(Bjørn Hansen) One of the NTP Pool server operators emailed recently and told that his server was unavailable for a few hours because he had changed some firewall rules remotely and managed to lock everyone out. Oops!
Tag: Open Source
Using GROUP BY WITH ROLLUP for Reporting Performance Optimization
(Peter Zaitsev) Quite typical query for reporting applications is to find top X values. If you analyze Web Site logs you would look at most popular web pages or search engine keywords which bring you most of the traffic. If you’re looking at ecommerce reporting you may be interested in best selling
How MySQL Treats Security Vulnerabilities
(Kaj Arnö) The phrase “security vulnerability” gives most of us the creeps. We are afraid of them. Looking at them rationally, they share a trait with other bugs: All are a pain, but some are a bigger pain than others. And instead of trying to avoid the evil by not talking about it, let’s take a loo
How do I… Stress test MySQL with mysqlslap?
(Melonfire) One of the interesting new tools in MySQL 5.1.4 is mysqlslap, a load emulator that lets you see how well a particular query set or table engine performs under high-load conditions.
MySQL Proxy: Adaptive Slow Query Log
(Jan Kneschke) Kris brought up a simple question: Why do I have to set the slow-query-time by hand ? Why can’t the server figure out the normal query time and tell me when something is unusual slow ?
MySQL Database To Get Replication Monitoring, Multi-Concurrency Features
(Charles Babcock) The MySQL open source database by the end of September will offer a beta version that shows several capabilities normally associated with more sophisticated database systems, such as online database replication monitoring.
Enabling/Disabling query log without server restart in MySQL 5.0
(Peter Zaitsev) General query logging can be very handy in MySQL on profuction server for various debugging needs. Unfortunately you can’t switch it on and off without restarting server until MySQL 5.0.
Using the SIGNAL Statement for Error Handling
(Guy Harrison and Steven Feuerstein) In this conclusion to a three-part series, you will learn about the SIGNAL statement and its uses for creating your own error statements.
Query Profiling with MySQL: Bypassing caches
(Peter Zaitsev) Quite frequently I run into question like this “I’m using SQL_NO_CACHE but my query is still much faster second time I run it, why is that?
InnoDB Deadlock – Next Key Locking
(Parvesh Garg) So you use InnoDB, have indexes on your table, think of row level locking and concurrent queries, feel good and go to sleep. All this while forgetting that even UPDATE and SELECT …. FOR UPDATE statements will (or may) also use the same index for scanning or updating. Then what? You