opt_calc_index_goodness(): Correct an inaccurate condition.
We can very well use a clustered index of a table that is subject
to online rebuild. But we must not choose an index that has not been
committed (it is a secondary index that was not fully created)
or that is corrupted or not a normal B-tree index.
opt_search_plan_for_table(): Remove some redundant code, now that
opt_calc_index_goodness() checks against corrupted indexes.
The test case allows this code to be exercised. The main observation
in the following:
./mtr --rr innodb.stats_persistent
rr replay var/log/mysqld.1.rr/latest-trace
should be that when opt_search_plan_for_table() is being invoked by
dict_stats_update_persistent() on the being-altered statistics table
in the 2nd call after ha_innobase::inplace_alter_table(),
and the fix in opt_calc_index_goodness() is absent,
it would choose the code path if (n_fields == 0), that is, a full
table scan, instead of searching for the record. The GDB commands to
execute in "rr replay" would be as follows:
break ha_innobase::inplace_alter_table
continue
break opt_search_plan_for_table
continue
continue
next
next
…
Reviewed by: Vladislav Lesin
e5c4c0842d