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Re: R: GSOC 2015 :UDFs returning arrays

 

Hi,

I am not sure of the point of that mdev.  First, arrays are not table
functions.  Arrays are data structures.  A table function can certainly
return all the items in an array data structure as rows (which would be
part of #820)  but that doesn't mean that a table function could replace an
ARRAY data type.  Arrays also have to be able to be passed to stored
routines and stored in tables too, or they are virtually useless.

Second, WL#820, which far precedes that mdev, adds real table functions
without magic "pretend" storage engine as suggested in the later mdev.  In
any case, you can't return an array or table, from a UDF, without changing
the UDF interface which will break other UDF.  The UDF interface IS NOT
VERSIONED.

wl#820 adds external stored procedures and doesn't modify the udf interface
(UDF can rot)  The mysql bug link I sent makes item functions internally
pluggable, so they could support table functions as well and provide a
replacement for UDF.  Add an ARRAY data type and implement these patches
(which are from Antony Curtis) and you'll get what you want.

It would be a real shame to replace wl#820 work with some half-backed UDF
that has not access to internals.

--Justin

On Tue, Mar 10, 2015 at 12:04 PM, Federico Razzoli <federico_raz@xxxxxxxx>
wrote:

> This JIRA task doesn't mention GSoC, but it seems to be what you are
> asking for:
>
> https://mariadb.atlassian.net/browse/MDEV-5199
>
> Hope it helps.
>
> Federico
>
>
> --------------------------------------------
> Mar 10/3/15, Delveri chick <chickdelveri@xxxxxxxxx> ha scritto:
>
>  Oggetto: [Maria-discuss] GSOC 2015 :UDFs returning arrays
>  A: maria-discuss@xxxxxxxxxxxxxxxxxxx
>  Data: Martedì 10 marzo 2015, 19:28
>
>  Hi My name is Blessing
>  Atie and i would love to participate in the Google summer of
>  code 2015 under Mariadb. I am interested in the project UDF
>  returning arrays. I have build mariadb from source and and i
>  also  ran  the test suites. I am currently studing the
>  sql/sql.** files to understand UDF's and  i also
>  downloaded some ebook on mysql internals and mysql plugin
>  development  which im reading while hoping to find a
>  breakthrough on this project in them. I would love to know
>  if there are any bugs related to this task on JIRA I could
>  work on as a means of preparing for the project.Please give me the
>  link.
>  Regards
>  -----Segue allegato-----
>
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