Active transactions must not switch table or index definitions on the fly,
for several reasons, including the following:
* copied indexes do not carry any history or locking information;
that is, rollbacks, read views, and record locking would be broken
* huge potential for race conditions, inconsistent reads and writes,
loss of data, and corruption
Instead of trying to track down if the table was changed during a transaction,
acquire appropriate locks that protect the creation and dropping of indexes.
innodb-index.test: Test the locking of CREATE INDEX and DROP INDEX. Test
that consistent reads work across dropped indexes.
lock_rec_insert_check_and_lock(): Relax the lock_table_has() assertion.
When inserting a record into an index, the table must be at least IX-locked.
However, when an index is being created, an IS-lock on the table is
sufficient.
row_merge_lock_table(): Add the parameter enum lock_mode mode, which must
be LOCK_X or LOCK_S.
row_merge_drop_table(): Assert that n_mysql_handles_opened == 0.
Unconditionally drop the table.
ha_innobase::add_index(): Acquire an X or S lock on the table, as appropriate.
After acquiring an X lock, assert that n_mysql_handles_opened == 1.
Remove the comments about dropping tables in the background.
ha_innobase::final_drop_index(): Acquire an X lock on the table.
dict_table_t: Remove version_number, to_be_dropped, and prebuilts.
ins_node_t: Remove table_version_number.
enum lock_mode: Move the definition from lock0lock.h to lock0types.h.
ROW_PREBUILT_OBSOLETE, row_update_prebuilt(), row_prebuilt_table_obsolete():
Remove.
row_prebuilt_t: Remove the declaration from row0types.h.
row_drop_table_for_mysql_no_commit(): Always print a warning if a table
was added to the background drop queue.
is inline and accesses lock_t members.
As advised by Marko rename lock_get_type() to lock_get_type_low() and
create a public non-inline function lock_get_type() which calls
lock_get_type_low().
Approved by: Marko
Move lock_rec_find_set_bit() from lock0priv.h to lock0lock.h. This
function is needed in the INFORMATION_SCHEMA implementation which
currently resides in trx/
Approved by: Marko
Replace all page_t* parameters with buf_block_t*, and replace many
rec_t* parameters with heap_no. This eliminates also many
rec_get_heap_no() calls, which became more expensive with the
introduction of ROW_FORMAT=COMPACT in MySQL/InnoDB 5.0.3.
page_rec_get_heap_no(), lock_get_min_heap_no(): New functions.
