into  mysql.com:/home/kgeorge/mysql/5.0/warnings

into  mysql.com:/home/kgeorge/mysql/4.1/warnings

into  mysql.com:/home/kgeorge/mysql/4.1/B16458

into  mysql.com:/home/kgeorge/mysql/5.0/B16458

'SELECT DISTINCT a,b FROM t1' should not use temp table if there is unique 
index (or primary key) on a.
There are a number of other similar cases that can be calculated without the
use of a temp table : multi-part unique indexes, primary keys or using GROUP BY 
instead of DISTINCT.
When a GROUP BY/DISTINCT clause contains all key parts of a unique
index, then it is guaranteed that the fields of the clause will be
unique, therefore we can optimize away GROUP BY/DISTINCT altogether.
This optimization has two effects:
* there is no need to create a temporary table to compute the
   GROUP/DISTINCT operation (or the temporary table will be smaller if only GROUP 
   is removed and DISTINCT stays or if DISTINCT is removed and GROUP BY stays)
* this causes the statement in effect to become updatable in Connector/Java
because the result set columns will be direct reference to the primary key of 
the table (instead to the temporary table that it currently references). 

Implemented a check that will optimize away GROUP BY/DISTINCT for queries like 
the above.
Currently it will work only for single non-constant table in the FROM clause.

into  rurik.mysql.com:/home/igor/mysql-5.0-opt

This was another manifestation of the problems fixed in the
patch for bug 16674.
Wrong calculation of length of the search prefix in the pattern
string led here to a wrong result set for a query in 4.1. 
The bug could be demonstrated for any multi-byte character set. 

into  rurik.mysql.com:/home/igor/mysql-5.0-opt

Server crashed in some cases when a query required a MIN/MAX
agrregation for a 'ucs2' field. 
In these cases  the aggregation caused calls of the function
update_tmptable_sum_func that indirectly invoked 
the method Item_sum_hybrid::min_max_update_str_field() 
containing a call to strip_sp for a ucs2 character set.
The latter led directly to the crash as it used my_isspace
undefined for the ucs2 character set.
Actually the call of strip_sp is not needed at all in this
situation and has been removed by the fix.

into  rurik.mysql.com:/home/igor/mysql-5.0-opt

execution plans in 4.1 and 5.0.

into  rurik.mysql.com:/home/igor/mysql-5.0-opt

into  rurik.mysql.com:/home/igor/mysql-4.1-opt

into moonbone.local:/work/tmp_merge-5.0-opt-mysql

into moonbone.local:/work/tmp_merge-5.0-opt-mysql

into moonbone.local:/work/tmp_merge-4.1-opt-mysql

This bug in Field_string::cmp resulted in a wrong comparison 
with keys in partial indexes over multi-byte character fields.
Given field a is declared as a varchar(16) collate utf8_unicode_ci
INDEX(a(4)) gives us an example of such an index.
  
Wrong key comparisons could lead to wrong result sets if 
the selected query execution plan used a range scan by 
a partial index over a utf8 character field.
This also caused wrong results in many other cases.

into  mysql.com:/home/bk/fix-mysql-5.0

into  may.pils.ru:/home/svoj/devel/mysql/BUG20357/mysql-5.0

into  may.pils.ru:/home/svoj/devel/mysql/BUG20357/mysql-4.1

into  may.pils.ru:/home/svoj/devel/mysql/BUG20357/mysql-4.1

            functions in queries

Using MAX()/MIN() on table with disabled indexes (by ALTER TABLE)
results in error 124 (wrong index) from storage engine.

The problem was that optimizer use disabled index to optimize
MAX()/MIN(). Normally it must skip disabled index and perform
table scan.

This patch skips disabled indexes for min/max optimization.

into  mysql.com:/data0/knielsen/mysql-5.0

Backport Valgrind suppression from mysql-5.1:

D 1.4 05/11/23 22:44:54+02:00 monty@mysql.com 5 4 12/0/154
P mysql-test/valgrind.supp
C Remove warning that may happens becasue threads dies in different order

into  mysql.com:/home/kgeorge/mysql/5.0/B18080

into  mysql.com:/home/marty/MySQL/mysql-5.0

into  poseidon.ndb.mysql.com:/home/tomas/mysql-5.0-main

into  mysql.com:/home/kgeorge/mysql/5.0/B20482

            schemas
The function check_one_table_access() called to check access to tables in 
SELECT/INSERT/UPDATE was doing additional checks/modifications that don't hold
in the context of setup_tables_and_check_access().
That's why the check_one_table() was split into two : the functionality needed by
setup_tables_and_check_access() into check_single_table_access() and the rest of 
the functionality stays in check_one_table_access() that is made to call the new
check_single_table_access() function.

into  mysql.com:/home/marty/MySQL/mysql-5.0

into  poseidon.ndb.mysql.com:/home/tomas/mysql-5.0-main