on any access
Archive engine for 5.1 (and latter) version uses a modified
version of zlib (azlib). These two version are incompatible
so a proper upgrade is needed before tables created in 5.0
can be used reliable.
This upgrade can be performed using repair. But due to lack
of test its risky to allow upgrade for now. This patch addresses
only the crashing issue. Any attempt to repair will be blocked.
Eventually repair can be allowed to run through (which will also
cause an upgrade from older version to newer) but only after a
thorough testing.
The additional patch. That 'loadxml.test' failure was actually about our testing system,
not the code.
Firstly we need a new mysqltest command, wich i called 'send_eval'. So the expression
can be evaluated, then started in a parallel thread. We only have separane 'send' and
'eval' commands at the moment.
Then we need to add the waiting code after the 'KILL' to our test, so the thread will be killed
before the test goes further. The present 'reap' command doesn't handle the killed threads
well.
per-file comments:
client/mysqltest.cc
Bug#42520 killing load .. infile Assertion failed: ! is_set(), file .\sql_error.cc, line 8
The 'send_eval' command implemented.
mysql-test/r/loadxml.result
Bug#42520 killing load .. infile Assertion failed: ! is_set(), file .\sql_error.cc, line 8
test result updated.
mysql-test/t/loadxml.test
Bug#42520 killing load .. infile Assertion failed: ! is_set(), file .\sql_error.cc, line 8
test case added.
memory
The server was doing a bad class typecast causing setting of
wrong value for the maximum number of items in an internal
structure used in equality propagation.
Fixed by not doing the wrong typecast and asserting the type
of the Item where it should be done.
values
We should re-set the access method functions when changing the access
method when switching to another index to avoid sorting.
Fixed by doing a little re-engineering : encapsulating all the function
assignment into a special function and calling it when flipping the
indexes.
only const tables
The problem was caused by two shortcuts in the optimizer that
are inapplicable in the ROLLUP case.
Normally in a case when only const tables are involved in a
query, DISTINCT clause can be safely optimized away since there
may be only one row produced by the join. Similarly, we don't
need to create a temporary table to resolve DISTINCT/GROUP
BY/ORDER BY. Both of these are inapplicable when the WITH
ROLLUP modifier is present.
Fixed by disabling the said optimizations for the WITH ROLLUP
case.
Some output is written, some is not
Finally concluded it's a Perl bug: after running with parallel threads
for a while, print suddenly ignores all but the first argument.
Workaround: concatenate all the arguments into one, except in output that
only comes before we start running tests
The SE API requires mysql to notify the storage engine that
it's going to read certain tables at the beginning of the
statement (by calling start_stmt(), store_lock() or
external_lock()).
These are typically called by the lock_tables().
However SHOW CREATE TABLE is not pre-locking the tables
because it's not expected to access the data at all.
But for some view definitions (that include comparing a
date/datetime/timestamp column to a string returning
scalar subquery) the JOIN::prepare may still access data
when materializing the scalar non-correlated subquery
in Arg_comparator::can_compare_as_dates().
Fixed by not materializing the subquery when the function
is called in a SHOW/EXPLAIN/CREATE VIEW
