of the 5.3 code line after a merge with 5.2 on 2010-10-28
in order not to allow the cost to access a joined table to be equal
to 0 ever.
Expanded data sets for many test cases to get the same execution plans
as before.
- Set the default
- Adjust the testcases so that 'new' tests are run with optimizations turned on.
- Pull out relevant tests from "irrelevant" tests and run them with optimizations on.
- Run range.test and innodb.test with both mrr=on and mrr=off
- Make DsMrr_impl::dsmrr_init() handle the case of
1. 1st MRR scan using DS-MRR strategy (i.e. doing key sorting and rowid sorting)
2. 2nd MRR scan getting a buffer that's too small to fit one key element
and one rowid element, and so falling back to default MRR implementation
In this case, dsmrr_init() is invoked with {primary_handler, secondary_handler}
initialized for DS-MRR scan and have to reset them to be initialized for the
default MRR scan.
(attempt 2, with simplified testcase)
