MWL#90, code cleanup

- Remove garbage comments
- fix a bug in join_tab_cmp

mysql-test/r/subselect3.result

@@ -1398,7 +1398,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 2	SUBQUERY	cona	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where
 2	SUBQUERY	c	eq_ref	PRIMARY	PRIMARY	4	test.cona.idContact	1	100.00	
 Warnings:
-Note	1003	select `test`.`a`.`idIndividual` AS `idIndividual` from `test`.`t1` `a` semi join (`test`.`t3` `cona` join `test`.`t2` `c`) where ((`test`.`cona`.`idContact` = `test`.`c`.`idContact`) and (`test`.`a`.`idIndividual` = `test`.`c`.`idObj`) and (`test`.`cona`.`postalStripped` = 'T2H3B2'))
+Note	1003	select `test`.`a`.`idIndividual` AS `idIndividual` from `test`.`t1` `a` semi join (`test`.`t3` `cona` join `test`.`t2` `c`) where ((`test`.`c`.`idContact` = `test`.`cona`.`idContact`) and (`test`.`a`.`idIndividual` = `test`.`c`.`idObj`) and (`test`.`cona`.`postalStripped` = 'T2H3B2'))
 drop table t1,t2,t3;
 #
 # BUG#47367 Crash in Name_resolution_context::process_error

mysql-test/r/subselect3_jcl6.result

@@ -1402,7 +1402,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 2	SUBQUERY	cona	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where
 2	SUBQUERY	c	eq_ref	PRIMARY	PRIMARY	4	test.cona.idContact	1	100.00	Using join buffer
 Warnings:
-Note	1003	select `test`.`a`.`idIndividual` AS `idIndividual` from `test`.`t1` `a` semi join (`test`.`t3` `cona` join `test`.`t2` `c`) where ((`test`.`cona`.`idContact` = `test`.`c`.`idContact`) and (`test`.`a`.`idIndividual` = `test`.`c`.`idObj`) and (`test`.`cona`.`postalStripped` = 'T2H3B2'))
+Note	1003	select `test`.`a`.`idIndividual` AS `idIndividual` from `test`.`t1` `a` semi join (`test`.`t3` `cona` join `test`.`t2` `c`) where ((`test`.`c`.`idContact` = `test`.`cona`.`idContact`) and (`test`.`a`.`idIndividual` = `test`.`c`.`idObj`) and (`test`.`cona`.`postalStripped` = 'T2H3B2'))
 drop table t1,t2,t3;
 #
 # BUG#47367 Crash in Name_resolution_context::process_error

mysql-test/r/subselect_sj_mat.result

@@ -312,7 +312,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 3	SUBQUERY	t2i	index	it2i1,it2i2,it2i3	#	#	#	5	100.00	#
 3	SUBQUERY	t3i	index	it3i1,it3i2,it3i3	#	#	#	4	75.00	#
 Warnings:
-Note	1003	select `test`.`t1i`.`a1` AS `a1`,`test`.`t1i`.`a2` AS `a2` from `test`.`t1i` semi join (`test`.`t2i`) semi join (`test`.`t2i` join `test`.`t3i`) where ((`test`.`t2i`.`b2` = `test`.`t3i`.`c2`) and (`test`.`t2i`.`b1` = `test`.`t3i`.`c1`) and (`test`.`t2i`.`b1` > '0') and (`test`.`t3i`.`c2` > '0'))
+Note	1003	select `test`.`t1i`.`a1` AS `a1`,`test`.`t1i`.`a2` AS `a2` from `test`.`t1i` semi join (`test`.`t2i`) semi join (`test`.`t2i` join `test`.`t3i`) where ((`test`.`t3i`.`c2` = `test`.`t2i`.`b2`) and (`test`.`t3i`.`c1` = `test`.`t2i`.`b1`) and (`test`.`t2i`.`b1` > '0') and (`test`.`t2i`.`b2` > '0'))
 select * from t1i
 where (a1, a2) in (select b1, b2 from t2i where b1 >  '0') and
 (a1, a2) in (select c1, c2 from t3i
@@ -402,7 +402,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 9	SUBQUERY	t3i	index	it3i1,it3i2,it3i3	#	#	#	4	75.00	#
 NULL	UNION RESULT	<union1,7>	ALL	NULL	#	#	#	NULL	NULL	#
 Warnings:
-Note	1003	(select `test`.`t1`.`a1` AS `a1`,`test`.`t1`.`a2` AS `a2` from  <materialize> (select `test`.`t2`.`b1` AS `b1`,`test`.`t2`.`b2` AS `b2` from `test`.`t2` where (<in_optimizer>(`test`.`t2`.`b2`,`test`.`t2`.`b2` in ( <materialize> (select `test`.`t3`.`c2` AS `c2` from `test`.`t3` where (`test`.`t3`.`c2` like '%02') ), <primary_index_lookup>(`test`.`t2`.`b2` in <temporary table> on distinct_key where ((`test`.`t2`.`b2` = `<subquery3>`.`c2`))))) or <in_optimizer>(`test`.`t2`.`b2`,`test`.`t2`.`b2` in ( <materialize> (select `test`.`t3`.`c2` AS `c2` from `test`.`t3` where (`test`.`t3`.`c2` like '%03') ), <primary_index_lookup>(`test`.`t2`.`b2` in <temporary table> on distinct_key where ((`test`.`t2`.`b2` = `<subquery4>`.`c2`)))))) group by `test`.`t2`.`b1`,`test`.`t2`.`b2`) semi join (`test`.`t2i` join `test`.`t3`) join `test`.`t1` where ((`test`.`t3`.`c2` = `<subquery2>`.`b2`) and (`test`.`t1`.`a2` = `<subquery2>`.`b2`) and (`test`.`t2i`.`b2` = `<subquery2>`.`b2`) and (`test`.`t3`.`c1` = `<subquery2>`.`b1`) and (`test`.`t1`.`a1` = `<subquery2>`.`b1`) and (`test`.`t2i`.`b1` = `<subquery2>`.`b1`) and (`<subquery2>`.`b2` > '0'))) union (select `test`.`t1i`.`a1` AS `a1`,`test`.`t1i`.`a2` AS `a2` from `test`.`t1i` semi join (`test`.`t2i`) semi join (`test`.`t2i` join `test`.`t3i`) where ((`test`.`t2i`.`b2` = `test`.`t3i`.`c2`) and (`test`.`t2i`.`b1` = `test`.`t3i`.`c1`) and (`test`.`t2i`.`b1` > '0') and (`test`.`t3i`.`c2` > '0')))
+Note	1003	(select `test`.`t1`.`a1` AS `a1`,`test`.`t1`.`a2` AS `a2` from  <materialize> (select `test`.`t2`.`b1` AS `b1`,`test`.`t2`.`b2` AS `b2` from `test`.`t2` where (<in_optimizer>(`test`.`t2`.`b2`,`test`.`t2`.`b2` in ( <materialize> (select `test`.`t3`.`c2` AS `c2` from `test`.`t3` where (`test`.`t3`.`c2` like '%02') ), <primary_index_lookup>(`test`.`t2`.`b2` in <temporary table> on distinct_key where ((`test`.`t2`.`b2` = `<subquery3>`.`c2`))))) or <in_optimizer>(`test`.`t2`.`b2`,`test`.`t2`.`b2` in ( <materialize> (select `test`.`t3`.`c2` AS `c2` from `test`.`t3` where (`test`.`t3`.`c2` like '%03') ), <primary_index_lookup>(`test`.`t2`.`b2` in <temporary table> on distinct_key where ((`test`.`t2`.`b2` = `<subquery4>`.`c2`)))))) group by `test`.`t2`.`b1`,`test`.`t2`.`b2`) semi join (`test`.`t2i` join `test`.`t3`) join `test`.`t1` where ((`test`.`t3`.`c2` = `<subquery2>`.`b2`) and (`test`.`t1`.`a2` = `<subquery2>`.`b2`) and (`test`.`t2i`.`b2` = `<subquery2>`.`b2`) and (`test`.`t3`.`c1` = `<subquery2>`.`b1`) and (`test`.`t1`.`a1` = `<subquery2>`.`b1`) and (`test`.`t2i`.`b1` = `<subquery2>`.`b1`) and (`<subquery2>`.`b2` > '0'))) union (select `test`.`t1i`.`a1` AS `a1`,`test`.`t1i`.`a2` AS `a2` from `test`.`t1i` semi join (`test`.`t2i`) semi join (`test`.`t2i` join `test`.`t3i`) where ((`test`.`t3i`.`c2` = `test`.`t2i`.`b2`) and (`test`.`t3i`.`c1` = `test`.`t2i`.`b1`) and (`test`.`t2i`.`b1` > '0') and (`test`.`t2i`.`b2` > '0')))
 (select * from t1
 where (a1, a2) in (select b1, b2 from t2
 where b2 in (select c2 from t3 where c2 LIKE '%02') or

sql/item_subselect.h

@@ -384,14 +384,7 @@ class Item_in_subselect :public Item_exists_subselect
   enum_exec_method exec_method;
 
   /*
-    JTBM: temporary measure to tell JTBM predicates from SJ predicates
-    psergey-jtbm-todo: can't we do without this?
-     - either remove it altogether
-     - or put into enum_exec_method
-    
-    We can't remove it altogether as it is used to classify contents in
-    join->sj_subselects.
-    jtbm-todo: option 1: let sj_subselects list pairs.
+    TRUE<=>this is a flattenable semi-join, false overwise.
   */
   bool is_flattenable_semijoin;
   

sql/opt_subselect.cc

@@ -2663,7 +2663,7 @@ bool setup_sj_materialization(JOIN_TAB *sjm_tab)
     DBUG_RETURN(TRUE); /* purecov: inspected */
   sjm->table->file->extra(HA_EXTRA_WRITE_CACHE);
   sjm->table->file->extra(HA_EXTRA_IGNORE_DUP_KEY);
-  //psergey2-todo: need this or can take advantage of re-init functionality?
+
   tab->join->sj_tmp_tables.push_back(sjm->table);
   tab->join->sjm_info_list.push_back(sjm);
   

sql/sql_select.cc

@@ -2112,7 +2112,7 @@ JOIN::exec()
 	  WHERE clause for any tables after the sorted one.
 	*/
 	JOIN_TAB *curr_table= &curr_join->join_tab[curr_join->const_tables+1];
-	JOIN_TAB *end_table= &curr_join->join_tab[curr_join->tables]; //psergey2-todo: check this!
+	JOIN_TAB *end_table= &curr_join->join_tab[curr_join->top_jtrange_tables];
 	for (; curr_table < end_table ; curr_table++)
 	{
 	  /*
@@ -5750,8 +5750,8 @@ void calc_used_field_length(THD *thd, JOIN_TAB *join_tab)
     rec_length+=(uint) max(4,blob_length);
   }  
   /*
-    psergey-todo: why we don't count here rowid that we might need to store
-    when using DuplicateElimination?
+    TODO: why we don't count here rowid that we might need to store when 
+    using DuplicateElimination?
   */
   join_tab->used_fields=fields;
   join_tab->used_fieldlength=rec_length;
@@ -6628,8 +6628,12 @@ make_outerjoin_info(JOIN *join)
          tab != jt_range->end; tab++)
     {
       TABLE *table=tab->table;
+      /* 
+        psergey: The following is probably incorrect, fix it when we get 
+        semi+outer joins processing to work: 
+      */
       if (!table)
-        continue; //psergey2: fix this when we get SJM+outer joins really working.
+        continue;
       TABLE_LIST *tbl= table->pos_in_table_list;
       TABLE_LIST *embedding= tbl->embedding;
 
@@ -6766,15 +6770,13 @@ make_join_select(JOIN *join,SQL_SELECT *select,COND *cond)
     uint i= join->const_tables;
     for (tab= next_depth_first_tab(join, NULL); tab; 
          tab= next_depth_first_tab(join, tab), i++)
-    //for (uint i=join->const_tables ; i < join->tables ; i++)
     {
-      //tab= join->join_tab+i;
       /*
         first_inner is the X in queries like:
         SELECT * FROM t1 LEFT OUTER JOIN (t2 JOIN t3) ON X
       */
       JOIN_TAB *first_inner_tab= tab->first_inner;
-      //psergey2-todo: change this to table bitmap.
+
       if (tab->table)
         current_map= tab->table->map;
       else
@@ -7051,8 +7053,6 @@ make_join_select(JOIN *join,SQL_SELECT *select,COND *cond)
       */ 
 
       /* First push down constant conditions from on expressions */
-      //for (JOIN_TAB *join_tab= join->join_tab+join->const_tables;
-      //     join_tab < join->join_tab+join->tables ; join_tab++)
       for (JOIN_TAB *join_tab= first_linear_tab(join, TRUE); 
            join_tab; 
            join_tab= next_linear_tab(join, join_tab, FALSE))
@@ -7098,7 +7098,10 @@ make_join_select(JOIN *join,SQL_SELECT *select,COND *cond)
         {
           if (!tab->table)
           {
-            //psergey3-todo: this is probably incorrect:
+            /* 
+              psergey-todo: this is probably incorrect, fix this when we get
+              correct processing for outer joins + semi joins 
+            */
             continue;
           }
           current_map= tab->table->map;
@@ -7503,10 +7506,7 @@ uint check_join_cache_usage(JOIN_TAB *tab,
 
   if (options & SELECT_NO_JOIN_CACHE)
     goto no_join_cache;
-  /* 
-    psergey-todo: why the below when execution code seems to handle the
-    "range checked for each record" case?
-  */
+
   if (tab->use_quick == 2)
     goto no_join_cache;
   /*
@@ -7937,7 +7937,6 @@ void JOIN_TAB::cleanup()
   select= 0;
   delete quick;
   quick= 0;
-  //psergey3-todo: empty merged SJM temptables here.
   if (cache)
   {
     cache->free();
@@ -8455,7 +8454,6 @@ static void clear_tables(JOIN *join)
     must clear only the non-const tables, as const tables
     are not re-calculated.
   */
-  // psergey2: What is this for? perhaps, we should reset the SJM temptables, too??
   for (uint i= 0 ; i < join->tables ; i++)
   {
     if (!(join->table[i]->map & join->const_table_map))
@@ -9282,16 +9280,20 @@ static int compare_fields_by_table_order(Item_field *field1,
   JOIN_TAB **idx= (JOIN_TAB **) table_join_idx;
   
   JOIN_TAB *tab1= idx[field1->field->table->tablenr];
+  JOIN_TAB *tab2= idx[field2->field->table->tablenr];
+  
   /* 
-    if a table is inside a merged sjm nest, then it compares as its join-bush
-    psergey-5-todo: compare fairly!
+    if one of the table is inside a merged SJM nest and another one isn't,
+    compare SJM bush roots of the tables.
   */
+  if (tab1->bush_root_tab != tab2->bush_root_tab)
+  {
     if (tab1->bush_root_tab)
       tab1= tab1->bush_root_tab;
 
-  JOIN_TAB *tab2= idx[field2->field->table->tablenr];
     if (tab2->bush_root_tab)
       tab2= tab2->bush_root_tab;
+  }
   
   cmp= tab2 - tab1;
 

sql/sql_select.h

@@ -187,11 +187,11 @@ typedef struct st_join_table {
   st_join_table *first_unmatched; /**< used for optimization purposes only     */
 
   /*
-    psergey2:  for join tabs that are inside a bush: root of this bush.
+    For join tabs that are inside an SJM bush: root of the bush
   */
   st_join_table *bush_root_tab;
 
-  /* TRUE <=> This join_tab is inside a join bush and is the last leaf tab here */
+  /* TRUE <=> This join_tab is inside an SJM bush and is the last leaf tab here */
   bool          last_leaf_in_bush;
   
   /*