Re: BUG #2694: Memory allocation error when selecting array - Mailing list pgsql-bugs

From Joe Conway
Subject Re: BUG #2694: Memory allocation error when selecting array
Date
Msg-id 4535FB38.2020508@joeconway.com
Whole thread Raw
In response to Re: BUG #2694: Memory allocation error when selecting array of empty arrays  (Tom Lane <tgl@sss.pgh.pa.us>)
Responses Re: BUG #2694: Memory allocation error when selecting array  (Tom Lane <tgl@sss.pgh.pa.us>)
List pgsql-bugs
Tom Lane wrote:
> "Vitali Stupin" <Vitali.Stupin@ria.ee> writes:
>
>>The error "invalid memory alloc request size 4294967293" apears when
>>selecting array of empty arrays:
>>select ARRAY['{}'::text[],'{}'::text[]];
>
> I can get a core dump off it too, sometimes.  The problem is in
> ExecEvalArray, which computes the dimension of the result as [1:2]
> even though there are no elements to put in it.
>
> Joe, what do you think about this?  Offhand I think that the only
> workable definition is that this case yields another zero-dimensional
> array, but maybe there is another choice?

Sorry for the slow response -- I'm at the airport just heading home from
a marathon 30 day business trip.

I think producing another zero-dimensional result is the only way that
makes sense unless/until we change multidimensional arrays to really be
arrays of array-datatype elements. Right now they're two different things.

> We should probably check all the other array operations to see if they
> have comparable problems.

Yes -- I'll see if I can find the time over the next couple weeks while
home.

Joe

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