Postgres 将列出我的数据库，但当我尝试连接到它时它不存在

Question

从终端，我

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)

但是在尝试连接时：

\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 的工作解决方案：

正在显示所有数据库

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)

检查是否省略了 nwnx（必须为数据名使用别名）

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，效果非常好！非常感谢！

Postgres 版本为 11.5

关于我做错了什么或发生了什么的任何提示？

Answer 1

这看起来很像数据库损坏，特别是索引 pg_database_datname_index（在 GetDatabaseTuple() 中使用）被损坏。

为了确定，请尝试以下操作：

-- 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：

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。

用

启动数据库

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

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

现在从集群中取出一个 pg_dumpall 并将其恢复到您使用 initdb 创建的新集群。

Postgres 将列出我的数据库，但当我尝试连接到它时它不存在

Postgres will list my database, but it doesn't exist when I try connecting to it

postgresql

corruption

postgresql-11