The optimizer takes different execution paths during EXPLAIN than SELECT,
this fix relates only to EXPLAIN, hence no behavior changes.
The test of sort keys for ORDER BY was prohibited from considering keys
that were mentioned in IGNORE KEYS FOR ORDER BY. This led to two
inconsistencies: One was that IGNORE INDEX FOR GROUP BY and
IGNORE INDEX FOR ORDER BY gave apparently different EXPLAINs; the latter
erroneously claimed to do filesort. The second inconsistency
is that the test of sort keys is called twice, finding a sort key the first
time but not the second time, leading to the mentioned filesort.
Fixed by making the test of sort keys consider all enabled
keys on the table. This test rejects keys that are not covering, and for
covering keys the hint should be ignored anyway.
When expanding a * in a USING/NATURAL join the check for table access
for both tables in the join was done using the grant information of the
first one.
Fixed by getting the grant information for the current table while
iterating through the columns of the join.
The `SELECT col FROM t WHERE col NOT IN (col, ...) GROUP BY col'
crashed in the range optimizer.
The get_func_mm_tree function has been modified to check the
Item_func_in::array field for the NULL value before using of that
value.
When storing the VIEW the CREATE VIEW command is reconstructed
from the parse tree. While constructing the command string
the index hints specified should also be printed.
Fixed by adding code to print the index hints when printing a
table in the FROM clause.
type of the result.
There are several functions that accept parameters of different types.
The result field type of such functions was determined based on
the aggregated result type of its arguments. As the DATE and the DATETIME
types are represented by the STRING type, the result field type
of the affected functions was always STRING for DATE/DATETIME arguments.
The affected functions are COALESCE, IF, IFNULL, CASE, LEAST/GREATEST, CASE.
Now the affected functions aggregate the field types of their arguments rather
than their result types and return the result of aggregation as their result
field type.
The cached_field_type member variable is added to the number of classes to
hold the aggregated result field type.
The str_to_date() function's result field type now defaults to the
MYSQL_TYPE_DATETIME.
The agg_field_type() function is added. It aggregates field types with help
of the Field::field_type_merge() function.
The create_table_from_items() function now uses the
item->tmp_table_field_from_field_type() function to get the proper field
when the item is a function with a STRING result type.
led to creating corrupted index.
While execution of the CREATE .. SELECT SQL_BUFFER_RESULT statement the
engine->start_bulk_insert function was called twice. On the first call
On the first call MyISAM disabled all non-unique indexes and on the second
call it decides to not re-enable them because all indexes was disabled.
Due to this no indexes was actually created during CREATE TABLE thus
producing crashed table.
Now the select_inset class has is_bulk_insert_mode flag which prevents
calling the start_bulk_insert function twice.
The flag is set in the select_create::prepare, select_insert::prepare2
functions and the select_insert class constructor.
The flag is reset in the select_insert::send_eof function.
added get_field_default_value() function which obtains default value from the field
(used in store_create_info() & get_schema_column_record() functions)
The parser uses ulonglong to store the LIMIT number. This number
then is stored into a variable of type ha_rows. ha_rows is either
4 or 8 byte depending on the BIG_TABLES define from config.h
So an overflow may occur (and LIMIT becomes zero) while storing an
ulonglong value in ha_rows.
Fixed by :
1. Using the maximum possible value for ha_rows on overflow
2. Defining BIG_TABLES for the windows builds (to match the others)
Multiple-result processing is required during the execution
of CALL statements for stored procedures, however the mysqlslap
client lacked that processing.
The optimizer sets index traversal in reverse order only if there are
used key parts that are not compared to a constant.
However using the primary key as an ORDER BY suffix rendered the check
incomplete : going in reverse order must still be used even if
all the parts of the secondary key are compared to a constant.
Fixed by relaxing the check and set reverse traversal even when all
the secondary index keyparts are compared to a const.
Also account for the case when all the primary keys are compared to a
constant.
- The bug was caused by COUNT(DISTINCT ...) code using Unique object in
a way that assumed that BIT(N) column occupies a contiguous space in
temp_table->record[0] buffer.
- The fix is to make COUNT(DISTINCT ...) code instruct create_tmp_table to
create temporary table with column of type BIGINT, not BIT(N).
