MWL#17: Table elimination

- Add more testcases.
- Fix trivial compile failure
- Remove handling of "column IN (one_element)". This is converted to equality 
  elsewhere

mysql-test/r/table_elim.result:
  MWL#17: Table elimination
  - Add more testcases.
  - Fix trivial compile failure
mysql-test/t/table_elim.test:
  MWL#17: Table elimination
  - Add more testcases
sql/mysqld.cc:
  MWL#17: Table elimination
  - Fix trivial compile failure
sql/opt_table_elimination.cc:
  MWL#17: Table elimination
  - Add more testcases.
  - Remove handling of "column IN (one_element)".This is converted to equality 
    elsewhere

mysql-test/r/table_elim.result

@@ -307,3 +307,41 @@ a	b
 select * from t2;
 a	b
 drop table t1, t2;
+#
+# Tests with various edge-case ON expressions
+#
+create table t1 (a int, b int, c int, d int);
+insert into t1 values (0,0,0,0),(1,1,1,1),(2,2,2,2),(3,3,3,3);
+create table t2 (pk int primary key, b int) 
+as select a as pk, a as b from t1 where a in (1,2);
+create table t3 (pk int primary key, b int) 
+as select a as pk, a as b from t1 where a in (1,3);
+explain select t1.a from t1 left join t2 on t2.pk=t1.a and t2.b<t1.b;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	4	
+explain select t1.a from t1 left join t2 on t2.pk=t1.a or t2.b<t1.b;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	4	
+1	SIMPLE	t2	ALL	PRIMARY	NULL	NULL	NULL	2	
+explain select t1.a from t1 left join t2 on t2.b<t1.b or t2.pk=t1.a;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	4	
+1	SIMPLE	t2	ALL	PRIMARY	NULL	NULL	NULL	2	
+explain select t1.a from t1 left join t2 on t2.pk between 10 and 20;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	4	
+1	SIMPLE	t2	index	PRIMARY	PRIMARY	4	NULL	2	Using index
+explain select t1.a from t1 left join t2 on t2.pk between 0.5 and 1.5;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	4	
+1	SIMPLE	t2	index	PRIMARY	PRIMARY	4	NULL	2	Using index
+explain select t1.a from t1 left join t2 on t2.pk between 10 and 10;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	4	
+explain select t1.a from t1 left join t2 on t2.pk in (10);
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	4	
+explain select t1.a from t1 left join t2 on t2.pk in (t1.a);
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	4	
+drop table t1,t2,t3;

mysql-test/t/table_elim.test

@@ -249,3 +249,30 @@ select * from t1;
 select * from t2;
 drop table t1, t2;
 
+--echo #
+--echo # Tests with various edge-case ON expressions
+--echo #
+create table t1 (a int, b int, c int, d int);
+insert into t1 values (0,0,0,0),(1,1,1,1),(2,2,2,2),(3,3,3,3);
+
+create table t2 (pk int primary key, b int) 
+  as select a as pk, a as b from t1 where a in (1,2);
+
+create table t3 (pk1 int, pk2 int, b int, unique(pk1,pk2));
+insert into t3 select a as pk1, a as pk2, a as b from t1 where a in (1,3);
+
+explain select t1.a from t1 left join t2 on t2.pk=t1.a and t2.b<t1.b;
+explain select t1.a from t1 left join t2 on t2.pk=t1.a or t2.b<t1.b;
+explain select t1.a from t1 left join t2 on t2.b<t1.b or t2.pk=t1.a;
+
+explain select t1.a from t1 left join t2 on t2.pk between 10 and 20;
+explain select t1.a from t1 left join t2 on t2.pk between 0.5 and 1.5;
+explain select t1.a from t1 left join t2 on t2.pk between 10 and 10;
+
+explain select t1.a from t1 left join t2 on t2.pk in (10);
+explain select t1.a from t1 left join t2 on t2.pk in (t1.a);
+
+explain select t1.a from t1 left join t2 on TRUE;
+
+drop table t1,t2,t3;
+

sql/mysqld.cc

@@ -393,6 +393,8 @@ static const char *optimizer_switch_str="index_merge=on,index_merge_union=on,"
                                         "index_merge_intersection=on"
 #ifndef DBUG_OFF                                        
                                         ",table_elimination=on";
+#else
+                                        ;
 #endif
 static char *mysqld_user, *mysqld_chroot, *log_error_file_ptr;
 static char *opt_init_slave, *language_ptr, *opt_init_connect;

sql/opt_table_elimination.cc

@@ -467,15 +467,6 @@ void build_eq_mods_for_cond(Func_dep_analyzer *fda, Equality_module **eq_mod,
   Item **args= cond_func->arguments();
 
   switch (cond_func->functype()) {
-  case Item_func::IN_FUNC:
-  {
-    if (cond_func->argument_count() == 2)
-    {
-      add_eq_mod(fda, eq_mod, *and_level, cond_func, args[0], args[1]);
-      add_eq_mod(fda, eq_mod, *and_level, cond_func, args[1], args[0]);
-    }
-    break;
-  }
   case Item_func::BETWEEN:
   {
     Item *fld;
@@ -837,7 +828,7 @@ static Table_value *get_table_value(Func_dep_analyzer *fda, TABLE *table)
 {
   Table_value *tbl_dep;
   if (!(tbl_dep= new Table_value(table)))
-    return NULL;
+    return NULL; /* purecov: inspected */
 
   Key_module **key_list= &(tbl_dep->keys);
   /* Add dependencies for unique keys */
@@ -1499,6 +1490,7 @@ static void mark_as_eliminated(JOIN *join, TABLE_LIST *tbl)
 
 
 #ifndef DBUG_OFF
+/* purecov: begin inspected */
 static 
 void dbug_print_deps(Func_dep_analyzer *fda)
 {
@@ -1559,6 +1551,7 @@ void dbug_print_deps(Func_dep_analyzer *fda)
   DBUG_UNLOCK_FILE;
   DBUG_VOID_RETURN;
 }
+/* purecov: end */
 
 #endif 
 /**