You are only seeing views, not the actual tables. There are the standard index plus a few TS specific indexes

On Saturday, March 16, 2013, Maciej Jaros wrote:

Hi.

I've notice that there are no keys and so probably no indexes on toolserver databases. Is this intentional? I've used below queries - both show no keys/indexes on revision table:

SHOW COLUMNS FROM plwiki_p.revision;

SHOW INDEX FROM plwiki_p.revision;

I've also exported the whole schema and see no indexes at all... The same for random wiki on s2 - nlwiki_p.

At first I thought this might be do to the replication, but even with replication you need to select some stuff and only insert latest data. And besides those are read-only databases so selecting should occur far more frequently then inserting and so indexing is crucial for performance. Is it not?

Why am I asking this? Well from a month or so I received a lot of query kills which should never be killed. Why they should never be killed? Because they are (or should be) working only on indexes:

• revision.rev_id - should be PRIMARY KEY
• revision.rev_page - should be KEY / FOREIGN KEY

My query is:

SELECT /* SLOW_OK */ MIN(rev_id) as first_rev_id FROM revision WHERE rev_page IN (2,4,6,8,12,13,15,16,18,20,21,22,23,24,25,26,28,29,...) GROUP BY rev_page

I admit the IN list is rather large, but still...

Regards, Nux.