Re: Slotification of partition tuple conversion - Mailing list pgsql-hackers

From Andres Freund
Subject Re: Slotification of partition tuple conversion
Date
Msg-id 20181002180237.7cptyi4xqfzvmjh7@alap3.anarazel.de
Whole thread Raw
In response to Re: Slotification of partition tuple conversion  (Amit Langote <Langote_Amit_f8@lab.ntt.co.jp>)
Responses Re: Slotification of partition tuple conversion  (Andres Freund <andres@anarazel.de>)
List pgsql-hackers
On 2018-10-02 18:35:29 +0900, Amit Langote wrote:
> Hi,
> 
> I looked at the patch.  Some comments.
> 
> On 2018/10/02 16:35, Andres Freund wrote:
> > I wasn't quite happy yet with that patch.
> > 
> > - ConvertTupleSlot seems like a too generic name, it's very unclear it's
> >  related to tuple mapping, rather than something internal to slots. I
> >  went for execute_attr_map_slot (and renamed do_convert_tuple to
> >  execute_attr_map_tuple, to match).
> > 
> >  I'd welcome a better name.
> 
> do_convert_tuple -> convert_tuple_using_map
> ConvertTuplSlot  -> convert_tuple_using_map_slot

I think my name is more descriptive, referencing the attr map seems
better to me.


> > - I disliked inheritence_tupconv_map, it doesn't seem very clear why
> >  this is named inheritence_* (typo aside). I went for
> >  convert_tuples_by_name_map_if_req() - while I think this sounds
> >  too much like it converts tuples itself it should be renamed with the
> >  rest of the convert_tuples_by_* routines.
> > 
> >  I'd welcome a better name.
> 
> Agree about doing something about the convert_* names.  A comment near the
> beginning of tupconvert.c says all of these convert_* routines are meant
> as conversion "setup" routines:

I'll try to tackle that in a separate commit.


> /*
>  * The conversion setup routines have the following common API:
> 
> So, maybe:
> 
> convert_tuples_by_position -> get_conversion_map_by_position
> convert_tuples_by_name     -> get_conversion_map_by_name
> convert_tuples_by_name_map -> get_attr_map_for_conversion
> convert_tuples_by_name_map_if_req -> get_attr_map_for_conversion_if_req

s/get/build/? I'm also not a fan of the separation of attr and
conversion map to signal the difference between tuples and slots being
converted...


> I noticed the comment at the top of tupconvert.c requires updating:
> 
>  * of dropped columns.  There is some overlap of functionality with the
>  * executor's "junkfilter" routines, but these functions work on bare
>  * HeapTuples rather than TupleTableSlots.
> 
> Now we have functions that manipulate TupleTableSlots.

Heh.  I think I'll just drop the entire sentence - I don't really think
there's much of an overlap to junkfilters these days.

Greetings,

Andres Freund


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