• Upgrading passwords from old_passwords to "new passwords"

    February 28, 2011

    You have old_passwords=1 in your my.cnf. I'm guessing this is because you used one of the my-small.cnf, my-large.cnf etc. templates provided with your MySQL distribution. These files can easily win the "most outdated sample configuration file contest". Usually it's no big deal: if some parameter isn't right, you just go and change it. Some variables, […]

  • Upgrading to Barracuda & getting rid of huge ibdata1 file

    February 15, 2011

    Some of this is old stuff, but more people are now converting to InnoDB plugin, so as to enjoy table compression, performance boosts. Same holds for people converting to Percona's XtraDB. InnoDB plugin requires innodb_file_per_table. No more shared tablespace file. So your ibdata1 file is some 150GB, and it won't reduce. Really, it won't reduce. […]

  • On generating unique IDs using LAST_INSERT_ID() and other tools

    February 2, 2011

    There's a trick for using LAST_INSERT_ID() to generate sequences in MySQL. Quoting from the Manual: Create a table to hold the sequence counter and initialize it: mysql> CREATE TABLE sequence (id INT NOT NULL); mysql> INSERT INTO sequence VALUES (0); Use the table to generate sequence numbers like this: mysql> UPDATE sequence SET id=LAST_INSERT_ID(id+1); mysql> […]

  • Generating Google line charts with SQL, part I

    February 1, 2011

    In this series of posts I wish to show how Google Charts can be generated via SQL. We discuss the Google Charts limitations which must be challenged, and work towards a simple chart. I'm going to present the algorithm I use in mycheckpoint, a MySQL monitoring utility, which generates Google charts by raw data using […]

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