I think we found out the problem. In ha_partition.cc, in the function ha_partition::handle_ordered_index_scan, this code was added: case partition_index_last: /* MyISAM engine can fail if we call index_last() when indexes disabled that happens if the table is empty. Here we use file->stats.records instead of file->records() because file->records() is supposed to return an EXACT count, and it can be possibly slow. We don't need an exact number, an approximate one- from the last ::info() call - is sufficient. */ if (file->stats.records == 0) { error= HA_ERR_END_OF_FILE; break;
We always thought that stats.records was meant to be an estimate, and that an estimate of 0 was ok even if the table was non-empty. We were reporting that stats.records was 0 even though the table was non-empty. Is this assumption wrong? -Zardosht On Wed, Dec 8, 2010 at 2:42 PM, Kristian Nielsen <kniel...@knielsen-hq.org> wrote: > Zardosht Kasheff <zardo...@gmail.com> writes: > >> We have been working on testing our storage engine, TokuDB, against >> MariaDB 5.2.3, and we have encountered a problem with partitioning >> that does not exist on MySQL 5.1, MySQL 5.5, and MariaDB 5.1.50. This >> problem also does not exist with any other storage engine that we have >> tried. It ONLY exists with TokuDB and MariaDB 5.2. > >> Here is what the test is doing: >> >> 1. Create a table with some partitions >> 2. update the table >> 3. run select max(f_int1) >> 4. run select * >> 5. run select max(f_int1) again. >> >> The problem is that the query results for 3 are incorrect, even though >> the query results for 4 and 5 are correct. MySQL 5.1, MySQL 5.5, and >> MariaDB 5.1 produce the correct results for 3. >> >> What makes this even stranger is that the query results for 4 and 5 >> are always correct. > > It's hard to say without any code. Can you post link to launchpad tree or > source tarball with which to reproduce? > > From the information given, I would suggest to run the test with --valgrind, > in case the problem is some uninitialised memory being referenced; sometimes > Valgrind can help catch this. > > - Kristian. > _______________________________________________ Mailing list: https://launchpad.net/~maria-developers Post to : maria-developers@lists.launchpad.net Unsubscribe : https://launchpad.net/~maria-developers More help : https://help.launchpad.net/ListHelp