I am working on a C aggregate function that returns a numeric[] result. If I
execute the aggregate and return the results directly in my SQL, I get the
expected results. For example:
SELECT vec_agg_mean(nums) FROM measurements;
NOTICE: avg 0 = 1.23000000000000000000
NOTICE: avg 1 = 1.9700000000000000
NOTICE: avg 2 = 3.7000000000000000
vec_agg_mean
----------------------------------------------------------------
{1.23000000000000000000,1.9700000000000000,3.7000000000000000}
(1 row)
The NOTICE logs are are there to help me verify the computed result in the
aggregate final function, and they essentially do
DatumGetCString(DirectFunctionCall1(numeric_out, datum))
However if I nest the aggregate inside something, such as unnest(), I get what
appear to be just memory addresses:
SELECT unnest(vec_agg_mean(nums)) FROM measurements;
NOTICE: avg 0 = 1.23000000000000000000
NOTICE: avg 1 = 1.9700000000000000
NOTICE: avg 2 = 3.7000000000000000
unnest
----------------
94674302945040
94674302945052
94674302945064
(3 rows)
You can see the NOTICE logs are still the same. Passing the aggregate result to
any other function seems to expose the problem, for example:
SELECT ARRAY[vec_agg_mean(nums)]::numeric[] FROM measurements;
NOTICE: avg 0 = 1.23000000000000000000
NOTICE: avg 1 = 1.9700000000000000
NOTICE: avg 2 = 3.7000000000000000
array
--------------------------------------------------
{{94674302928624,94674302928636,94674302928648}}
(1 row)
Any ideas what I’m doing wrong here? The source is available here:
https://github.com/SolarNetwork/aggs_for_vecs/blob/9e742cdc32a113268fd3c1f928c8ac724acec9f5/vec_agg_mean.c
<https://github.com/SolarNetwork/aggs_for_vecs/blob/9e742cdc32a113268fd3c1f928c8ac724acec9f5/vec_agg_mean.c>
Cheers,
Matt Magoffin
