use Perl

• Some Suggestions (Score:2)

  by davorg (18) <dave@dave.org.uk> on 2006.06.27 9:17 (#48423) Homepage Journal

  • Two developers changing the database at the same time could change the same table, but this is always a problem.

  You need some centralised locking mechanism. One developer writes a file somewhere saying "I'm altering the database" (or "I'm altering this table" if you need finer control) and then no-one else can start an update until that file is removed.

  • Developers need to always remember to check their changes into the database along with source control.

  Can't you drive the changes from your source code control system? If it's not in source code control then it can't be released.

  • Remote servers with Mysql running MyISAM means no transactions.

  Bleah. Get a real database :-)

  • The SQL must not be active until such time that code is both committed to source control and updated on the server. This makes synchronization difficult.

  This is a harder problem. But perhaps it's easier if everything is in the source code control and all the releases (both code and database schemas) are all done automatically as part of the same update.

  Reply to This

  • Re:Some Suggestions (Score:2)

    by Ovid (2709)

    They've agreed to the centralized locking mechanism. As for using source control to manage the SQL, I'm not clear as to the best way to do that. I've checked out Cvs [cpan.org] on the CPAN and I can't get the tests to pass, regardless of whether I run them through CPAN.pm or do it by hand. I admit that having CVS contain all of the changes makes for a better solution, but trying to figure out the best way to cobble all of that together with the automated database upgrades sounds problematic. Would all of the update
    • Re:Some Suggestions (Score:1)

      by ajtaylor (1283)

      We can't even use InnoDB because of table space issues. When using InnoDB, we apparently have to allocate a fixed amount of space on the hard disk and if it's not used, it's wasted space.

      Did you know that by default InnoDB will automatically increase the size of the data file as needed? That means you can specify some relatively small size to start, and the DB will automatically change it as needed. See the documentation for autoextend [mysql.com].

      This probably a moot point anyway, but I wanted to point this f

      --
      "Perl users are the Greatful Dead fans of computer science." --slashdot comment
    • Re:Some Suggestions (Score:2)

      by bart (450)

      As you're on mysql, you can use lock table for some central table. I'm thinking about your config table that holds the version number, for example.