compare_keys_but_name(): do not use KEY_PART_INFO::field for
Field::is_equal(). Following the logic of that code we need to
compare fields of a table. But KEY_PART_INFO::field sometimes
(when key part is shorter than table field) is a different field.
In that case Field::is_equal() returns incorrect result and
problems occur.
KEY_PART_INFO::field may become some strange field in
open_frm_error open_table_from_share(). I think this is an
incorrect logic, some tecnhical debt. I'm not fixing it right now,
because I don't have time. But I'm making Field::field_length
a const class member. Then, the only fishy code which changed that
field requires now a const_cast<>. I'm bringing attention to that
code with it. This change should not affect logic of the
program in any way.
"write set" for replication finally got its correct place
(mark_columns_per_binlog_row_image()). When done generally in
mark_columns_needed_for_update() it affects optimization
algorithm. used_key_is_modified, query_plan.using_io_buffer are
wrongly set and that leads to wrong prepare_for_keyread() which limits
read_set.
Turn read cache off for update and multi-update for versioned
table. no_cache is reinited on each TABLE open because it is
applicable for specific algorithms.
As a side fix vers_insert_history_row() honors vers_write setting.
Aria with row_format=fixed uses IO_CACHE of type READ_CACHE for
sequential read in update loop. When history row is inserted inside
this loop the cache misses it and fails with error.
TODO:
Currently maria_extra() does not support SEQ_READ_APPEND. Probably it
might be possible to use this type of cache.
MDEV-18957 UPDATE with LIMIT clause is wrong for versioned partitioned tables
UPDATE, DELETE: replace linear search of current/historical records
with vers_setup_conds().
Additional DML cases in view.test
The issue here is the wrong estimate of the cardinality of a partial join,
the cardinality is too high because the function table_cond_selectivity()
returns an absurd number 100 while selectivity cannot be greater than 1.
When accessing table t by outer reference t1.a via index we do not perform any
range analysis for t. Yet we see TABLE::quick_key_parts[key] and
TABLE->quick_rows[key] contain a non-zero value though these should have been
remained untouched and equal to 0.
Thus real cause of the problem is that TABLE::init does not clean the arrays
TABLE::quick_key_parts[] and TABLE::>quick_rows[].
It should have done it because the TABLE structure created for any
instance of a table can be reused for many queries.
- Any temporary tables created under read-only mode will never be logged
to binary log. Any usage of these tables to update normal tables, even
after read-only has been disabled, will use row base logging (as the
temporary table will not be on the slave).
- Analyze, check and repair table will not be logged in read-only mode.
Other things:
- Removed not used varaibles in
MYSQL_BIN_LOG::flush_and_set_pending_rows_event.
- Set table_share->table_creation_was_logged for all normal tables.
- THD::binlog_query() now returns -1 if statement was not logged., This
is used to update table_share->table_creation_was_logged.
- Don't log admin statements in opt_readonly is set.
- Table's that doesn't have table_creation_was_logged will set binlog format to row
logging.
- Removed not needed/wrong setting of table->s->table_creation_was_logged
in create_table_from_items()
TABLE::mark_columns_needed_for_update(): use_all_columns() assigns
pointer of all_set into read_set and write_set, but this is not good
since all_set is changed later by
TABLE::mark_columns_used_by_index_no_reset().
Do column_bitmaps_signal() whenever we change read_set/write_set.
1. Removed TIMESTAMP/TRANSACTION unit auto-detection in favor of default TIMESTAMP.
Reasons:
1.1. rare practical use and doubtful advantage of such auto-detection;
1.2. it conflicts with MDEV-16226 (TRX_ID-based versioned tables performance improvement).
Needless check_unit membership removed.
2. SQL: versioning type handling refactoring
Vers_type_handler hierarchy stores versioning properties of type.
virtual Type_handler::vers() accesses specialization of
Vers_type_handler for specific type.
virtual Vers_type_handler::kind() returns versioning kind
(timestamp/trx_id).
Removed Type_handler::Vers_history_point_check_unit() in favor of
Type_handler::vers().
Renames:
require_timestamp() -> require_timestamp_error()
require_trx_id() -> require_trx_id_error()
EDIT by Alexander Barkov (@abarkov):
check_sys_fields() moved to Vers_type_handler::check_sys_fields()
This reverts commit 5a9e2b77d4 in 10.5,
so it produces an error on "bad" generated columns.
Note, 10.2, 10.3, 10.4 produce only warnings, for backward compatibility.
* remove one level of virtual functions
* remove redundant checks
* remove an if() as the value is always known at compilation time
don't pretend that "DEFAULT expr" and "ON UPDATE DEFAULT NOW"
are "basically the same thing"
