Re: alter table is taking a long time

Hi,

I recently had to do something similar: change one column from INT to BIGINT in a table which has inherited to a depth of 3 and where some of the child tables had millions of records.

All affected tables have to be rewritten for such a command. One consequence of this is that you (temporarily) need up to twice the amount of disk space that the tables are currently occupying. Another is that it takes a long time - for me I ran it overnight and it took at least 6 hours. Of course it depends on your hardware.

I could not find any way to check on the progress of this query .. maybe someone else can help with that.

I would not recommend restarting postgres. Can't you just cancel the query (control-C on psql if that is how you sent the command) or failing that send the postgresql backend process a SIGINT (not the master backend of course, the postgres backend that is executing the ALTER command)? It should roll back to the state as before the command was entered.

Regards // Mike

-----Original Message-----
From: stanciutheone(at)gmail(dot)com [mailto:stanciutheone(at)gmail(dot)com]
Sent: Saturday, 7 November 2009 4:55 PM
To: pgsql-general(at)postgresql(dot)org
Subject: Re: alter table is taking a long time

There is no one that can tell me what i can do here, or they will do
here

I'm thinking to restart postgrsql but what will happen with my table
that i'm just altering just a filter

On Nov 7, 2:38 am, "stanciuthe(dot)(dot)(dot)(at)gmail(dot)com" <stanciuthe(dot)(dot)(dot)(at)gmail(dot)com>
wrote:
> Hi
> i have main table where and that table i have inherited 64 times, but
> today i needed some extra space to a column so i have run an alter
> table to one of my columns
>
> the query is running for over 4 hours and i don't have a clue when it
> will stop, the storage of this 64 table has around 30 and milions of
> records,
>
> Any advices on what i should need to do next,
>
> Regards