"Carlos H. Reimer" <carlos.reimer@opendb.com.br> writes:
>> BTW, have you looked into the theory that it's triggered by total
>> data volume rather than number of columns? That is, try selecting
>> all the columns but use LIMIT to reduce the number of rows fetched?
> The where clause limits the number of rows returned to 1 only. Only some
> primery keys are affected. For example, "Select * from table where pk=1"
> works and returns only one line but "select * from table where pk=2" locks
> and there is only one line with pk=2 in the table. I believe it is triggered
> by something else.
Hmm ... are some of the rows particularly wide? It could still be a
data-volume effect ...
regards, tom lane