T ype", |   pg_catalog.pg_get_userbyid(c.relowner) as "Owner" | FROM pg_catalog.pg_class c |      LEFT JOIN pg_catalog.pg_namespace n ON n.oid = c.relnamespace | WHERE c.relkind IN ('r','v','S','f','') |       AND n.nspname <> 'pg_catalog'
                    |       AND n.nspname <> 'information_schema'
                    |       AND n.nspname !~ '^pg_toast'
                    |   AND pg_catalog.pg_table_is_visible(c.oid) | ORDER BY 1,2; calls | 1 total_time | 0.00081 rows | 0 shared_blks_hit | 564 shared_blks_read | 1 shared_blks_written | 0 local_blks_hit | 0 local_blks_read | 0 local_blks_written | 0 temp_blks_read | 0 temp_blks_written | 0
-[ RECORD 3 ]-------+--------------------------------------------------------------------------------------------------------------------------------------------------------------------------- -----
userid              | 10 dbid | 12699 query | create extension pg_stat_statements; calls | 1 total_time | 0.199004 rows | 0 shared_blks_hit | 489 shared_blks_read | 105 shared_blks_written | 0 local_blks_hit | 0 local_blks_read | 0 local_blks_written | 0 temp_blks_read | 0 temp_blks_written | 0 postgres=#