下面的内容需要理解postgres术语 page, tuple, regclass, relname. sql command 需要用到 pgstattuple,pageinspect extension.

Setup Extension

  create extension pgstatuple
  create extension pageinspect 
  

查询page, index 详细信息

• show how many pages in one table
  select pg_relpages(regclass)

• show one table tuple information
  select * from pgstattuple(regclass)

• show one table index information
  select * from pgstatindex(regclass)

• show one page information
  select * from page_header(get_raw_page(relname text, 'main', page number))

• show one page all tuples information
  select * from heap_page_items(get_raw_page(relname text, 'main', page number))

• show one index information
  select * from bt_metap(relname text);

• show one index page information
  select * from bt_page_stats(relname text, page number)

• show one index page all tuples information
  select * from bt_page_items(relname text, page number)

• 查看database 所有的含有需要toast子段的table
  select t1.relid, t1.schemaname, t1.relname, t2.relid, t2.schemaname, t2.relname from pg_stat_all_tables t1 inner join pg_stat_all_tables t2 on 'pg_toast_'|| t1.relid = t2.relname and t1.schemaname = 'public'