How I compact WAL files?

Question

I like compact WAL files. Actually I do:

archive_command = 'cp "%p"C:\\%f"'

What is the best way to do it?

Answer 1

Going by your other questions, it sounds like you have a short archive_timeout so your WAL archives are mostly empty, but are still the full pre-allocated 16MB file.

On most platforms you just gzip them, e.g.

archive_command = 'gzip -c < "%p" > /archive/path/%f"'

On Windows this won't work natively due to the lack of the gzip command. You'll need to install a compression utility that's usable from the command line, since the Windows zip support isn't directly usable from the commandline.

I suggest installing 7-zip, then using it in your archive_command, with something like (untested):

archive_command = '%PROGRAMFILES%\7zip\7z.exe a "C:\\TheWALArchive\%f" "%p"'

Note that your restore_command will need a corresponding decompression step.