Some trivial optimzations

Check if AND/OR expression can be NULL; Fixed bug in GROUP BY and-or-expression where expression could be NULL
Bug fix for SHOW OPEN TABLES when user didn't have privilege to access all open tables.
Better fix for ALTER TABLE on BDB tables.


Docs/manual.texi:
  Changelog
client/mysql.cc:
  Simple optimization
libmysql/libmysql.c:
  Removed initialization of varibles that are already set to zero
myisam/myisamchk.c:
  Fixed comment for extend-check
mysql-test/r/bdb-alter-table-1.result:
  Updated results
mysql-test/r/bdb-alter-table-2.result:
  Updated results
mysql-test/r/distinct.result:
  Updated results after bug fix
mysql-test/r/handler.result:
  Updated results
mysql-test/r/innodb_handler.result:
  Updated results
mysql-test/r/select.result:
  Updated results
mysql-test/r/varbinary.result:
  Updated results
mysql-test/t/bdb-alter-table-1.test:
  Added comments
mysql-test/t/bdb-alter-table-2.test:
  Added comments
mysql-test/t/select.test:
  Remove OPTION in SET OPTION
  Added tests for ORDER BY key LIMIT
sql/item_cmpfunc.cc:
  Check if AND/OR expression can be NULL
sql/mysqld.cc:
  mysqld --help now shows value of datadir
sql/share/english/errmsg.txt:
  Better error message for syntax error
sql/sql_base.cc:
  Bug fix for SHOW OPEN TABLES
sql/sql_class.cc:
  Moved virtual function to .cc file to avoid that we have to include assert.h everywhere.
sql/sql_class.h:
  Moved virtual function to .cc file to avoid that we have to include assert.h everywhere.
sql/sql_parse.cc:
  Removed old dead code from 3.23
sql/sql_select.cc:
  Improved optimization of ORDER BY key LIMIT
sql/sql_table.cc:
  More comments,
  Better fix for ALTER TABLE on BDB tables.

1 files changed, 16 insertions, 4 deletions

diff --git a/mysql-test/r/select.result b/mysql-test/r/select.result
index 26c84af1618..88220b75591 100644
--- a/mysql-test/r/select.result
+++ b/mysql-test/r/select.result
@@ -1718,7 +1718,7 @@ insert into tmp select * from t3;
 insert into t3 select * from tmp;
 alter table t3 add t2nr int not null auto_increment primary key first;
 drop table tmp;
-SET OPTION SQL_BIG_TABLES=1;
+SET SQL_BIG_TABLES=1;
 select distinct concat(fld3," ",fld3) as namn from t2,t3 where t2.fld1=t3.t2nr order by namn limit 10;
 namn
 Abraham Abraham
@@ -1731,7 +1731,7 @@ ammonium ammonium
 analyzable analyzable
 animals animals
 animized animized
-SET OPTION SQL_BIG_TABLES=0;
+SET SQL_BIG_TABLES=0;
 select distinct concat(fld3," ",fld3) from t2,t3 where t2.fld1=t3.t2nr order by fld3 limit 10;
 concat(fld3," ",fld3)
 Abraham Abraham
@@ -1768,7 +1768,7 @@ attendants	1
 bedlam	1
 bedpost	1
 boasted	1
-SET OPTION SQL_BIG_TABLES=1;
+SET SQL_BIG_TABLES=1;
 select distinct fld3,count(*) from t2 group by companynr,fld3 limit 10;
 fld3	count(*)
 affixed	1
@@ -1781,7 +1781,7 @@ attendants	1
 bedlam	1
 bedpost	1
 boasted	1
-SET OPTION SQL_BIG_TABLES=0;
+SET SQL_BIG_TABLES=0;
 select distinct fld3,repeat("a",length(fld3)),count(*) from t2 group by companynr,fld3 limit 100,10;
 fld3	repeat("a",length(fld3))	count(*)
 circus	aaaaaa	1
@@ -1809,6 +1809,18 @@ explain select t3.t2nr,fld3 from t2,t3 where t2.companynr = 34 and t2.fld1=t3.t2
 table	type	possible_keys	key	key_len	ref	rows	Extra
 t2	ALL	fld1	NULL	NULL	NULL	1199	where used; Using temporary; Using filesort
 t3	eq_ref	PRIMARY	PRIMARY	4	t2.fld1	1	where used; Using index
+explain select * from t3 as t1,t3 where t1.period=t3.period order by t3.period;
+table	type	possible_keys	key	key_len	ref	rows	Extra
+t1	ALL	period	NULL	NULL	NULL	41810	Using temporary; Using filesort
+t3	ref	period	period	4	t1.period	4181	
+explain select * from t3 as t1,t3 where t1.period=t3.period order by t3.period limit 10;
+table	type	possible_keys	key	key_len	ref	rows	Extra
+t3	index	period	period	4	NULL	41810	
+t1	ref	period	period	4	t3.period	4181	
+explain select * from t3 as t1,t3 where t1.period=t3.period order by t1.period limit 10;
+table	type	possible_keys	key	key_len	ref	rows	Extra
+t1	index	period	period	4	NULL	41810	
+t3	ref	period	period	4	t1.period	4181	
 select period from t1;
 period
 9410