Hi! >>>>> "Gordan" == Gordan Bobic <[email protected]> writes:
Gordan> How difficult would be be to implement working Gordan> auto-increment functionality on the BlackHole engine? Gordan> This would be really useful for what I'm trying to do at Gordan> the moment. Since it is not available and there are no Gordan> sequences in MariaDB and MySQL, I have to resort to a Gordan> hack such as a single-int-field table doing the Gordan> auto-increment, and an insert trigger on the blackhole Gordan> table to insert a null into the auto-increment Gordan> tracking table, get LAST_INSERT_ID() to set the Gordan> value in the auto-increment table, and then delete Gordan> the record. What problem is that you wanted to solve? Normally blackhole is used just for creating a slave of a slave that doesn't have to hold any data (only the logs). Gordan> Even with InnoDB log files and tablespace on tmpfs Gordan> this makes the performance nosedive by a factor of 4 Gordan> if the trigger doesn't bother cleaning up the Gordan> auto-increment table, and a factor of 13 if it Gordan> deletes the record immediately after inserting it. Gordan> The actual times I tested with 24 inserter threads Gordan> on a 24-thread server are 8m vs. 30m vs. 105m, i.e. Gordan> a massive drop. Why not use in memory tables for this? (ENGINE=MEMORY) Gordan> Is there an better place than this list for a Gordan> feature request? No, this is the right place. Regards, Monty _______________________________________________ Mailing list: https://launchpad.net/~maria-developers Post to : [email protected] Unsubscribe : https://launchpad.net/~maria-developers More help : https://help.launchpad.net/ListHelp
