Re: Function array_agg(array)

2014-10-25 10:16 GMT+02:00 Ali Akbar <the.apaan@gmail.com>:

 makeArrayResult1 - I have no better name now

I found one next minor detail.

you reuse a array_agg_transfn function. Inside is a message "array_agg_transfn called in non-aggregate context". It is not correct for array_agg_anyarray_transfn

Fixed.

 

probably specification dim and lbs in array_agg_finalfn is useless, when you expect a natural result. A automatic similar to array_agg_anyarray_finalfn should work there too.

makeMdArrayResultArray and appendArrayDatum  should be marked as "static"

ok, marked all of that as static.

 

I am thinking so change of makeArrayResult is wrong. It is developed for 1D array. When we expect somewhere ND result now, then we should to use makeMdArrayResult there. So makeArrayResult should to return 1D array in all cases. Else a difference between makeArrayResult and makeMdArrayResult hasn't big change and we have a problem with naming. 

I'm thinking it like this:

- if we want to accumulate array normally, use accumArrayResult and makeArrayResult. If we accumulate scalar the result will be 1D array. if we accumulate array, the resulting dimension is incremented by 1.

- if we want, somehow to affect the normal behavior, and change the dimensions, use makeMdArrayResult.

Searching through the postgres' code, other than internal use in arrayfuncs.c, makeMdArrayResult is used only in src/pl/plperl/plperl.c:plperl_array_to_datum, while converting perl array to postgres array.

So if somehow we will accumulate array other than in array_agg, i think the most natural way is using accumArrayResult and then makeArrayResult.

ok, there is more variants and I can't to decide. But I am not satisfied with this API. We do some wrong in structure. makeMdArrayResult is now ugly.