> A general-case good design for this is to have status fields, as > suggested, and who-owns-this-row fields. Set the rows initially to > un-owned (NULL), and status 'new' or similar.
The "get_lock" approach was ultimately successful, and I think better than using a status field as it is entirely self-managing. If one of the compute clients die, its locks are immediately released and another compute client can immediately pick up where it left off. I just had to separate the "get_lock" query from the "select" query for it to work. I also optimized the select query by adding a "distance" column, and setting that to "sqrt(pow(x, 2) + pow(y, 2))" and then ordering the select clause by that column as opposed to running the function each time and that sped up the select query to less than a second per run. I also plan on changing the limit clause from "limit %d, 1" to something like "limit 500" and then iterating through the results until I get one that succeeds, as that is more efficient than running multiple select queries. Anyhow, thanks for all the good suggestions and pointers - it all worked out in the end! Tim Gustafson 831-332-1496 t...@tgustafson.com http://tgustafson.com/ -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe: http://lists.mysql.com/mysql?unsub=arch...@jab.org
