So, from my reading of the MySQL 5.5 documentation and some experiments I did with colleagues, I understand that the following is the case: With InnoDB tables, a simple SELECT statement (one that ...
I have a rather basic question on transactions. Assume a table Account with a column amount. Now we have the following code: BEGIN $amount = SELECT amount FROM ACCOUNT WHERE id = 123; $amount = ...
We have an application that needs to be dumping rows into some tables at a much faster rate than it currently is. It is a dual processor xeon DB server with 48gb of ram and a 4 TB disk RAID 10 (for a ...
What is the difference between these 2 queries: start transaction; select * From orders Where id=1; UPDATE orders SET username="John" Where id=1; commit; And without transaction: select * From ...
I am running a MySQL server for tests on a VM (VMWare) with Debian as guest OS. The guest has four emulated CPU cores, so I set thread_concurrency to four. I am doing expensive joins on large tables, ...
I'm running into a problem where multiple MySQL updates being performed at the same time will lock up and takes several minutes to finish. I'm using InnoDB, so I'm confused as to why this could be ...