can you reduce the UDF just to return 1; ? that should give you a clue what is going on. Random values usualy point to two suspects 1. mixing 32bit and 64bit 2. using void instead of int
re, wh Am 04.11.2012 23:23, schrieb Stefan Kuhn: > Hi all, > I have a weired (for me at least) problem with a user defined function, > written in C. The function seems to return different results in different > runs (the code of the function does not contain random elements). Basically, > the function calculates a score based on a column in a table and an input > value. So I do something like this: > select * from table order by udf(column, 'input_value') desc; > For my understanding, this should give the same result always. But if I run > many statements (execution is from a java program and I can do it in parallel > threads) so that they overlap (the udf on a large table takes 5-10 s on a > slow machine), the results of some queries are different. If I have enough > time between statements, it seems to work, i. e. the result is always the > same. I would have thought the statements are independent, even if executed > on different jdbc connections in parallel. > Does somebody have an idea? > Or could somebody give an idea on debugging? Normally I would try to debug > the > code to see what goes on, but how can I do this in a udf? Can I log in the > udf? > Thanks for any hints, > Stefan > -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe: http://lists.mysql.com/mysql
