This essentially reverts commit 4e89ec6692
and only disables InnoDB persistent statistics for tests where it is
desirable. By design, InnoDB persistent statistics will not be updated
except by ANALYZE TABLE or by STATS_AUTO_RECALC.
The internal transactions that update persistent InnoDB statistics
in background tasks (with innodb_stats_auto_recalc=ON) may cause
nondeterministic query plans or interfere with some tests that deal
with other InnoDB internals, such as the purge of transaction history.
PARTITION clause in SELECT means query is non-versioned (see
WITH_PARTITION_STORAGE_ENGINE in vers_setup_conds()).
vers_setup_conds() expands such query to SYSTEM_TIME_ALL which is then
added to VIEW specification. When VIEW is queried both clauses
PARTITION and FOR SYSTEM_TIME ALL lead to ER_VERS_QUERY_IN_PARTITION
(same place WITH_PARTITION_STORAGE_ENGINE).
Fix removes FOR SYSTEM_TIME ALL from VIEW by accessing original
SYSTEM_TIME clause: the one specified in parser. As a side-effect
EXPLAIN SELECT displays SYSTEM_TIME specified in SELECT which is
user-friendly.
- multi_range_read_info_const now uses the new records_in_range interface
- Added handler::avg_io_cost()
- Don't calculate avg_io_cost() in get_sweep_read_cost if avg_io_cost is
not 1.0. In this case we trust the avg_io_cost() from the handler.
- Changed test_quick_select to use TIME_FOR_COMPARE instead of
TIME_FOR_COMPARE_IDX to align this with the rest of the code.
- Fixed bug when using test_if_cheaper_ordering where we didn't use
keyread if index was changed
- Fixed a bug where we didn't use index only read when using order-by-index
- Added keyread_time() to HEAP.
The default keyread_time() was optimized for blocks and not suitable for
HEAP. The effect was the HEAP prefered table scans over ranges for btree
indexes.
- Fixed get_sweep_read_cost() for HEAP tables
- Ensure that range and ref have same cost for simple ranges
Added a small cost (MULTI_RANGE_READ_SETUP_COST) to ranges to ensure
we favior ref for range for simple queries.
- Fixed that matching_candidates_in_table() uses same number of records
as the rest of the optimizer
- Added avg_io_cost() to JT_EQ_REF cost. This helps calculate the cost for
HEAP and temporary tables better. A few tests changed because of this.
- heap::read_time() and heap::keyread_time() adjusted to not add +1.
This was to ensure that handler::keyread_time() doesn't give
higher cost for heap tables than for normal tables. One effect of
this is that heap and derived tables stored in heap will prefer
key access as this is now regarded as cheap.
- Changed cost for index read in sql_select.cc to match
multi_range_read_info_const(). All index cost calculation is now
done trough one function.
- 'ref' will now use quick_cost for keys if it exists. This is done
so that for '=' ranges, 'ref' is prefered over 'range'.
- scan_time() now takes avg_io_costs() into account
- get_delayed_table_estimates() uses block_size and avg_io_cost()
- Removed default argument to test_if_order_by_key(); simplifies code
(Backported to 10.3, addressed review input)
Sj_materialization_picker::check_qep(): fix error in cost/fanout
calculations:
- for each join prefix, add #prefix_rows / TIME_FOR_COMPARE to the cost,
like best_extension_by_limited_search does
- Remove the fanout produced by the subquery tables.
- Also take into account join condition selectivity
optimize_wo_join_buffering() (used by LooseScan and FirstMatch)
- also add #prefix_rows / TIME_FOR_COMPARE to the cost of each prefix.
- Also take into account join condition selectivity
Make sure that SELECT_LEX_UNIT::derived, behaves as documented
(points to the "TABLE_LIST representing this union in the
embedding select"). For recursive CTE this was not necessarily
the case, it could've pointed to the TABLE_LIST inside the CTE,
not in the embedding select.
To fix:
* don't update unit->derived in mysql_derived_prepare(), pass derived
as an argument to st_select_lex_unit::prepare()
* prefer to set unit->derived in TABLE_LIST::init_derived()
to the TABLE_LIST in the embedding select, not to the recursive
reference. Fail if there are many TABLE_LISTs in the embedding
select with conflicting FOR SYSTEM_TIME clauses.
cleanup:
* remove redundant THD* argument from st_select_lex_unit::prepare()
non-standard, redundant, potentially risky in the future,
hides bugs. See #383, #384, #385
Fixed a parser bug where
SELECT * FROM (t1 join t2) FOR SYSTEM_TIME ...
was not an error.
* again, as in 10.2, NOW is a keyword only if followed by parentheses
* use AS OF CURRENT_TIMESTAMP or AS OF NOW()
* AS OF CURRENT_TIMESTAMP and AS OF NOW() mean AS OF NOW(6),
not AS OF NOW(0), (same behavior as in a DEFAULT clause)
