Non-transactional updates that take place inside a transaction present problems
for logging because they are visible to other clients before the transaction
is committed, and they are not rolled back even if the transaction is rolled
back. It is not always possible to log correctly in statement format when both
transactional and non-transactional tables are used in the same transaction.
In the current patch, we ensure that such scenario is completely safe under the
ROW and MIXED modes.
The Blackhole engine did not support row-based replication
since the delete_row(), update_row(), and the index and range
searching functions were not implemented.
This patch adds row-based replication support for the
Blackhole engine by implementing the two functions mentioned
above, and making the engine pretend that it has found the
correct row to delete or update when executed from the slave
SQL thread by implementing index and range searching functions.
It is necessary to only pretend this for the SQL thread, since
a SELECT executed on the Blackhole engine will otherwise never
return EOF, causing a livelock.
mysql-test/extra/binlog_tests/blackhole.test:
Blackhole now handles row-based replication.
mysql-test/extra/rpl_tests/rpl_blackhole.test:
Test helper file for testing that blackhole actually
writes something to the binary log on the slave.
mysql-test/suite/binlog/t/binlog_multi_engine.test:
Replication now handles row-based replcation.
mysql-test/suite/rpl/t/rpl_blackhole.test:
Test that Blackhole works with primary key, index, or none.
sql/log_event.cc:
Correcting code to only touch filler bits and leave
all other bits alone. It is necessary since there is
no guarantee that the engine will be able to fill in
the bits correctly (e.g., the blackhole engine).
storage/blackhole/ha_blackhole.cc:
Adding definitions for update_row() and delete_row() to return OK
when executed from the slave SQL thread with thd->query == NULL
(indicating that row-based replication events are being processed).
Changing rnd_next(), index_read(), index_read_idx(), and
index_read_last() to return OK when executed from the slave SQL
thread (faking that the row has been found so that processing
proceeds to update/delete the row).
storage/blackhole/ha_blackhole.h:
Enabling row capabilities for engine.
Defining write_row(), update_row(), and delete_row().
Making write_row() private (as it should be).
