Treat queries with no FROM and aggregate functions as normal queries,
so the aggregate function get correctly calculated as if there is 1 row.
This means that they will be considered to have one row, so COUNT(*) will return
1 instead of 0. Other aggregates will behave in compatible manner.
The bug report revealed two problems related to min/max optimization:
1. If the length of a constant key used in a SARGable condition for
for the MIN/MAX fields is greater than the length of the field an
unwanted warning on key truncation is issued;
2. If MIN/MAX optimization is applied to a partial index, like INDEX(b(4))
than can lead to returning a wrong result set.
The problem was in that the MIN/MAX optimization in opt_sum_query was
replacing MIN/MAX functions with their constant argument without
taking into account that a query has no result rows.
Logging to logging@openlogging.org accepted
func_group.result, func_group.test:
Added a test case for bug #8893.
opt_sum.cc:
A misplaced initialization for the returned parameter
prefix_len in the function find_key_for_maxmin caused
usage of a wrong key prefix by the min/max optimization
in cases when the matching index was not the first index
that contained the min/max field.
New mysqltest that can run mysqltest with PS
Added support for ZEROFILL in PS
Fixed crash when one called mysql_stmt_store_result() without a preceding mysql_stmt_bind_result()
Updated test cases to support --ps-protocol
(Some tests are still run using old protocol)
Fixed crash in PS when using SELECT * FROM t1 NATURAL JOIN t2...
Fixed crash in PS when using sub queries
Create table didn't signal when table was created. This could cause a "DROP TABLE created_table" in another thread to wait "forever"
Fixed wrong permissions check in PS and multi-table updates (one could get permission denied for legal quries)
Fix for PS and SELECT ... PROCEDURE
Reset all warnings when executing a new PS query
group_concat(...ORDER BY) didn't work with PS
Fixed problem with test suite when not using innodb
Fixed bugs in group_concat with ORDER BY and DISTINCT (Bugs #2695, #3381 and #3319)
Fixed crash when doing rollback in slave and the io thread catched up with the sql thread
Set locked_in_memory properly
SQL_BIG_RESULT used": now BIT_AND() always returns 18446744073709551615
if no rows were found.
This patch also fixes bug #1972: "BIT_AND() and BIT_OR() still return
a *signed* 64bit value"
by MAX/MIN in some cases:
SELECT coercibility(max(s1)) from t1;
Subselect collation and derivation was not processed
correctly:
create table a select (select s1 from t1);
select * from t1 where s1 = (select s2 from t1);
Added new tests for better coverage of
min/max optimization code.
func_group.test:
Added new tests for better coverage of
min/max optimization code.
opt_sum.cc:
Fixed wrong previous manual merge.
Fixed bugs concerning fields used in min/max
functions for which there are conditions of
the form field=const.
Added ALL as parameter option for all group functions.
Make join handling uniform. This allows us to use ',', JOIN and INNER JOIN the same way.
Sort NULL last if DESC is used (ANSI SQL 99 requirement)
MIN(key_column) could in some cases return NULL on a column with NULL and other values.
MIN(key_column) and MAX(key_column) could in some cases return wrong values when used in OUTER JOIN.
