btr_pcur_store_position(): Assert that the 'default row' record never
is the only record in a page. (If that would happen, an empty
root page would be re-created in the non-instant format, not containing
the special record.) When the cursor is positioned on the page infimum,
never use the 'default row' as the BTR_PCUR_BEFORE reference.
(This is additional cleanup, not fixing the bug.)
rec_copy_prefix_to_buf(): When converting a record prefix to
the non-instant-add format, copy the original number of null flags.
Rename the variable instant_len to instant_omit, and introduce a
few more variables to make the code easiser to read.
Note: In purge, rec_copy_prefix_to_buf() is also used for storing the
persistent cursor position on a 'default row' record. The stored record
reference will be garbage, but row_search_on_row_ref() will do special
handling to reposition the cursor on the 'default row', based on
ref->info_bits.
innodb.dml_purge: Also cover the 'default row'.
The rollback of the modification of a pre-existing record
should involve a purge-like operation. Before MDEV-12288
the only purge-like operation was the removal of a
delete-marked record.
After MDEV-12288, any rollback of updating an existing record
must reset the DB_TRX_ID column when it is no longer visible
in the purge read view.
row_vers_must_preserve_del_marked(): Remove. It is cleaner to
perform the check directly in row0umod.cc.
row_trx_id_offset(): Auxiliary function to retrieve the byte
offset of DB_TRX_ID in a clustered index leaf page record.
row_undo_mod_must_purge(): Determine if a record should be purged.
row_undo_mod_clust(): For temporary tables, skip the purge checks.
When rolling back an update so that the original record was not
delete-marked, reset DB_TRX_ID if the history is no longer visible.
srv_purge_should_exit(): Remove the parameter n_purged.
If we happened to have n_purged==0 while some transaction was still
active, and then that transaction was added to the history list,
we were prematurely stopping the purge. It is more appropriate to
first check for trx_sys.any_active_transactions() == 0
(this count can only decrease during shutdown) and then for
trx_sys.history_size() == 0 (that count typically decreases, but
can increase when any remaining active transactions are committed
or rolled back).
innodb.dml_purge: Remove a server restart, and explicitly wait for
purge, and use FLUSH TABLE FOR EXPORT to read the file contents.
This will make the test run faster, easier to debug, and also
allow it to run with --embedded. This might also help repeat
MDEV-11802 better. The issue MDEV-13603 remains will remain tested
by innodb.table_flags.
In the test, SET GLOBAL innodb_purge_rseg_truncate_frequency = 1
in order to ensure that everything is purged in the slow shutdown.
This could be viewed as a flaw of the slow shutdown.
This should have been part of MDEV-12288.
trx_undo_t::del_marks: Remove.
Purge needs to process all undo log records in order to
reset the DB_TRX_ID. Before MDEV-12288, it sufficed to only delete
the purgeable delete-marked records, and it ignore other undo log.
trx_rseg_t::needs_purge: Renamed from trx_rseg_t::last_del_marks.
Indicates whether a rollback segment needs to be processed by purge.
TRX_UNDO_NEEDS_PURGE: Renamed from TRX_UNDO_DEL_MARKS.
Indicates whether a rollback segment needs to be processed by purge.
This will be 1 until trx_purge_free_segment() has been invoked.
row_purge_record_func(): Set the is_insert flag for TRX_UNDO_INSERT_REC,
so that the DB_ROLL_PTR will match in row_purge_reset_trx_id().
trx_purge_fetch_next_rec(): Add a comment about row_purge_record_func()
going to set the is_insert flag.
trx_purge_read_undo_rec(): Always attempt to read the undo log record.
trx_purge_get_next_rec(): Do not skip any undo log records.
Even when no clustered index record is going to be removed,
we may want to reset some DB_TRX_ID,DB_ROLL_PTR.
trx_undo_rec_get_cmpl_info(), trx_undo_rec_get_extern_storage(): Remove.
trx_purge_add_undo_to_history(): Set the TRX_UNDO_NEEDS_PURGE flag
so that the resetting will work on undo logs that were originally
created before MDEV-12288 (MariaDB 10.3.1).
trx_undo_roll_ptr_is_insert(), trx_purge_free_segment(): Cleanup
(should be no functional change).
