Re: triggers, transactions and locks

>> Is there a way to use locks within a trigger? My example below gives
>> the error:
>> ERROR:  unexpected error -8 in EXECUTE of query "BEGIN"
>> CONTEXT:  PL/pgSQL function "insert_into_t1" line 6 at
>execute statement

>Can you tell us what you're trying to do?  Why do you want to
>lock the table but not hold the lock until the outer transaction ends?
Hi Michael,

In my trigger after an update, the trigger scans the table and creates a
row new row with one the counters going from i=i+1. However, I've found
that if two updates occur together then two identical rows can be
created. Hence, I thought of locking the table within the trigger.

I presume from your email that the best way would be to lock the table
from the beginning of the transaction?

Thanks

Colin

>
>--
>Michael Fuhr
>http://www.fuhr.org/~mfuhr/
>