Commands tagged postgresql (12)

  • Get a listing of all of your databases in Postgres and their sizes, ordering by the largest size first. Requires that you give the -d parameter a valid database name that you can connect to. Show Sample Output

    psql -c "SELECT pg_database.datname, pg_database_size(pg_database.datname), pg_size_pretty(pg_database_size(pg_database.datname)) FROM pg_database ORDER BY pg_database_size DESC;" -d <ANYDBNAME>
    bbbco · 2011-11-30 15:22:48 6
  • It's certainly not nicely formatted SQL, but you can see the SQL in there...

    sudo tcpdump -nnvvXSs 1514 -i lo0 dst port 5432
    ethanmiller · 2009-12-18 17:12:44 5
  • This command will "su" the execution of the command to the postgres user(implies that you are already logger as root), and export the result of the query to a file on the csv format. You'll need to adequate the fields and database information to one of your choice/need. Show Sample Output

    # su -c "psql -d maillog -c \"copy (select date,sender,destination,subject from maillog where destination like '') to '/tmp/mails.csv' with csv;\" " postgres
    Risthel · 2013-02-13 13:03:17 4
  • This command drops all the tables of the 'public' schema from the database. First, it constructs a 'drop table' instruction for each table found in the schema, then it pipes the result to the psql interactive command. Useful when you have to recreate your schema from scratch in development for example. I mainly use this command in conjunction with a similar command which drop all sequences as well. Example : psql -h <pg_host> -p <pg_port> -U <pg_user> <pg_db> -t -c "select 'drop table \"' || tablename || '\" cascade;' from pg_tables where schemaname='public'" | psql -h <pg_host> -p <pg_port> -U <pg_user> <pg_db> psql -h <ph_host> -p <pg_port> -U <pg_user> <pg_db> -t -c "select 'drop sequence \"' || relname || '\" cascade;' from pg_class where relkind='S'" | psql -h <ph_host> -p <pg_port> -U <pg_user> <pg_db> See it scripted here :

    psql -h <pg_host> -p <pg_port> -U <pg_user> <pg_db> -t -c "select 'drop table \"' || tablename || '\" cascade;' from pg_tables where schemaname='public'" | psql -h <pg_host> -p <pg_port> -U <pg_user> <pg_db>
    cuberri · 2013-12-11 15:39:56 14
  • This command drops all the sequences of the 'public' schema from the database. First, it constructs a 'drop sequence' instruction for each table found in the schema, then it pipes the result to the psql interactive command. See it scripted here :

    psql -h <ph_host> -p <pg_port> -U <pg_user> <pg_db> -t -c "select 'drop sequence \"' || relname || '\" cascade;' from pg_class where relkind='S'" | psql -h <ph_host> -p <pg_port> -U <pg_user> <pg_db>
    cuberri · 2013-12-11 15:42:34 6
  • In a multiple PostgreSQL server environment knowing the servers version can be important. Note that psql --version returns just the local psql apps version which may not be what you want. This command dumps the PostgreSQL servers version out to one line. You may need to add more command line options to the psql command for your connection environment. Show Sample Output

    psql -h <SERVER NAME HERE> -c 'SELECT version();' | grep -v 'version\|---\|row\|^ *$' | sed 's/^\s*//'
    pnelsonsr · 2014-03-17 18:36:40 7
  • -t, --tuples-only print rows only Show Sample Output

    psql -h <SERVER NAME HERE> -t -c 'SELECT version();' |head -1
    hxre · 2014-04-25 08:26:23 8
  • Without using a pipe. -X ignores the user's .psqlrc configuration file -A sets un-aligned table output mode -t prints rows only (no headers or footers) Show Sample Output

    psql -X -A -t -c "SELECT version();"
    malathion · 2014-05-01 18:10:20 7
  • Replace the credentials to psql if necessary, and the my-query part with your query. Show Sample Output

    psql -U quassel quassel -c "SELECT message FROM backlog ORDER BY time DESC LIMIT 1000;" | grep my-query
    Tatsh · 2014-10-12 19:53:06 7
  • to kill, use `kill PID` Credit: user Craig Ringer on, recommends to kill the process rather than deleting when there is an orphan Postgresql server process. Show Sample Output

    cat /usr/local/var/postgres/
    ctcrnitv · 2017-02-07 02:38:28 19
  • Continuously watches postgres, showing the instances using the most RAM at the top. Show Sample Output

    watch -n 1 '{ ps aux | head -n 1; ps aux --sort -rss | grep postgres | grep -v grep; } | cat'
    carbocation · 2017-05-14 17:01:44 16
  • Check if SSH tunnel is open and open it, if it isn't. NB: In this example, 3333 would be your local port, 5432 the remote port (which is, afaik, usually used by PostgreSQL) and of course you should replace REMOTE_HOST with any valid IP or hostname. The example above let's you work on remote PostgreSQL databases from your local shell, like this: psql -E -h localhost -p 3333

    while true; do nc -z localhost 3333 >|/dev/null || (ssh -NfL 3333:REMOTE_HOST:5432 USER@REMOTE_HOST); sleep 15; done
    rxw · 2015-09-21 02:25:49 11

What's this? is the place to record those command-line gems that you return to again and again. That way others can gain from your CLI wisdom and you from theirs too. All commands can be commented on, discussed and voted up or down.

Share Your Commands

Check These Out

take a look to command before action
add |sh when you agree the list, I often use that method to prevent typos in dangerous or long operations

Find Duplicate Files (based on size first, then MD5 hash)
This dup finder saves time by comparing size first, then md5sum, it doesn't delete anything, just lists them.

Find which jars contain a class

Battery real life energy vs predicted remaining plotted
This time I added a print to reemaining energy, every minute, time stamped. The example shown here is complete and point to large discrepancies as time passes, converging to accuracy near the end.

Recursively remove 0kb files from a directory

Simulate typing but with mistakes
The output will show jerk, then wonderful person since echo parses the \b character.

Backup all MySQL Databases to individual files

Get AWS temporary credentials ready to export based on a MFA virtual appliance
You might want to secure your AWS operations requiring to use a MFA token. But then to use API or tools, you need to pass credentials generated with a MFA token. This commands asks you for the MFA code and retrieves these credentials using AWS Cli. To print the exports, you can use: `awk '{ print "export AWS_ACCESS_KEY_ID=\"" $1 "\"\n" "export AWS_SECRET_ACCESS_KEY=\"" $2 "\"\n" "export AWS_SESSION_TOKEN=\"" $3 "\"" }'` You must adapt the command line to include: * $MFA_IDis ARN of the virtual MFA or serial number of the physical one * TTL for the credentials

Create a new file

Convert PDF to JPG
(relies on 'imagemagick') This command will convert all .pdf files in a directory into a 800px (wide or height, whichever is smaller) image (with the aspect ratio kept) .jpg. If the file is named 'example1.pdf' it will be named 'example1.jpg' when it is complete. This is a VERY worthwhile command! People pay hundreds of dollars for this in the Windows world. My .jpg files average between 150kB to 300kB, but your's may differ.

Stay in the loop…

Follow the Tweets.

Every new command is wrapped in a tweet and posted to Twitter. Following the stream is a great way of staying abreast of the latest commands. For the more discerning, there are Twitter accounts for commands that get a minimum of 3 and 10 votes - that way only the great commands get tweeted.


Subscribe to the feeds.

Use your favourite RSS aggregator to stay in touch with the latest commands. There are feeds mirroring the 3 Twitter streams as well as for virtually every other subset (users, tags, functions,…):

Subscribe to the feed for: