Re: array_agg crash?

Tom Lane wrote:
> "Chris Spotts" <rfusca@gmail.com> writes:
>
>>> many groups are you expecting in that query?  Does the plan for the
>>> array_agg query show hash or group aggregation?
>>>
>
>
>> GroupAggregate
>>
>
> Huh, there's no reason it should take much memory then.  Maybe you've
> found a memory leak.  Can you put together a self-contained test case?
>
>             regards, tom lane
>
What do you want specifically as far as details for the test case?  I
exported just the table that that was reading from.  Installed a new
clean virtual  machine ubuntu (jaunty) and then installed 8.4.0.
Imported the table and definition.  Ran the same query and the same
thing happened.

Table its selecting from is:
          Table "public.trip_ids_to_customer_upload_ids"
       Column       |  Type   | Modifiers | Storage | Description
--------------------+---------+-----------+---------+-------------
 trip_id            | bigint  |           | plain   |
 customer_upload_id | integer |           | plain   |
Indexes:
    "trips_customer_id" btree (trip_id, customer_upload_id)
Has OIDs: no

There is 3801347 rows in the table.  There are 3773039 distinct trip_id
values.  So you can see that the vast majority of rows here are just a
single  element array.