[TYPO3-dev] Idea: add transaction support to t3lib_db

[Dmitry Dulepov]

Hi!

Jigal van Hemert wrote:
> INSERT and UPDATE queries lock a table in many cases already with
> non-transactional engines. These locks don't take a long time, but it
> can slow down the system indeed.

Not exactly true. This was a majopr problem in indexed search: the table 
was locked when somebody made a search and another process did INSERT. The 
read was going on but the lock was placed for INSERT, which locked the 
table for all other INSERTs as weel *and* for reads. Thus the whole site 
was locked for minutes:
- read (not locked)
- INSERT (lock, waiting for read to finish)
- read (wait on INSERT lock)
- insert (wait on INSERT lock)
- read (wait on INSERT lock)
- insert (wait on INSERT lock)
- ....

That was solved by using InnoDB. But for MyISAM it was a nightmare...

-- 
Dmitry Dulepov
TYPO3 core&security team member
E-mail: dmitry.dulepov at typo3.org
Web: http://dmitry-dulepov.com/