The problem here is EITS statistics does not calculate statistics for the partitions of the table.
So a temporary solution would be to not read EITS statistics for partitioned tables.
Also disabling reading of EITS for columns that participate in the partition list of a table.
In this case we were trying to access memory for key_parts which we did not
assign for a fields because it did not any EITS statistics.
The check if EITS statistics for a column is avaialable or not was missing.
main.derived_cond_pushdown: Move all 10.3 tests to the end,
trim trailing white space, and add an "End of 10.3 tests" marker.
Add --sorted_result to tests where the ordering is not deterministic.
main.win_percentile: Add --sorted_result to tests where the
ordering is no longer deterministic.
For index merge union[or sort union], the estimates are not taken into account while calculating the selectivity of
a condition. So instead of showing the estimates of the index merge union[or sort union], it shows estimates equal to
all the records of the table.
The fix for the issue is to include the selectivity of index merge
union[or sort union] while calculating the selectivity of a condition.
optimizer_use_condition_selectivity>=3
Selectivity analysis should be disabled for Geometrical columns
for the case like geometric_field= string_constant.
Currently for selectivity calculation we perform range analysis for a column even when we don't have any statistics(EITS).
This makes less sense but is used to catch contradiction for WHERE condition.
So the solution is to not perform range analysis for selectivity calculation for columns that do not have statistics.
and use_stat_tables= PREFERABLY
Currently the code that calculates selectivity for a table does not take into account the case when
we can have GROUP BY optimization (looses index scan).
This patch introduces support for the system variable eq_range_index_dive_limit
that existed in MySQL starting from 5.6. The variable sets a limit for
index dives into equality ranges. Index dives are performed by optimizer
to estimate the number of rows in range scans. Index dives usually provide
good estimate but they are pretty expensive. To estimate the number of rows
in equality ranges statistical data on indexes can be employed. Its usage gives
not so good estimates but it's cheap. So if the number of equality dives
required by an index scan exceeds the set limit no dives for equality
ranges are performed by the optimizer for this index.
As the new system variable is introduced in a stable version the default
value for it is set to a special value meaning there is no limit for the number
of index dives performed by the optimizer.
The patch partially uses the MySQL code for WL 5957
'Statistics-based Range optimization for many ranges'.
Now the boolean data type is preserved in hybrid functions and MIN/MAX,
so COALESCE(bool_expr,bool_expr) and MAX(bool_expr) are correctly
detected by JSON_OBJECT() as being boolean rather than numeric expressions.
- Removing tests of item->type() against INT_ITEM and replacing
them to calls of new method item->is_bool_literal().
- Changing constant conditions to use Item_bool() instead of Item_int().
Lots of changes:
* calculate the current history partition in ::external_lock(),
not in ::write_row() or ::update_row()
* remove dynamically collected per-partition row_end stats
* no full table scan in open_table_from_share to calculate these
stats, no manual MDL/thr_locks in open_table_from_share
* no shared stats in TABLE_SHARE = no mutexes or condition waits when
calculating current history partition
* always compare timestamps, don't convert them to MYSQL_TIME
(avoid DST ambiguity, and it's faster too)
* correct interval handling, 1 month = 1 month, not 30 * 24 * 3600 seconds
* save/restore first partition start time, and count intervals from there
* only allow to drop first partitions if INTERVAL
* when adding new history partitions, split the data in the last history
parition, if it was overflowed
* show partition boundaries in INFORMATION_SCHEMA.PARTITIONS
There were two problems related to the bug report:
1. Item_datetime::get_date() was not implemented.
So execution went through val_int() followed
by int-to-datetime or int-to-time conversion.
This was the reason why the optimizer did not
work well on data with fractional seconds.
2. Item_datetime::set() did not have a TIME specific code
to mix months and days to hours after unpack_time().
This is why the optimizer did not work well with negative
TIME values, as well as huge time values.
Changes:
1. Overriding Item_datetime::get_date(), to return ltime.
This fixes the problem N1.
2. Cleanup: Moving pack_time() and unpack_time() from
sql-common/my_time.c and include/my_time.h to
sql/sql_time.cc and sql/sql_time.h, as they are not needed
on the client side.
3. Adding a new "enum_mysql_timestamp_type ts_type" parameter
to unpack_time() and moving the TIME specific code to mix
months and days with hours inside unpack_time().
Adding a new "ts_type" parameter to Item_datetime::set(),
to pass it from the caller down to unpack_time().
So now the TIME specific code is automatically called
from Item_datetime::set(). This fixes the problem N2.
This change also helped to get rid of duplicate TIME specific code
from other three places, where mixing month/days to hours
was done immediately after unpack_time().
Moving the DATE specific code to zero hhmmssff
from Item_func_min_max::get_date_native to inside unpack_time(),
for symmetry.
4. Removing the virtual method in_vector::result_type(),
adding in_vector::type_handler() instead.
This helps to get result_type(), field_type(),
mysql_timestamp_type() of an in_vector easier.
Passing type_handler()->mysql_timestamp_type() as
a new parameter to Item_datetime::set() inside
in_temporal::value_to_item().
5. Cleaup: Removing separate implementations of in_datetime::get_value()
and in_time::get_value(). Adding a single implementation
in_temporal::get_value() instead.
Passing type_handler()->field_type() to get_value_internal().
Handle string length as size_t, consistently (almost always:))
Change function prototypes to accept size_t, where in the past
ulong or uint were used. change local/member variables to size_t
when appropriate.
This fix excludes rocksdb, spider,spider, sphinx and connect for now.
