Re: pg_dump estimation

Sam Mason wrote:
> On Tue, Jun 24, 2008 at 11:13:14PM -0500, Marcelo Martins wrote:
>
>> is there a way to find out / calculate / estimate how big a pg_dump
>> using plain text format for a DB will be ?
>>
>
> How about simply doing:
>
>   pg_dump | wc -c
>
>
>   Sam
>
>
Hi Marcelo,

If (using Sam's suggestion) the reported size of bytes is larger than
(or even close to) the current free space, you may want to plug in an
external drive (USB or otherwise) and mount it, then do the dump to it.

If you intend to upgrade postgreSQL to 8.3.3, I think it may be
advisable to first install postgreSQL 8.3.3 hopefully from source as you
can have more control on where the executable will be placed (the idea
is to avoid at least initially overwriting the current executables for
postgres you have already deployed) use the --prefix=/your/path option
to facilitate isolated installation. Then use pg_dump (or pg_dumpall) of
the new postgreSQL installation to take the dump. In simpler words, use
8.3.x pg_dump to make a dump of a running instance of postgreSQL 7.x for
later restore on postgreSQL 8.3.x.


Allan.