Обсуждение: postmaster hangs on delete from

Hi,

I have a serious issue with delete from.

When I do something like:

"delete from CALC_INVOICE_DATA where PERIOD_END>='2011-01-01'"

the postmaster takes 100% CPU and then nothing happens.

Doing any type of select on the same table works just fine, I have tried
various forms of vacuums and re-import of data but the result remains the
same.

Does anyone have a clue on what might be wrong here?

/Magnus

On Friday 13 March 2009, emsa@devdep.com wrote:
> Hi,
>
> I have a serious issue with delete from.
>
> When I do something like:
>
> "delete from CALC_INVOICE_DATA where PERIOD_END>='2011-01-01'"
>
> the postmaster takes 100% CPU and then nothing happens.
>

Some possibilities:

1) If it's using 100% CPU for a long period of time, you might have a
foreign key relationship to this table, and the key in the other (largish,
but not larger than RAM) table is not indexed, which is resulting in a seq
scan in cache for every row being deleted.

2) You have another on delete trigger that is expensive to run.

3) Some other backend is really using the 100% CPU and your delete is just
waiting for a lock on the table and not doing anything.

--
Even a sixth-grader can figure out that you can’t borrow money to pay off
your debt