On Thu, 2007-11-15 at 17:13 +, Gregory Stark wrote:
> DELETE
> FROM atable AS x
> USING (SELECT ctid FROM atable LIMIT 5) AS y
> WHERE x.ctid = y.ctid;
Have you tried to EXPLAIN this one ? Last time I tried to do something
similar it was going for a sequential scan on atable with a fi
"Abraham, Danny" <[EMAIL PROTECTED]> writes:
> Hi,
>
> I am wondering if I can do in PG Chunck Delete, like the Oracle example
> below.
>
> In Oracle we erase 50,000 records using the following:
>
> Delete where and ROWNUM < 5;
>
> Do we have such a feature in PG?
You can still use a subqu
[snip]
> With Oracle we do it with: delete ,tname> where and rownum <
> Y;
> Can we have the same goody on Postgres?
The attached message is Tom's response to a similar question, in any
case it would work fine in your case too (assuming you have postgres
8.2).
HTH,
Csaba.
--- Begin Message -
Say we have a FIFO of 800,000,000 records.
No primary key is required - this is only audit information. We do not
use it on Oracle too.
Based on a condition, 2,000,000 records should be deleted daily.
We have a background process that wakes up every X minutes and deletes Y
records.
On Thu, Nov 15, 2007 at 02:46:09PM +0100, Alexander Staubo wrote:
> On 11/15/07, Abraham, Danny <[EMAIL PROTECTED]> wrote:
> > With Oracle we do it with: delete ,tname> where and rownum < Y;
>
> You could create a temporary sequence:
>
> create temporary sequence foo_seq;
> delete from fo
On Thu, Nov 15, 2007 at 03:09:10PM +0200, Abraham, Danny wrote:
> THE problem is that the table does not have a primary key; Too
> expensive.
If the table doesn't have a primary key, you've designed it wrong.
But I'd like to see any evidence you have at all that having a primary key
is "too expen
The temporary sequence works perfectly for me.
Thanks
---(end of broadcast)---
TIP 9: In versions below 8.0, the planner will ignore your desire to
choose an index scan if your joining column's datatypes do not
match
On 11/15/07, Abraham, Danny <[EMAIL PROTECTED]> wrote:
> In Oracle we erase 50,000 records using the following:
>
> Delete where and ROWNUM < 5;
>
> Do we have such a feature in PG?
Just delete with a subselect:
delete from where in (
select from order by
limit 5);
For examp
On Thu, Nov 15, 2007 at 09:43:52AM -0500, Andrew Sullivan wrote:
> On Thu, Nov 15, 2007 at 03:33:04PM +0200, Abraham, Danny wrote:
> >
> > Based on a condition, 2,000,000 records should be deleted daily.
>
> Why not use that condition (which I presume is indexed) as the criterion for
> your dele
On Thu, Nov 15, 2007 at 03:33:04PM +0200, Abraham, Danny wrote:
>
> Based on a condition, 2,000,000 records should be deleted daily.
Why not use that condition (which I presume is indexed) as the criterion for
your delete? I mean, how else are you getting those row numbers in Oracle.
They have
On Thu, Nov 15, 2007 at 04:18:27PM +0200, Abraham, Danny wrote:
> The temporary sequence works perfectly for me.
You may want to read my other message and test again. You are well
into implementation details here and the trick that was suggested will
(with the current version of PG delete the fir
On 11/15/07, Abraham, Danny <[EMAIL PROTECTED]> wrote:
> With Oracle we do it with: delete ,tname> where and rownum < Y;
You could create a temporary sequence:
create temporary sequence foo_seq;
delete from foos where nextval('foo_seq') < 5;
I'm not sure how fast nextval() is, even o
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