[Maria-developers] Questions regarding closing partitions in MDEV-11084
Hi MariaDB Devs, I tried to evaluate spider engine and found an issue where it crashes, most likely due to MDEV-11084 (Stacktrace and reproducible test case attached). That also leads me to wonder about the performance for partitioned tables after MDEV-11084, when it seems to close partitions whenever it is not used in a statement (i.e. require it to be reopened in the next statement that would use another partition, effectively not using the open table cache). I cannot see anything mentioned in the final commit message hinting on that it closes partitions not used in the current query, but in the previous patches it was mentioned without any reason. Why does it close the already opened partitions? https://github.com/MariaDB/server/blob/10.3/sql/ha_partition.cc#L8365 I would not mind opening the partitions only when they are to be used (even though there are engines that need to be tested more), but closing them makes no sense to me performance wise. Also notice that the partitions first will be put back into the open table cache and then on the next query the non-used partitions will be closed and the needed ones be (re)-opened. Regards Mattias Jonsson
participants (1)
-
Mattias Jonsson