maria-developers team mailing list archive

[Sergey Petrunia <sergey@xxxxxxxxxxx>]

More input on the latest branch

* main/mdev21580.test is still there and the .result file is still too large.

* mysql-test/main/order_by_pack_big.result has got this:

+SELECT id, names, address INTO OUTFILE '/Users/varun/MariaDB/maria-dev2/mysql-test/var/mysqld.1/data/t1.txt' FROM t3 ORDER BY names, address;

please use 'evalp' to avoid this.

* The constant ORDER_BY_ORIGINAL_TRUNCATION is defined but not used anywhere?

On Wed, Feb 19, 2020 at 06:08:12PM +0300, Sergey Petrunia wrote:
> Hi Varun,
> 
> Please find some input below.
> 
> > commit f75829eebe96db55508cbc03c967e1c340da0cfc
> > Author: Varun Gupta <varun.gupta@xxxxxxxxxxx>
> > Date:   Fri Feb 7 02:30:06 2020 +0530
> > 
> >     MDEV-21580: Allow packed sort keys in sort buffer
> >     
> >     This task deals with packing the sort key inside the sort buffer, which  would
> >     lead to efficient usage of the memory allocated for the sort buffer.
> >     
> >     The changes brought by this feature are
> >       1) Sort buffers would have sort keys of variable length
> >       2) The format for sort keys inside the sort buffer would look like
> >          |<sort_length><null_byte><key_part1><null_byte><key_part2>.......|
> >           sort_length is the extra bytes that are required to store the variable
> >           length of a sort key.
> >       3) When packing of sort key is done we store the ORIGINAL VALUES inside
> >          the sort buffer and not the STRXFRM form (mem-comparable sort keys).
> >       4) Special comparison function packed_keys_comparison() is introduced
> >          to compare 2 sort keys.
> > 

BR
 Sergei
-- 
Sergei Petrunia, Software Developer
MariaDB Corporation | Skype: sergefp | Blog: http://s.petrunia.net/blog