[TYPO3-english] Duplicate cHash values

[Dmitry Martynenko]

Hi Dan,

DO> I think the 32 char value must be used, to prevent collisions and
DO> guarantee (almost) the uniqueness. How slow does it make the table 
DO> seeks? And what table are we talking about - I think 
DO> tx_realurl_chashcache only looks up by spurl_hash.

I write yesterday about it in another thread, quotation below.

-----------------------------------------------------------------
 Our server begun to increase time for all SQL queries and
 I try to log slow queries (> 100 ms) from class.t3lib_db.php

 Most of them was like:
 SELECT /*! SQL_NO_CACHE */ content
 FROM tx_realurl_urlencodecache
 WHERE url_hash='43d5475f5d7dc35690cb8ab3d7683679' AND tstamp>1232035875

 This table has more then 450 000 records.
 It's  index size greater than 30 Mb.
 I think big index size and long key length take lot of time to search.
-----------------------------------------------------------------

May be it is need more testing.
But I think it is axiom: less data and shorter keys -> more speed to SELECT.

-- 
Dmitry Martynenko
Developer

Web: http://realt.by