标签归档:PostgreSQL恢复

PostgreSQL恢复工具—pdu工具介绍

张晨同学开发了一个PostgreSQL数据恢复工具PDU(PDU: Postgresql Data Rescue Tool),我这边配合做一些测试
使用帮助命令

PDU.public=# ;

PDU数据拯救工具 | 命令帮助
━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
**基础操作**
b;                                      │ 初始化数据库元信息
exit;                                   │ 退出工具

**数据库切换**
use <db>;                               │ 指定目标数据库 (例: use logs;)
set <schema>;                           │ 指定操作模式 (例: set recovery;)

**元数据展示**
\l;                                     │ 列出所有数据库
\dn;                                    │ 显示当前数据库模式
\dt;                                    │ 列出当前模式下的表
\d+ <table>;                            │ 查看表结构详情 (例: \d+ users;)
\d <table>;                             │ 查看表列类型 (例: \d users;)

**数据导出**
unload <table>;                         │ 导出表数据 → ./<表名>.csv (例: unload orders;)
unload SCH;                             │ 导出当前模式所有数据
unload DDL;                             │ 生成模式结构定义文件
unload COPY;                            │ 生成PSQL COPY语句脚本

**误删数据恢复**
scan t1;                                │ 扫描被误删的表
restore del <Tx Number>;                │ 通过事务号恢复被误删的数据
--------------------------------------------------------------------------------------
scan drop;                              │ 扫描wal日志中的drop事务
restore drop <Tx Number>;               │ 通过事务号恢复被drop的表
add <oid> <tablename> <attibutes>;      │ 将表信息手动添加到restore库中
例如: <add 12345 t1 varchar,varchar,timestamp,varchar,numeric,varchar,varchar,varchar,numeric;>

━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
语法规则
◈ 指令后缀必须带 `;`

加载PostgreSQL元数据

PDU.public=# b;
开始初始化...
 -pg_database:</var/lib/pgsql/12/data/global/1262>
    【postgres】
      -pg_schema:</var/lib/pgsql/12/data/base/14399/2615>
      -pg_class:</var/lib/pgsql/12/data/base/14399/1259>,共55行
      -pg_attribute:</var/lib/pgsql/12/data/base/14399/1249>,共2913行
      模式:
        -->public,2张表
    【his5_dms】
      -pg_schema:</var/lib/pgsql/12/data/base/16386/2615>
      -pg_class:</var/lib/pgsql/12/data/base/16386/1259>,共793行
      -pg_attribute:</var/lib/pgsql/12/data/base/16386/1249>,共31329行
      模式:
        -->public,660张表
        -->hiscrm,55张表
        -->pgagent,8张表
        -->report,7张表
        -->statistics,10张表

查看当前有哪些库

PDU.public=# \l;
|------------------|
|     数据库名     |
|------------------|
|    postgres      |
|    template1     |
|    template0     |
|    his5_dms      |
|    restore       |
|------------------|

      5 rows selected

进入某个库

PDU.public=# use his5_dms;
|----------------------------------------|
|          模式             |  表数量    |
|----------------------------------------|
|    public                 |  660       |
|    hiscrm                 |  55        |
|    pgagent                |  8         |
|    report                 |  7         |
|    statistics             |  10        |
|----------------------------------------|

进入某个模式

his5_dms.public=# set hiscrm;
|--------------------------------------------------|
|               表名                  |  表大小    |
|--------------------------------------------------|
|    t_patient_other                  |  600.00 KB |
|    t_sys_oper_log                   |  88.00 KB  |
|    t_auth                           |  88.00 KB  |
|    t_setting_user                   |  56.00 KB  |
|    t_field_define                   |  32.00 KB  |
|    t_oper_log                       |  16.00 KB  |
|    t_role                           |  16.00 KB  |
|    t_sys_login_log                  |  8.00 KB   |
|    t_appointment_item               |  8.00 KB   |
|    t_clinic                         |  8.00 KB   |
|    t_dept                           |  8.00 KB   |
|    t_employee                       |  8.00 KB   |
|    t_menu                           |  8.00 KB   |
|    t_patient_label                  |  8.00 KB   |
|    t_patient_label_detail_tpl       |  8.00 KB   |
|    t_patient_source_ref             |  8.00 KB   |
|    t_return_visit_tpl               |  8.00 KB   |
|    t_setting_clinic                 |  8.00 KB   |
|    t_setting_notify                 |  8.00 KB   |
|    t_sms_template_category          |  8.00 KB   |
|--------------------------------------------------|

        仅显示表大小排名前 50 的表名

显示部分表

his5_dms.hiscrm=# \dt;
|--------------------------------------------------|
|               表名                  |  表大小    |
|--------------------------------------------------|
|    t_patient_other                  |  600.00 KB |
|    t_sys_oper_log                   |  88.00 KB  |
|    t_auth                           |  88.00 KB  |
|    t_setting_user                   |  56.00 KB  |
|    t_field_define                   |  32.00 KB  |
|    t_oper_log                       |  16.00 KB  |
|    t_role                           |  16.00 KB  |
|    t_sys_login_log                  |  8.00 KB   |
|    t_appointment_item               |  8.00 KB   |
|    t_clinic                         |  8.00 KB   |
|    t_dept                           |  8.00 KB   |
|    t_employee                       |  8.00 KB   |
|    t_menu                           |  8.00 KB   |
|    t_patient_label                  |  8.00 KB   |
|    t_patient_label_detail_tpl       |  8.00 KB   |
|    t_patient_source_ref             |  8.00 KB   |
|    t_return_visit_tpl               |  8.00 KB   |
|    t_setting_clinic                 |  8.00 KB   |
|    t_setting_notify                 |  8.00 KB   |
|    t_sms_template_category          |  8.00 KB   |
|--------------------------------------------------|

        仅显示表大小排名前 50 的表名

显示某个表的信息

his5_dms.hiscrm=# \d+ t_auth;
----------------------------------------------------------------
|                            建表语句                           |
----------------------------------------------------------------
   CREATE TABLE t_auth (
        id                       bigint,
        clinic_id                bigint,
        group_id                 bigint,
        parient_id               varchar(64),
        menu_id                  varchar(64),
        auth_key                 varchar(60),
        auth_name                varchar(64),
        uris                     varchar,
        rely                     varchar(255),
        state                    bigint,
        sort                     bigint,
        tag                      bigint,
        explain                  varchar(255),
        desc                     varchar(255)
   );
----------------------------------------------------------------
|                                                              |
----------------------------------------------------------------
his5_dms.hiscrm=# \d t_auth;
----------------------------------------------------------------
|                            列类型                             |
----------------------------------------------------------------
bigint,bigint,bigint,varchar,varchar,varchar,varchar,varchar,varchar,bigint,bigint,bigint,varchar,varchar

恢复表数据

his5_dms.hiscrm=# unload t_auth;
正在解析表 <t_auth>. 已解析数据页: 11, 已解析数据: 492 条
<t_auth>-</var/lib/pgsql/12/data/base/16386/16895> 解析完成, 12 个数据页 ,共计 492 条数据. 成功 492 条; 失败【0】条 
 COPY文件路径为:<his5_dms/hiscrm/t_auth.csv>

确认恢复表的数据情况

[root@xifenfeidg hiscrm]# wc -l t_auth.csv
492 t_auth.csv

QQ20250228-224837


PostgreSQL中查询表实际数据情况

his5_dms=# select count(1) from hiscrm.t_auth;
 count 
-------
   492
(1 row)
is5_dms=# \d hiscrm.t_auth;
                                Table "hiscrm.t_auth"
   Column   |          Type          | Collation | Nullable |         Default         
------------+------------------------+-----------+----------+-------------------------
 id         | bigint                 |           | not null | 
 clinic_id  | bigint                 |           |          | 
 group_id   | bigint                 |           |          | 
 parient_id | character varying(64)  |           | not null | 
 menu_id    | character varying(64)  |           | not null | 
 auth_key   | character varying(60)  |           | not null | 
 auth_name  | character varying(64)  |           | not null | 
 uris       | text                   |           | not null | 
 rely       | character varying(255) |           |          | NULL::character varying
 state      | bigint                 |           | not null | 
 sort       | bigint                 |           | not null | 
 tag        | bigint                 |           |          | '0'::bigint
 explain    | character varying(255) |           |          | NULL::character varying
 desc       | character varying(255) |           |          | NULL::character varying

truncate表

his5_dms=# truncate table hiscrm.t_auth;
TRUNCATE TABLE
his5_dms=# select count(1) from hiscrm.t_auth;
 count 
-------
     0
(1 row)

导入数据,并验证恢复效果

his5_dms=# \i /tmp/pdu/his5_dms/COPY/hiscrm_copy.sql 
SET
COPY 492
his5_dms=# select count(1) from  hiscrm.t_auth;
 count 
-------
   492
(1 row)

通过验证pdu可以在数据库离线的情况下,恢复PostgreSQL数据库中表的数据,更加方便和灵活的实现替代pg_filedump功能,而且pdu还在不断完善和新功能更新中

发表在 pdu工具 | 标签为 , , , , | 评论关闭

PostgreSQL恢复系列:pg_filedump恢复字典构造

pg_filedump是在pg数据库极端情况下直接解析数据库文件的利器,但是由于是开源软件,本身难以实现批量处理,通过对底层基表分析,可以实现批量处理功能
分析PostgreSQL库中数据库信息

--数据库查询结果
postgres=# select oid,datname,datdba,dattablespace from pg_database;
  oid  |   datname   | datdba | dattablespace 
-------+-------------+--------+---------------
 14187 | postgres    |     10 |          1663
 16403 | db_xff      |     10 |          1663
     1 | template1   |     10 |          1663
 14186 | template0   |     10 |          1663
 16407 | db_xifenfei |  16405 |         16406
(5 rows)

--通过dump 该文件解析数据
<Data> -----
 Item   1 -- Length:    0  Offset:    5 (0x0005)  Flags: REDIRECT
 Item   2 -- Length:    0  Offset:    6 (0x0006)  Flags: REDIRECT
 Item   3 -- Length:  260  Offset: 7320 (0x1c98)  Flags: NORMAL
COPY: 14187     postgres
 Item   4 -- Length:  260  Offset: 7056 (0x1b90)  Flags: NORMAL
COPY: 16403     db_xff
 Item   5 -- Length:  297  Offset: 7888 (0x1ed0)  Flags: NORMAL
COPY: 1 template1
 Item   6 -- Length:  297  Offset: 7584 (0x1da0)  Flags: NORMAL
COPY: 14186     template0
 Item   7 -- Length:  260  Offset: 6792 (0x1a88)  Flags: NORMAL
COPY: 16407     db_xifenfei

分析PostgreSQL 表空间信息

--sql查询表空间信息
postgres=# select * from pg_tablespace;
  oid  |   spcname    | spcowner | spcacl | spcoptions 
-------+--------------+----------+--------+------------
  1663 | pg_default   |       10 |        | 
  1664 | pg_global    |       10 |        | 
 16406 | tbs_xifenfei |    16405 |        | 
(3 rows)


--通过dump 该文件解析数据
<Data> -----
 Item   1 -- Length:   96  Offset: 8096 (0x1fa0)  Flags: NORMAL
COPY: 1663      pg_default
 Item   2 -- Length:   96  Offset: 8000 (0x1f40)  Flags: NORMAL
COPY: 1664      pg_global
 Item   3 -- Length:   96  Offset: 7904 (0x1ee0)  Flags: NORMAL
COPY: 16406     tbs_xifenfei

分析PostgreSQL 对象id、name、path对应关系

--对象信息查询
postgres=# select oid ,relname,relnamespace,reltype,reloftype,relowner,relam,relfilenode,
           reltablespace from pg_class where relname like 't_t%' or relname like 't_x%';
  oid  |  relname   | relnamespace | reltype | reloftype | relowner | relam | relfilenode | reltablespace 
-------+------------+--------------+---------+-----------+----------+-------+-------------+---------------
 16387 | t_xifenfei |         2200 |   16389 |         0 |       10 |     2 |       16390 |             0
 16391 | t_xff      |         2200 |   16393 |         0 |       10 |     2 |       16391 |             0
 16394 | t_xff2     |         2200 |   16396 |         0 |       10 |     2 |       16394 |             0
 16397 | t_xff3     |         2200 |   16399 |         0 |       10 |     2 |       16397 |             0
 16400 | t_xff4     |         2200 |   16402 |         0 |       10 |     2 |       16400 |             0
 16408 | t_tbs      |         2200 |   16410 |         0 |       10 |     2 |       16408 |         16406
(6 rows)

--通过dump 该文件解析数据(显示部分)
COPY: 16394     t_xff2  2200    16396   0       10      2       16394   0       0       0.000000000000  0       0       f       f       p       r
 Item  29 -- Length:    0  Offset:   31 (0x001f)  Flags: REDIRECT
 Item  30 -- Length:  172  Offset: 2592 (0x0a20)  Flags: NORMAL
COPY: 16397     t_xff3  2200    16399   0       10      2       16397   0       0       0.000000000000  0       0       f       f       p       r
 Item  31 -- Length:  205  Offset: 3376 (0x0d30)  Flags: NORMAL
COPY: 12093     pg_shadow       11      12094   0       10      0       0       0       0       0.000000000000  0       0       f       f       p       v
 Item  32 -- Length:  172  Offset: 2416 (0x0970)  Flags: NORMAL
COPY: 16400     t_xff4  2200    16402   0       10      2       16400   0       0       0.000000000000  0       0       f       f       p       r

这个里面获取到pg_class.reltablespace是表空间的id值,根据自定义表空间的规则:在pgdata/pg_tblspc创建link指向创建表空间时候的文件夹路径

-bash-4.2$ pwd
/var/lib/pgsql/12/data/pg_tblspc
-bash-4.2$ ls -ltr
total 0
lrwxrwxrwx 1 postgres postgres 30 Apr 15 20:13 16406 -> /var/lib/pgsql/12/data/tbs_xff

结合上述的pg_database,pg_tablespace,pg_class信息,可以获取到每个表对应实际的存储路径
分析PostgreSQL 模式信息

--sql查询模式信息
postgres=# select * from pg_namespace;
  oid  |      nspname       | nspowner |               nspacl                
-------+--------------------+----------+-------------------------------------
    99 | pg_toast           |       10 | 
 12314 | pg_temp_1          |       10 | 
 12315 | pg_toast_temp_1    |       10 | 
    11 | pg_catalog         |       10 | {postgres=UC/postgres,=U/postgres}
  2200 | public             |       10 | {postgres=UC/postgres,=UC/postgres}
 13887 | information_schema |       10 | {postgres=UC/postgres,=U/postgres}
 16404 | u_xifenfei         |       10 | 
(7 rows)


--通过dump 该文件解析数据
<Data> -----
 Item   1 -- Length:    0  Offset:    6 (0x0006)  Flags: REDIRECT
 Item   2 -- Length:   96  Offset: 8096 (0x1fa0)  Flags: NORMAL
COPY: 99        pg_toast
 Item   3 -- Length:    0  Offset:    7 (0x0007)  Flags: REDIRECT
 Item   4 -- Length:   96  Offset: 8000 (0x1f40)  Flags: NORMAL
COPY: 12314     pg_temp_1
 Item   5 -- Length:   96  Offset: 7904 (0x1ee0)  Flags: NORMAL
COPY: 12315     pg_toast_temp_1
 Item   6 -- Length:  141  Offset: 7760 (0x1e50)  Flags: NORMAL
COPY: 11        pg_catalog
 Item   7 -- Length:  141  Offset: 7616 (0x1dc0)  Flags: NORMAL
COPY: 2200      public
 Item   8 -- Length:    0  Offset:    9 (0x0009)  Flags: REDIRECT
 Item   9 -- Length:  141  Offset: 7472 (0x1d30)  Flags: NORMAL
COPY: 13887     information_schema
 Item  10 -- Length:   96  Offset: 7376 (0x1cd0)  Flags: NORMAL
COPY: 16404     u_xifenfei

通过pg_namespace,pg_class信息,可以获取到对象所属的模式关系,基于上述汇总,可以获取到某个模式下面,所有表id和实际存储路径,现在使用pg_filedump进行恢复,还缺少表的列类型信息,通过pg_type和pg_attribute来获取。

获取PostgreSQL表的列名称和类型[编号]信息

--sql查询列信息
postgres=# \d t_tbs
               Table "public.t_tbs"
  Column  | Type | Collation | Nullable | Default 
----------+------+-----------+----------+---------
 oid      | oid  |           |          | 
 spcname  | name |           |          | 
 spcowner | oid  |           |          | 
Tablespace: "tbs_xifenfei"

postgres=# select attrelid,attname,atttypid,attstattarget,attlen,attnum from pg_attribute where attrelid=16408;
 attrelid | attname  | atttypid | attstattarget | attlen | attnum 
----------+----------+----------+---------------+--------+--------
    16408 | tableoid |       26 |             0 |      4 |     -6
    16408 | cmax     |       29 |             0 |      4 |     -5
    16408 | xmax     |       28 |             0 |      4 |     -4
    16408 | cmin     |       29 |             0 |      4 |     -3
    16408 | xmin     |       28 |             0 |      4 |     -2
    16408 | ctid     |       27 |             0 |      6 |     -1
    16408 | oid      |       26 |            -1 |      4 |      1
    16408 | spcname  |       19 |            -1 |     64 |      2
    16408 | spcowner |       26 |            -1 |      4 |      3
(9 rows)

--dump 内容(截取部分)
 Item  11 -- Length:  144  Offset: 1424 (0x0590)  Flags: NORMAL
COPY: 16408     oid     26      -1      4       1
 Item  12 -- Length:  144  Offset: 1280 (0x0500)  Flags: NORMAL
COPY: 16408     spcname 19      -1      64      2
 Item  13 -- Length:  144  Offset: 1136 (0x0470)  Flags: NORMAL
COPY: 16408     spcowner        26      -1      4       3
 Item  14 -- Length:  144  Offset:  992 (0x03e0)  Flags: NORMAL
COPY: 16408     ctid    27      0       6       -1
 Item  15 -- Length:  144  Offset:  848 (0x0350)  Flags: NORMAL
COPY: 16408     xmin    28      0       4       -2
 Item  16 -- Length:  144  Offset:  704 (0x02c0)  Flags: NORMAL
COPY: 16408     cmin    29      0       4       -3
 Item  17 -- Length:  144  Offset:  560 (0x0230)  Flags: NORMAL
COPY: 16408     xmax    28      0       4       -4
 Item  18 -- Length:  144  Offset:  416 (0x01a0)  Flags: NORMAL
COPY: 16408     cmax    29      0       4       -5

PostgreSQL获取类型编号和实际类型名称对应关系

--查询类型编号和实际类型关系
postgres=# select oid,typname from pg_type;
  oid  |                typname                
-------+---------------------------------------
    16 | bool
    17 | bytea
    18 | char
    19 | name
    20 | int8
    21 | int2
    22 | int2vector
    23 | int4
    24 | regproc
    25 | text
    26 | oid
    27 | tid
    28 | xid
    29 | cid
……

--dump 内容(截取部分)
 Item   1 -- Length:  176  Offset: 8016 (0x1f50)  Flags: NORMAL
COPY: 16        bool
 Item   2 -- Length:  176  Offset: 7840 (0x1ea0)  Flags: NORMAL
COPY: 17        bytea
 Item   3 -- Length:  176  Offset: 7664 (0x1df0)  Flags: NORMAL
COPY: 18        char
 Item   4 -- Length:  176  Offset: 7488 (0x1d40)  Flags: NORMAL
COPY: 19        name
 Item   5 -- Length:  176  Offset: 7312 (0x1c90)  Flags: NORMAL
COPY: 20        int8
 Item   6 -- Length:  176  Offset: 7136 (0x1be0)  Flags: NORMAL
COPY: 21        int2
 Item   7 -- Length:  176  Offset: 6960 (0x1b30)  Flags: NORMAL
COPY: 22        int2vector
 Item   8 -- Length:  176  Offset: 6784 (0x1a80)  Flags: NORMAL
COPY: 23        int4
 Item   9 -- Length:  176  Offset: 6608 (0x19d0)  Flags: NORMAL
COPY: 24        regproc
 Item  10 -- Length:  176  Offset: 6432 (0x1920)  Flags: NORMAL
COPY: 25        text
 Item  11 -- Length:  176  Offset: 6256 (0x1870)  Flags: NORMAL
COPY: 26        oid
 Item  12 -- Length:  176  Offset: 6080 (0x17c0)  Flags: NORMAL
COPY: 27        tid
 Item  13 -- Length:  176  Offset: 5904 (0x1710)  Flags: NORMAL
COPY: 28        xid
 Item  14 -- Length:  176  Offset: 5728 (0x1660)  Flags: NORMAL
COPY: 29        cid
 Item  15 -- Length:  176  Offset: 5552 (0x15b0)  Flags: NORMAL
COPY: 30        oidvector

通过pg_class、pg_type和pg_attribute可以获取对象的表的列名称,数据类型等信息。通过以上几个对象,即可获取到pg_filedmp处理所需要的所有信息,然后可以实现批量处理

发表在 PostgreSQL恢复 | 标签为 , , | 评论关闭