Does Qlikview lock tables during load??

[#1]

I have an SQL SELECT (on MySQL via ODBC) that takes a long time while loading. The strange behaviour is that all the MySQL tables used for the load are locked, so that other user can't access this tables. So my question: Does Qlikview lock tables during an sql load? And if yes, where can I found the settings to turn of locking tables.

Any information is strongly appreciated.

Thomas

[#2]

Hi Rob, thanks a lot for your answer. I figured out that I probably do not have a problem of locking tables, but a problem on how MySQL handles internally single threads. So it can happen that a long time runnig sql statement blocks all threads which comming after the thread of the long time running sql (which could be of course of a locking the table touched by the sql statement).

But it's very interessting what you wrote about the used table engine. So I didn't know that the MyISAM engine provokes a table level locking.

I will investigate more deeper the behaviour, but for me it looks like I have to use a second server where there is no daily work done with.

Thanks a lot for your input, it will help me to figure out much better.

-Thomas

[#3]

You can select without locking in MySQL by calling the select like this:

SET TRANSACTION ISOLATION LEVEL READ UNCOMMITTED ;
SELECT * FROM TABLE_NAME ;
COMMIT ;

You can find more extensive documentation here:

http://dev.mysql.com/doc/refman/5.0/en/set-transaction.html

[#4]

Hi all,

I have a similar problem with a Informix database,

does anyone know how to solve it?