Is there any quick hacks to do this quickly? There's around
20-30million
rows of data.
I want to change a column type from varchar(4) to varchar()
table size is ~10-15GB (and another 10-15G for indexes)
What would be the preferrred way of doing it? SHould I be dropping the
indexes 1st to make
Ow Mun Heng schrieb:
Is there any quick hacks to do this quickly? There's around
20-30million
rows of data.
I want to change a column type from varchar(4) to varchar()
table size is ~10-15GB (and another 10-15G for indexes)
What would be the preferrred way of doing it? SHould I be dropping t
On Thu, 2008-07-10 at 10:36 +0200, Mario Weilguni wrote:
> Ow Mun Heng schrieb:
> >
> > I want to change a column type from varchar(4) to varchar()
> >
> >
> Example:
> {OLDLEN} = 4
> {NEWLEN} = 60
>
> update pg_attribute
>set atttypmod={NEWLEN}+4
> where attname='the-name-of-the-column'
>
On a Linux system, if the total memory is 4G and the shmmax is set to 4G, I
know it is bad, but how bad can it be? Just trying to understand the impact the
"shmmax" parameter can have on Postgres and the entire system after Postgres
comes up on this number.
What is the reasonable setting for
In response to Jessica Richard <[EMAIL PROTECTED]>:
> On a Linux system, if the total memory is 4G and the shmmax is set to 4G, I
> know it is bad, but how bad can it be? Just trying to understand the impact
> the "shmmax" parameter can have on Postgres and the entire system after
> Postgres
On Thu, Jul 10, 2008 at 4:53 AM, Jessica Richard <[EMAIL PROTECTED]> wrote:
> On a Linux system, if the total memory is 4G and the shmmax is set to 4G, I
> know it is bad, but how bad can it be? Just trying to understand the impact
> the "shmmax" parameter can have on Postgres and the entire sys
I just wanted to add to my previous post that shared_memory generally
has a performance envelope of quickly increasing performance as you
first increase share_memory, then a smaller performance step with each
increase in shared_memory. Once all of the working set of your data
fits, the return star
Ow Mun Heng wrote:
> This is what I see on the table
>
> NEW attypmod = -1
> OLD attypmod = 8
8 means varchar(4) which is what you said you had (4+4)
-1 means unlimited size.
--
Alvaro Herrerahttp://www.CommandPrompt.com/
The PostgreSQL Company - Command Promp
Some corrections:
On Thu, Jul 10, 2008 at 6:11 AM, Scott Marlowe <[EMAIL PROTECTED]> wrote:
SNIP
> If you commonly have 100 transactions doing that at once, then you
> multiply much memory they use times 100 to get total buffer >> SPACE << in
> use,
> and the rest is likely NEVER going to get u
On Thu, 2008-07-10 at 09:57 -0400, Alvaro Herrera wrote:
> Ow Mun Heng wrote:
>
> > This is what I see on the table
> >
> > NEW attypmod = -1
> > OLD attypmod = 8
>
> 8 means varchar(4) which is what you said you had (4+4)
> -1 means unlimited size.
>
This is cool.
If it were this simple a
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