Re: TIL: In pg_dump, beware the combo of "-Fd" and "-Z"

On 1/19/21 1:55 PM, David G. Johnston wrote:

On Tuesday, January 19, 2021, Ron <ronljohnsonjr@gmail.com> wrote:

For a project using 9.6, I have this command backing up a database:
So, for the 12 project, I copied it over, removing the "0", since I want these backups compressed.

The versions in use doesn’t seem pertinent to the observation - this behavior hasn’t changed (at least in the docs).

 

Since the -Z default is "6"

It is?  Where do you see this?

https://www.postgresql.org/docs/12/app-pgdump.html

"-Z 0..9"
"the default is to compress at a moderate level."

It doesn't say "6", but every other bit of software I've used defaults to level 6.

A quick look at the `pg_dump` source code indicates that:

* `-Z` requires an argument, and

* the argument is converted to an integer with the `atoi()` C function

This means that `-Z` actually took `-v` as its argument, which `atoi()` converts to integer 0. That explains what you saw, and I'm also guessing you did NOT get verbose output from your second command.
Best Regards,
Adrian