Channy's blog
//Description:
//Create Date: 2020-01-18 23:22:01
//Author: channy
007_postgres_store_struct
postgres store struct
系统表
pg_database 记录了当前数据库集所有的数据库
- 其中每个数据库有一个oid，对应base下同名文件夹，存放对应数据库的信息
postgres=# select * from pg_database
postgres-# ;
oid | datname | datdba | encoding | datcollate | datctype | datistemplate | datallowconn | datconnlimit | datlastsysoid | datfrozenxid | datminmxid | dattables
pace | datacl
-------+-----------+--------+----------+-------------+-------------+---------------+--------------+--------------+---------------+--------------+------------+----------
-----+----------------------------------------------------------
12711 | postgres | 10 | 6 | en_US.UTF-8 | en_US.UTF-8 | f | t | -1 | 12710 | 479 | 1 |
1663 | {=Tc/postgres,postgres=CTc/postgres,channy=CTc/postgres}
1 | template1 | 10 | 6 | en_US.UTF-8 | en_US.UTF-8 | t | t | -1 | 12710 | 479 | 1 |
1663 | {=c/postgres,postgres=CTc/postgres}
12710 | template0 | 10 | 6 | en_US.UTF-8 | en_US.UTF-8 | t | f | -1 | 12710 | 479 | 1 |
1663 | {=c/postgres,postgres=CTc/postgres}
(3 rows)
postgres@channy-VirtualBox:/usr/local/pgsql/data/base$ ls
1 12710 12711
- pg_class 记录了数据表对应的文件夹名称relfilenode
postgres=# select * from pg_class limit 3;
oid | relname | relnamespace | reltype | reloftype | relowner | relam | relfilenode | reltablespace | relpages | reltuples | relallvisible | reltoastrelid | relha
sindex | relisshared | relpersistence | relkind | relnatts | relchecks | relhasrules | relhastriggers | relhassubclass | relrowsecurity | relforcerowsecurity | relispop
ulated | relreplident | relispartition | relrewrite | relfrozenxid | relminmxid | relacl | reloptions | relpartbound
-------+------------+--------------+---------+-----------+----------+-------+-------------+---------------+----------+-----------+---------------+---------------+------
-------+-------------+----------------+---------+----------+-----------+-------------+----------------+----------------+----------------+---------------------+---------
-------+--------------+----------------+------------+--------------+------------+--------+------------+--------------
16392 | debugtable | 2200 | 16394 | 0 | 10 | 2 | 16392 | 0 | 0 | 0 | 0 | 0 | f
| f | p | r | 3 | 0 | f | f | f | f | f | t
| d | f | 0 | 488 | 1 | | |
16396 | seqtable | 2200 | 16397 | 0 | 10 | 0 | 16396 | 0 | 1 | 1 | 0 | 0 | f
| f | p | S | 3 | 0 | f | f | f | f | f | t
| n | f | 0 | 0 | 0 | | |
16401 | jointable | 2200 | 16403 | 0 | 10 | 2 | 16401 | 0 | 0 | 0 | 0 | 0 | f
| f | p | r | 4 | 0 | f | f | f | f | f | t
| d | f | 0 | 515 | 1 | | |
(3 rows)
postgres@channy-VirtualBox:/usr/local/pgsql/data/base/12711$ ls -lrht 16*
-rw-r-x--- 1 postgres postgres 8.0K 1月 6 17:01 16392
-rw-r----- 1 postgres postgres 8.0K 1月 7 19:00 16396
-rw-r----- 1 postgres postgres 8.0K 1月 9 12:13 16401
page、tuple
