Question

我从终端

sudo su postgres

psql

\l：

postgres=# \l
                                  List of databases
   Name    |  Owner   | Encoding |   Collate   |    Ctype    |   Access privileges   
-----------+----------+----------+-------------+-------------+-----------------------
 nwnx      | nwnx     | UTF8     | en_US.UTF-8 | en_US.UTF-8 | 
 postgres  | postgres | UTF8     | en_US.UTF-8 | en_US.UTF-8 | 
 template0 | postgres | UTF8     | en_US.UTF-8 | en_US.UTF-8 | =c/postgres          +
           |          |          |             |             | postgres=CTc/postgres
 template1 | postgres | UTF8     | en_US.UTF-8 | en_US.UTF-8 | =c/postgres          +
           |          |          |             |             | postgres=CTc/postgres
(4 rows)

但是当尝试连接到它时：

\c nwnx：

FATAL:  database "nwnx" does not exist
Previous connection kept

quote_ident：

postgres=# select quote_ident(datname) from pg_database;
 quote_ident 
-------------
 postgres
 template1
 template0
 nwnx
(4 rows)

dumpall ：

pg_dumpall --schema-only | grep '\connect'
\connect template1
pg_dump: [archiver (db)] connection to database "nwnx" failed: FATAL:  database "nwnx" does not exist
pg_dumpall: pg_dump failed on database "nwnx", exiting

创建脚本：

pg_dumpall --schema-only | grep -i database
-- PostgreSQL database cluster dump
-- PostgreSQL database dump
-- Dumped from database version 11.5
-- PostgreSQL database dump complete
pg_dump: [archiver (db)] connection to database "nwnx" failed: FATAL:  database "nwnx" does not exist
pg_dumpall: pg_dump failed on database "nwnx", exiting

以nwnx用户身份连接

$: psql postgres -U nwnx
psql (11.5)
Type "help" for help.

postgres=> \conninfo
You are connected to database "postgres" as user "nwnx" via socket in "/run/postgresql" at port "5432".
postgres=> \l
                                  List of databases
   Name    |  Owner   | Encoding |   Collate   |    Ctype    |   Access privileges   
-----------+----------+----------+-------------+-------------+-----------------------
 nwnx      | nwnx     | UTF8     | en_US.UTF-8 | en_US.UTF-8 | 
 postgres  | postgres | UTF8     | en_US.UTF-8 | en_US.UTF-8 | 
 template0 | postgres | UTF8     | en_US.UTF-8 | en_US.UTF-8 | =c/postgres          +
           |          |          |             |             | postgres=CTc/postgres
 template1 | postgres | UTF8     | en_US.UTF-8 | en_US.UTF-8 | =c/postgres          +
           |          |          |             |             | postgres=CTc/postgres
(4 rows)

postgres=> \c nwnx
FATAL:  database "nwnx" does not exist
Previous connection kept

@ laurenz-albe提供的解决方案：

显示所有数据库

postgres=# select oid, datname, datname::bytea FROM pg_database;
  oid  |  datname  |       datname        
-------+-----------+----------------------
 13121 | postgres  | \x706f737467726573
     1 | template1 | \x74656d706c61746531
 13120 | template0 | \x74656d706c61746530
 59515 | nwnx      | \x6e776e78
(4 rows)

检查是否忽略了nwnx（必须为datname使用别名）

postgres=# SELECT oid, datname dn, datname::bytea FROM pg_database ORDER BY dn;
  oid  |    dn     |       datname        
-------+-----------+----------------------
 13121 | postgres  | \x706f737467726573
 13120 | template0 | \x74656d706c61746530
     1 | template1 | \x74656d706c61746531
(3 rows)

我按照解决方案中的说明进行操作，效果很好！非常感谢你！

Postgres版本为11.5

关于我在做什么错或正在发生什么的任何提示？

Answer 1

这看起来很像数据库损坏，尤其是索引pg_database_datname_index（在GetDatabaseTuple()中使用的索引）已损坏。

请确保尝试以下操作：

-- should show all databases
SELECT oid, datname, datname::bytea FROM pg_database;
SET enable_seqscan = off;
-- should omit database "nwnx"
SELECT oid, datname, datname::bytea FROM pg_database ORDER BY datname;

如果这证实了我的怀疑，请执行以下操作：

使用
停止数据库
```
pg_ctl stop -m immediate -D /path/to/data/directory
```
并对数据库目录进行冷备份。

使用

启动数据库

pg_ctl start -o -P -D /path/to/data/directory

连接到数据库postgres并运行
```
REINDEX TABLE pg_database;
```
停止并重新启动PostgreSQL。

现在从群集中取出一个pg_dumpall，并将其还原到使用initdb创建的新群集中。

Postgres将列出我的数据库，但是当我尝试连接到数据库时它不存在

1 个答案: