[TYPO3-core] RFC: improving index of sys_template

[Martin Kutschker]

Hi!

I suggest to change the index "parent" to KEY parent (pid,sorting). All 
SELECTs that have a pid in the WHERE have also sorting in the ORDER BY.

As a test you may use this and have a look at output of EXPLAIN:

create index parent2 on sys_template (pid,sorting);
EXPLAIn SELECT * FROM sys_template WHERE pid=1 AND deleted=0 AND hidden=0 
AND (starttime<=1157534861) AND (endtime=0 OR endtime>1157534861) ORDER BY 
sorting LIMIT 1;

The point is that now the "Using filesort" is gone and another few 
microseconds are saved by a tiny change of the code.

It probably makes sense to change other "parent" indices of tables with 
sorting columns as well (eg pages and tt_content), but I haven't 
investigated closely.

It's probably a trunk only change.

Masi