• More on variables ambiguities

    April 30, 2009

    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 […]

  • Variables ambiguities in names and values

    April 28, 2009

    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) […]

  • MySQL Conference: what's in a name?

    April 27, 2009

    This is just something that I realized this morning. There were some talks about how the "MySQL Users Conference & Expo" was renamed to "MySQL Conference & Expo" - thereby omitting the "Users" part. The talk was something like "So where are we, the users, in this story?" But what I've just recalled was a […]

  • MySQL Conference 2009 daily summary: Wednesday

    April 24, 2009

    Busy day again: today the Percona conference joined the regular schedule, so more stuff to attend! What did I attend? Maria In Depth, Monty Widenius, MontyProgram AB (Percona conference): Monty was discussing Maria performance-wise as opposed to his later session which was feature-wise). He did delve just a little bit into the decision making issues […]

  • MySQL Conference 2009 daily summary: Tuesday

    April 22, 2009

    Tuesday: day of the announcements and of numerous sessions. Busy day! The day started with the State of the Dolphin by Karen Padir (Sun Microsystems). She threw in some announcement, among which were MySQL 5.4, MySQL Cluster 7.0, better release cycles (matching the Enterprise), better code import from the community. Anyway, there is already a […]

  • MySQL Conference 2009 Community Awards

    April 22, 2009

    OK. That was a surprise! In retrospective, there have been some hints along the way. But I don't get hints. I'm the kind of man who, when watching a complicated movie, needs his girlfriend to explain him what goes on. I was utterly astonished and honored to find my name on the screen, and have […]

  • MySQL Conference 2009 daily summary: Monday

    April 21, 2009

    [See http://forge.mysql.com/wiki/MySQLConf2009MondayNotes] Monday: day of tutorials. Plenty of interesting tutorials on the Conference itself, plus a session with Mark Callaghan - it was hard to choose. I settled for two tutorials, which turned out to be three. Practical MySQL Plugin Development: As a C/C++/Java developer, I am very interested in the plugin API. I have […]

  • A note on Baron's command line tip for comparing result sets

    April 16, 2009

    A while ago Baron Schwartz published a MySQL command-line tip: compare result sets. A "SELECT * FROM world", for example, can be checksummed, compared with another checksum made on a replica, or otherwise another table which is supposed to contains the exact same data. I just wanted to note that if you're dealing with a […]

  • "Why?" of the week

    April 13, 2009

    As progress on oak-online-alter-table goes on, I'm encountering more and more limitations, for which I must find workarounds. Here's two: CREATE TABLE ... LIKE ... It works well, but it doesn't copy any foreign key constraints. So, if the original table is this: CREATE TABLE `dept_emp` ( `emp_no` int(11) NOT NULL, `dept_no` char(4) NOT NULL, […]

  • The depth of an index: primer

    April 9, 2009

    InnoDB and MyISAM use B+ and B trees for indexes (InnoDB also has internal hash index). In both these structures, the depth of the index is an important factor. When looking for an indexed row, a search is made on the index, from root to leaves. Assuming the index is not in memory, the depth […]

 
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