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

On 20/1/21 5:11 am, Ron wrote:
> On 1/19/21 1:55 PM, David G. Johnston wrote:
>> On Tuesday, January 19, 2021, Ron <ronljohnsonjr(at)gmail(dot)com
>> <mailto:ronljohnsonjr(at)gmail(dot)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