[TYPO3-english] Duplicate cHash values

[Dan Osipov]

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

Dan Osipov
Calkins Media
http://danosipov.com/blog/

Dmitry Martynenko wrote:
> Hi guys!
> 
>>>> This is an extremely serious issue for us, so I can write a patch. I
>>>> don't know where to start though - so any guidance you can provide is 
>>>> appreciated.
>>> I am guessing > 
>>> http://www.typo3-unleashed.net/typo3apidocs/typo3api_4.2.0/html/d8/d11/class_8tslib__fe_8php-source.html#l01745 
>>>  => shortMD5
>>> and the DB field is probably too short
> 
> I can suppose one improvement for keep up speed!
> 
> I have analyzed similar problem in thread "[TYPO3-english] unwanted cHash is generated in 50% links from USER_INT plugin"
> and I discover that increase this values from 8-10 chars to full 32
> chars MD5 value has disadvantages.
> 
> For example seek by this 32 chars keys become slow on big tables.
> 
> May be better solution is to decrease key length - for example use 16
> byte (binary) MD5 value, instead of 32 chars value. In any case they are equal.
> Binary comparison is always faster then text comparison. Because text
> comparison also takes in account character sets and case sensitivity.
>