Hello Rosen, Lets say you are working against mysql... 2000 records in table 1 and 500.000 records in table 2 is few information... and it's working 'cause you don't have 50000 records in table 1 and 3.000.000 records in table 2. But, I personally advise you to listen what Peter is telling you. R> If I perform "LOCK <fictive table>" should be MySQL waiting until another process R> unlocks this table ( if another user is appending data ) and then to lock R> table ? If you lock a table, then all process trying to access the table locked will have to wait until the table is released. But you'll have to deal with times of expiration. R> Yes, it will be better, but this way it's impossible, because this is a R> existing database with more than 2000 records in table 1 and 500 000 records R> in table 2 - and I should change logic of all software for this. R> I have an idea to try something - whould be working ? : R> I want to create some fictive table with one record and before start R> appending data in table 1 and table 2 to lock this fictive table. R> Thanks in advance, R> Rosen -- Best regards, Pablo -- PHP Database Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php