数据库内核之数据文件学习

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Postgres数据库内核框架学习

数据文件

实例目录下的数据文件

  • base 存放数据库数据文件
[postgres@local99:~/study/test/bin/data/base/13579]$ ls
112       13430_fsm  13445_fsm  2600_fsm  2606      2611      2618_fsm  2659  2678  2693      2831      2995      3351      3456      3575      3603      3997  4157  4172  827
113       13430_vm   13445_vm   2600_vm   2606_fsm  2612      2618_vm   2660  2679  2696      2832      2996      3379      3456_fsm  3576      3603_fsm  4143  4158  4173  828
1247      13432      13447      2601      2606_vm   2612_fsm  2619      2661  2680  2699      2833      3079      3380      3456_vm   3596      3603_vm   4144  4159  4174  pg_filenode.map
1247_fsm  13434      13449      2601_fsm  2607      2612_vm   2619_fsm  2662  2681  2701      2834      3079_fsm  3381      3466      3597      3604      4145  4160  5002  PG_VERSION
1247_vm   13435      1417       2601_vm   2607_fsm  2613      2619_vm   2663  2682  2702      2835      3079_vm   3394      3467      3598      3605      4146  4161  548
1249      13435_fsm  1418       2602      2607_vm   2615      2620      2664  2683  2703      2836      3080      3394_fsm  3468      3599      3606      4147  4162  549
1249_fsm  13435_vm   174        2602_fsm  2608      2615_fsm  2650      2665  2684  2704      2837      3081      3394_vm   3501      3600      3607      4148  4163  6102
1249_vm   13437      175        2602_vm   2608_fsm  2615_vm   2651      2666  2685  2753      2838      3085      3395      3502      3600_fsm  3608      4149  4164  6104
1255      13439      2187       2603      2608_vm   2616      2652      2667  2686  2753_fsm  2838_fsm  3118      3429      3503      3600_vm   3609      4150  4165  6106
1255_fsm  13440      2224       2603_fsm  2609      2616_fsm  2653      2668  2687  2753_vm   2838_vm   3119      3430      3534      3601      3712      4151  4166  6110
1255_vm   13440_fsm  2328       2603_vm   2609_fsm  2616_vm   2654      2669  2688  2754      2839      3164      3431      3541      3601_fsm  3764      4152  4167  6111
1259      13440_vm   2336       2604      2609_vm   2617      2655      2670  2689  2755      2840      3256      3433      3541_fsm  3601_vm   3764_fsm  4153  4168  6112
1259_fsm  13442      2337       2605      2610      2617_fsm  2656      2673  2690  2756      2840_fsm  3257      3439      3541_vm   3602      3764_vm   4154  4169  6113
1259_vm   13444      2579       2605_fsm  2610_fsm  2617_vm   2657      2674  2691  2757      2840_vm   3258      3440      3542      3602_fsm  3766      4155  4170  6117
13430     13445      2600       2605_vm   2610_vm   2618      2658      2675  2692  2830      2841      3350      3455      3574      3602_vm   3767      4156  4171  826
[postgres@local99:~/study/test/bin/data/base/13579]$

表数据文件有三个,以表的oid命令,可以根据表的oid查看对应的表名

postgres=# select * from pg_class where oid= 1247;
 oid  | relname | relnamespace | reltype | reloftype | relowner | relam | relfilenode | reltablespace | relpages | reltuples | relallvisible | reltoastrelid | relhasindex | relisshared | re
lpersistence | relkind | relnatts | relchecks | relhasrules | relhastriggers | relhassubclass | relrowsecurity | relforcerowsecurity | relispopulated | relreplident | relispartition | relre
write | relfrozenxid | relminmxid |                 relacl                  | reloptions | relpartbound 
------+---------+--------------+---------+-----------+----------+-------+-------------+---------------+----------+-----------+---------------+---------------+-------------+-------------+---
-------------+---------+----------+-----------+-------------+----------------+----------------+----------------+---------------------+----------------+--------------+----------------+------
------+--------------+------------+-----------------------------------------+------------+--------------
 1247 | pg_type |           11 |      71 |         0 |       10 |     2 |           0 |             0 |       10 |       411 |            10 |          4171 | t           | f           | p 
             | r       |       31 |         0 | f           | f              | f              | f              | f                   | t              | n            | f              |      
    0 |          479 |          1 | postgres=arwdDxt/postgres,=r/postgres |            | 
(1 row)

postgres=# select * from pg_class where oid= 1249;
 oid  |   relname    | relnamespace | reltype | reloftype | relowner | relam | relfilenode | reltablespace | relpages | reltuples | relallvisible | reltoastrelid | relhasindex | relisshared
 | relpersistence | relkind | relnatts | relchecks | relhasrules | relhastriggers | relhassubclass | relrowsecurity | relforcerowsecurity | relispopulated | relreplident | relispartition | 
relrewrite | relfrozenxid | relminmxid |                 relacl                  | reloptions | relpartbound 
------+--------------+--------------+---------+-----------+----------+-------+-------------+---------------+----------+-----------+---------------+---------------+-------------+------------
-+----------------+---------+----------+-----------+-------------+----------------+----------------+----------------+---------------------+----------------+--------------+----------------+-
-----------+--------------+------------+-----------------------------------------+------------+--------------
 1249 | pg_attribute |           11 |      75 |         0 |       10 |     2 |           0 |             0 |       53 |      2861 |            53 |             0 | t           | f          
 | p              | r       |       25 |         0 | f           | f              | f              | f              | f                   | t              | n            | f              | 
         0 |          479 |          1 | postgres=arwdDxt/postgres,=r/postgres |            | 
(1 row)

postgres=# select * from pg_class where oid= 1255;
 oid  | relname | relnamespace | reltype | reloftype | relowner | relam | relfilenode | reltablespace | relpages | reltuples | relallvisible | reltoastrelid | relhasindex | relisshared | re
lpersistence | relkind | relnatts | relchecks | relhasrules | relhastriggers | relhassubclass | relrowsecurity | relforcerowsecurity | relispopulated | relreplident | relispartition | relre
write | relfrozenxid | relminmxid |                 relacl                  | reloptions | relpartbound 
------+---------+--------------+---------+-----------+----------+-------+-------------+---------------+----------+-----------+---------------+---------------+-------------+-------------+---
-------------+---------+----------+-----------+-------------+----------------+----------------+----------------+---------------------+----------------+--------------+----------------+------
------+--------------+------------+-----------------------------------------+------------+--------------
 1255 | pg_proc |           11 |      81 |         0 |       10 |     2 |           0 |             0 |       81 |      3034 |            81 |          2836 | t           | f           | p 
             | r       |       29 |         0 | f           | f              | f              | f              | f                   | t              | n            | f              |      
    0 |          479 |          1 | postgres=arwdDxt/postgres,=r/postgres |            | 
(1 row)

postgres=#

1247: oid为1247的表对应的表数据,即实际存储表数据的文件
1247_fsm: 存储空闲空间索引,用来索引1247表文件中的空闲空间,从而可以为需要插入的数据快速找到空闲的空间
1247_vm:用于标识数据库中表的可见性的文件

  • global 该目录存储全局的数据文件,如pg_database、pg_control文件等一些共享数据
[postgres@local99:~/study/test/bin/data/global]$ ls
1213      1214      1232  1260_fsm  1261_fsm  1262_fsm  2396_fsm  2671  2677  2697  2847  2966  3593  4175  4178  4183  4186  6002  6115             pg_internal.init
1213_fsm  1214_fsm  1233  1260_vm   1261_vm   1262_vm   2396_vm   2672  2694  2698  2964  2967  4060  4176  4181  4184  6000  6100  pg_control
1213_vm   1214_vm   1260  1261      1262      2396      2397      2676  2695  2846  2965  3592  4061  4177  4182  4185  6001  6114  pg_filenode.map
[postgres@local99:~/study/test/bin/data/global]$
postgres=# select * from pg_class where oid= 1213;
 oid  |    relname    | relnamespace | reltype | reloftype | relowner | relam | relfilenode | reltablespace | relpages | reltuples | relallvisible | reltoastrelid | relhasindex | relisshare
d | relpersistence | relkind | relnatts | relchecks | relhasrules | relhastriggers | relhassubclass | relrowsecurity | relforcerowsecurity | relispopulated | relreplident | relispartition |
 relrewrite | relfrozenxid | relminmxid |                 relacl                  | reloptions | relpartbound 
------+---------------+--------------+---------+-----------+----------+-------+-------------+---------------+----------+-----------+---------------+---------------+-------------+-----------
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