Re: Strange result using pg_dump gzip or split.

Hi Condor.

On Mon, Nov 10, 2014 at 12:34 PM, Condor <condor(at)stz-bg(dot)com> wrote:

> I have a database with 30 gb data and decide to archive it, postgresql is
> 9.3.5 x64_86, ext4 file system, kernel 3.14.18 Slackware 14.2 (current)
>

You should have a look at your tools, it seems you have a file size
problem....

> First I use gzip with : pg_dump logdb | gzip > log.sql.gz
> ...
>
$ gzip -l log.sql.gz

> compressed uncompressed ratio uncompressed_name
> 2170016226 3060688725 29.1% log_to.sql
> $ unzip -v log.sql.zip
> *** snip ***
> -------- ------- --- -------
> 20240557909 2170020867 89% 20 files
>

When you have this kind of problem, your first thing should be to pass
everything to hex:

2170016226=0x8157D1E2

2170020867=0x8157E403

Not a great difference there, this is normal, but on the uncompressed side:

20240557909=0x4B66E6755

3060688725=0xB66E6755

Mmmm, something phisy here, it seems gzip is using 32 bits only, so it gets
the things wrong. You can investigate more from there.
<http://www.postgresql.org/mailpref/pgsql-general> If you can spare the
disk space ( which seems to since you had it for the split/zip ) you should
try to gunzip it, and see how big it comes out ( I would recommenf 'gzip
-tv once to see what it does print, and then gunzip -cv > xxx to preserve
the input AND get verbose output ). The problem seems to be with gzip.

Francisco Olarte.