Psql meta-command conninfo+

Maiquel Grassi <grassi@hotmail.com.br>

From: Maiquel Grassi <grassi@hotmail.com.br>
To: "pgsql-hackers@postgresql.org" <pgsql-hackers@postgresql.org>
Date: 2024-02-06T17:27:01Z
Lists: pgsql-hackers

Attachments

Hi,


I'm seeking to improve the \conninfo meta-command in psql. Currently, it provides limited information about the current connection. I believe that expanding it using the concept of "plus" [+] could ease the work of DBAs, SysAdmins, DevOps, etc., who manage a large volume of databases and/or multiple PostgreSQL servers. The objective of this enhancement is to obtain quick information about the current connection (session). I believe that for a PostgreSQL administrator, it is not feasible to write a plpgsql function and apply it to all databases (for example, imagine managing over 200 databases). I have an example on GitHub https://github.com/maiquelgrassi/DBA-toolkit/blob/main/cluster/dba_whoami_function.sql of a plpgsql function demonstrating exactly what I believe is impractical for the daily routine of a PostgreSQL professional. I see psql's meta-commands as significant allies in daily work in productive environments.


Note: As this is a prototype, I will adjust the rest (documentation, tests, etc.) once an agreement is reached.

Use cases for both the current and improved command bellow.

Connection 1 ("remote server"):

[postgres@localhost bin]$ ./psql -h 192.168.0.5 -p 5433 -U postgres -d postgres

psql (17devel, server 16.1)
Type "help" for help.

postgres=# \conninfo
You are connected to database "postgres" as user "postgres" on host "192.168.0.5" at port "5433".
postgres=# \conninfo+
 Current Connection Information
   Attribute    |     Value
----------------+----------------
 Database       | postgres
 User           | postgres
 Server Version | 16.1
 Server Address | 192.168.0.5/32
 Server Port    | 5433
 Client Address | 192.168.0.5/32
 Client Port    | 52716
 Session PID    | 21624
(8 rows)


Connection 2 (socket):

[postgres@localhost bin]$ ./psql

psql (17devel)
Type "help" for help.

postgres=# \conninfo
You are connected to database "postgres" as user "postgres" via socket in "/tmp" at port "5432".
postgres=# \conninfo+
      Current Connection Information
    Attribute     |         Value
------------------+-----------------------
 Info             | Connected via socket!
 Database         | postgres
 User             | postgres
 Socket Directory | /tmp
 Server Version   | 17devel
 Server Port      | 5432
 Session PID      | 27586
(7 rows)

Connection 3 (localhost):
[postgres@localhost bin]$ ./psql -h localhost
psql (17devel)
Type "help" for help.

postgres=# \conninfo
You are connected to database "postgres" as user "postgres" on host "localhost" (address "::1") at port "5432".
postgres=# \conninfo+
Current Connection Information
   Attribute    |   Value
----------------+-----------
 Database       | postgres
 User           | postgres
 Host           | localhost
 Server Version | 17devel
 Server Address | ::1/128
 Server Port    | 5432
 Client Address | ::1/128
 Client Port    | 46824
 Session PID    | 27598
(9 rows)

Connection 4 (127.0.0.1):
[postgres@localhost bin]$ ./psql -h 127.0.0.1
psql (17devel)
Type "help" for help.

postgres=# \conninfo
You are connected to database "postgres" as user "postgres" on host "127.0.0.1" at port "5432".
postgres=# \conninfo+
Current Connection Information
   Attribute    |    Value
----------------+--------------
 Database       | postgres
 User           | postgres
 Server Version | 17devel
 Server Address | 127.0.0.1/32
 Server Port    | 5432
 Client Address | 127.0.0.1/32
 Client Port    | 34876
 Session PID    | 27624
(8 rows)

Regards,
Maiquel O. Grassi.

Commits

  1. psql: Change new \conninfo to use SSL instead of TLS

  2. Change \conninfo to use tabular format

  3. Update extension lookup routines to use the syscache

  4. Improve COPY TO performance when server and client encodings match

  5. doc: Remove superfluous bracket in synopsis

  6. Remove psql support for server versions preceding 9.2.