客户误操作将系统表pg_authid表删除，过后自己恢复了所有的User，但是OID是系统生成的已经与原来的不一样，需要修复

处理方式

由于系统表中OID全部都是原User OID与新User OID对不上，如果将系统表对应的OID全部更新为新的User OID工作量比较大，所以选择根据原User OID 重建pg_authid表

具体步骤

找出原User OID对应关系

由于系统目前状况psql中使用\l 或者\d 我们看到的Owner都会是Unknow状态，并且会显示出原User的OID，让客户配合梳理出这些对象对应的用户则可以得出原User OID对应关系:

• 原User OID对应关系

16384     | mintq
24824936  | xiangqd
3373      | pg_monitor
3374      | pg_read_all_settings
3375      | pg_read_all_stats
3377      | pg_stat_scan_tables
4200      | pg_signal_backend
10        | postgres

• 新User OID对应关系

postgres=# select oid , rolname from pg_authid;
   oid    |       rolname
----------+----------------------
 54036442 | pg_monitor
 54036443 | pg_read_all_settings
 54036444 | pg_read_all_stats
 54036445 | pg_stat_scan_tables
 54036446 | pg_signal_backend
 54036447 | mintq
 54036448 | rep
 54036449 | xiangqd
 54036441 | postgres

创建一张中间表(my_authid)

• 首先查看pg_authid表相关信息

postgres=# SELECT pg_relation_filepath('pg_authid');
 pg_relation_filepath
----------------------
 global/1260
(1 row)

postgres=# \d pg_authid
                        Table "pg_catalog.pg_authid"
     Column     |           Type           | Collation | Nullable | Default
----------------+--------------------------+-----------+----------+---------
 rolname        | name                     |           | not null |
 rolsuper       | boolean                  |           | not null |
 rolinherit     | boolean                  |           | not null |
 rolcreaterole  | boolean                  |           | not null |
 rolcreatedb    | boolean                  |           | not null |
 rolcanlogin    | boolean                  |           | not null |
 rolreplication | boolean                  |           | not null |
 rolbypassrls   | boolean                  |           | not null |
 rolconnlimit   | integer                  |           | not null |
 rolpassword    | text                     |           |          |
 rolvaliduntil  | timestamp with time zone |           |          |
Indexes:
    "pg_authid_oid_index" UNIQUE, btree (oid), tablespace "pg_global"
    "pg_authid_rolname_index" UNIQUE, btree (rolname), tablespace "pg_global"
Tablespace: "pg_global"


postgres=# SELECT pg_relation_filepath('pg_authid_oid_index');
 pg_relation_filepath
----------------------
 global/2677
(1 row)

postgres=# SELECT pg_relation_filepath('pg_authid_rolname_index');
 pg_relation_filepath
----------------------
 global/2676
(1 row)


postgres=# \d+ pg_authid_oid_index
Index "pg_catalog.pg_authid_oid_index"
 Column | Type | Definition | Storage
--------+------+------------+---------
 oid    | oid  | oid        | plain
unique, btree, for table "pg_catalog.pg_authid"
Tablespace: "pg_global"

postgres=# \d+ pg_authid_rolname_index
Index "pg_catalog.pg_authid_rolname_index"
 Column  |  Type   | Definition | Storage
---------+---------+------------+---------
 rolname | cstring | rolname    | plain
unique, btree, for table "pg_catalog.pg_authid"
Tablespace: "pg_global"

• 将表中数据导出并创建my_authid表

copy pg_authid to '/pgsql/data/backup/pg_authid.txt' with (oids);

create table my_authid(like pg_authid) with oids;

create unique index my_authid_oid_index on my_authid(oid);
create unique index my_authid_rolname_index on my_authid(rolname);

• 导数数据到my_authid表中
  导入之前我们要编辑pg_authid.txt文件将对应的OID修改为原User OID对应的关系，这里postgres用户我们新添加一行 (原User OID 也就是10)，并将文件中原postgres用户名改为postgres2

copy my_authid from '/pgsql/data/backup/pg_authid.txt' with (oids);
VACUUM FULL FREEZE VERBOSE my_authid;
vacuum my_authid;

• 查看my_authid相关信息

SELECT pg_relation_filepath('my_authid'), pg_relation_filepath('my_authid_oid_index'), pg_relation_filepath('my_authid_rolname_index');

postgres=# SELECT pg_relation_filepath('my_authid'), pg_relation_filepath('my_authid_oid_index'), pg_relation_filepath('my_authid_rolname_index');
 pg_relation_filepath | pg_relation_filepath | pg_relation_filepath
----------------------+----------------------+----------------------
 base/13806/54036458  | base/13806/54036464  | base/13806/54036465
(1 row)

关闭数据库替换pg_authid表对应的物理文件

• 关闭数据
• 替换pg_authid表对应的物理文件

//整理出pg_authid表及索引与my_authid表物理文件对应管理
global/1260  => base/13806/54036458 
global/2677  => base/13806/54036464
global/2676  => base/13806/54036465

//备份原pg_authid表及索引文件
mkdir backup
cp global/1260* ./backup/.
cp global/2677* ./backup/.
cp global/2676* ./backup/.

//将my_authid表物理文件及索引拷贝覆盖原pg_authid对应的文件及索引
cp base/13806/54036458 global/1260
cp base/13806/54036458_fsm global/1260_fsm
cp base/13806/54036458_vm global/1260_vm

cp base/13806/54036464 global/2677
cp base/13806/54036465 global/2676 

• 检查观察文件时间及对比文件内容是否发生变化

ls -l global/1260*
ls -l backup/1260*
ls -l global/2677*
ls -l backup/2677*
ls -l global/2676*
ls -l backup/2676*

cmp global/1260 backup/1260
cmp global/2677 backup/2677
cmp global/2676 backup/2676

• 删除系统表cache文件

find . -name "pg_internal.init*"
find . -name "pg_internal.init*" |xargs rm

####启动数据库
启动数据库查看数据库及表的owner是否正常，不在是Unknow状态