MySQL is known for its willingness to accept invalid queries, data values. It can silently commit your transaction, truncate your data. Using GROUP_CONCAT with a small group_concat_max_len setting? Your result will be silently truncated (make sure to check the warnings though). Calling CREATE TEMPORARY TABLE? You get silent commit. Issuing a ROLLBACK on non-transactional involved [...]
Nothing new about this warning; but it's worth repeating: Using binlog-do-db is dangerous to your replication. It means the master will not write to binary logs any statement not in the given database. Ahem. Not exactly. It will not write to binary logs any statement which did not originate from the given database. Which is [...]
I've written shortly on this before. I like yum; I love apt-get; I prefer not to use them for MySQL installations. I consider a binary tarball to be the best MySQL installation format (source installations being a different case altogether). Why? I use yum and apt-get whenever I can and for almost all needs (sometimes [...]
I'm proud to announce mycheckpoint, a monitoring utility for MySQL, with strong emphasis on user accessibility to monitored data. mycheckpoint is a different kind of monitoring tool. It leaves the power in the user's hand. It's power is not with script-based calculations of recorded data. It's with the creation of a view hierarchy, which allows [...]
Unless specified otherwise, latin1 is the default character set in MySQL. What I usually find in schemes are columns which are either utf8 or latin1. The utf8 columns being those which need to contain multilingual characters (user names, addresses, articles etc.), and latin1 column being all the rest (passwords, digests, email addresses, hard-coded values etc.) [...]
When working with InnoDB, you have two ways for managing the tablespace storage: Throw everything in one big file (optionally split). Have one file per table. I will discuss the advantages and disadvantages of the two options, and will strive to convince that innodb_file_per_table is preferable. A single tablespace Having everything in one big file [...]
The two server variables, report_host and report_port, are not commonly used. One of the reasons, I suspect, is that they do not appear in any of the standard .cnf files provided with a MySQL installation. For a replication environment, I find these two variables to be very useful. Where are these variables used? Here's a [...]
Continuing Variables ambiguities in names and values, there are two more issues I wish to present. First, I've shown that variable values may be ambiguous. Thus, 1 and ON are interchangeable. But also 1 and YES. The important thing to note is that it's not always like that. You can't just swap 1 for ON [...]
Writing up some scripts, I see more and more ambiguities with regard to global variables. For one thing, the names ambiguity between the hyphen ('-') and the underscore ('_'). So wait_timeout and wait-timeout are the same variable. But just check out the many levels of inconsistency: Command line arguments (e.g. run mysqld with option variables) [...]
This is a short note that the MySQL User Group Meetings in Israel are established (well, re-established after a very long period). Thanks to Eddy Resnick from Sun Microsystems Israel who has set up the meetings. So far, we've had 2 successful meetings, and we intend to have more! First one was in Sun's offices [...]