"Brian J. France" <postgresql@firehawksystems.com> writes:
> I am getting a few of these errors in my web logs and didn't know what I could do to stop it.
> NOTICE: Deadlock detected -- See the lock(l) manual page for a possible cause.
> Error in query "UPDATE <table> SET <field> = <value> WHERE <field2> = <value2>" : ERROR: WaitOnLock: error on wakeup
-Aborting this transaction
> Is this due to the hash index on field2 or due to the has index in general?
Don't use hash indexes for concurrent applications. I don't really know
of any reason for preferring a hash index over a btree index in any case.
regards, tom lane