SQL: inner/outer system_time consistency [fixes #384]

mysql-test/suite/versioning/r/derived.result

@@ -96,9 +96,10 @@ where name = 'bill'
   for system_time as of timestamp @ts
 union
 select ee.emp_id, ee.name, ee.mgr
-from emp as ee, ancestors as a
+from emp
+for system_time as of timestamp @ts as ee,
+ancestors as a
 where ee.mgr = a.emp_id
-for system_time as of timestamp @ts
 )
 select * from ancestors;
 emp_id	name	mgr
@@ -116,9 +117,9 @@ as
   for system_time as of timestamp @ts
   union
   select ee.emp_id, ee.name, ee.mgr
-  from emp as ee, ancestors as a
+  from emp for system_time as of timestamp @ts as ee,
+  ancestors as a
   where ee.mgr = a.emp_id
-  for system_time as of timestamp @ts
 )
 select * from ancestors";
 prepare stmt from @tmp;
@@ -154,16 +155,6 @@ y	x
 with s3 as (select *, t1.sys_trx_end from t2, t1 for system_time as of timestamp @t0) select * from s3;
 y	x
 10	1
-# SYSTEM_TIME propagation from outer to inner
-select * from (select *, t1.sys_trx_start from t2 for system_time as of current_timestamp, t1) as s4 for system_time as of timestamp @t0;
-y	x
-10	1
-with s5 as (select *, t1.sys_trx_start from t2 for system_time as of current_timestamp, t1) select * from s5 for system_time as of timestamp @t0;
-y	x
-10	1
-with s6 as (select *, t1.sys_trx_start from t2 for system_time as of current_timestamp, t1) select * from s6 for system_time as of timestamp @t0;
-y	x
-10	1
 ### VIEW instead of t1
 set @q= concat("create view vt1 as select * from t1 for system_time as of timestamp '", @t0, "'");
 prepare q from @q;
@@ -216,6 +207,18 @@ create or replace table t1 (x int, y int) with system versioning;
 create or replace table t2 (x int, y int) with system versioning;
 insert into t1 values (1, 1), (1, 2), (1, 3), (4, 4), (5, 5);
 insert into t2 values (1, 2), (2, 1), (3, 1);
+## Outer or inner SYSTEM_TIME produces same expression
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	5	100.00	Using where; Using join buffer (flat, BNL join)
+Query A:
+Note	1003	select `test`.`t1`.`x` AS `x`,`test`.`t1`.`y` AS `y1`,`test`.`t2`.`x` AS `x2`,`test`.`t2`.`y` AS `y2` from `test`.`t1` FOR SYSTEM_TIME ALL join `test`.`t2` FOR SYSTEM_TIME ALL where `test`.`t1`.`x` = `test`.`t2`.`x` and `test`.`t1`.`sys_trx_end` > <cache>(current_timestamp(6)) and `test`.`t1`.`sys_trx_start` <= <cache>(current_timestamp(6)) and `test`.`t2`.`sys_trx_end` > <cache>(current_timestamp(6)) and `test`.`t2`.`sys_trx_start` <= <cache>(current_timestamp(6))
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	5	100.00	Using where; Using join buffer (flat, BNL join)
+Query B:
+Note	1003	select `test`.`t1`.`x` AS `x`,`test`.`t1`.`y` AS `y1`,`test`.`t2`.`x` AS `x2`,`test`.`t2`.`y` AS `y2` from `test`.`t1` FOR SYSTEM_TIME ALL join `test`.`t2` FOR SYSTEM_TIME ALL where `test`.`t1`.`x` = `test`.`t2`.`x` and `test`.`t1`.`sys_trx_end` > <cache>(current_timestamp(6)) and `test`.`t1`.`sys_trx_start` <= <cache>(current_timestamp(6)) and `test`.`t2`.`sys_trx_end` > <cache>(current_timestamp(6)) and `test`.`t2`.`sys_trx_start` <= <cache>(current_timestamp(6))
+Fine result: queries A and B are equal.
 ## LEFT JOIN: t1, t2 versioned
 select * from (
 select t1.x as LJ1_x1, t1.y as y1, t2.x as x2, t2.y as y2

mysql-test/suite/versioning/t/derived.test

@@ -67,9 +67,10 @@ as
   for system_time as of timestamp @ts
   union
   select ee.emp_id, ee.name, ee.mgr
-  from emp as ee, ancestors as a
+  from emp
+  for system_time as of timestamp @ts as ee,
+  ancestors as a
   where ee.mgr = a.emp_id
-  for system_time as of timestamp @ts
 )
 select * from ancestors;
 set @tmp= "
@@ -83,9 +84,9 @@ as
   for system_time as of timestamp @ts
   union
   select ee.emp_id, ee.name, ee.mgr
-  from emp as ee, ancestors as a
+  from emp for system_time as of timestamp @ts as ee,
+  ancestors as a
   where ee.mgr = a.emp_id
-  for system_time as of timestamp @ts
 )
 select * from ancestors";
 prepare stmt from @tmp; execute stmt; drop prepare stmt;
@@ -111,10 +112,6 @@ with s1 as (select * from t1 for system_time as of timestamp @t0, t2) select * f
 --echo # leading table selection
 select * from (select *, t1.sys_trx_end from t2, t1 for system_time as of timestamp @t0) as s2;
 with s3 as (select *, t1.sys_trx_end from t2, t1 for system_time as of timestamp @t0) select * from s3;
---echo # SYSTEM_TIME propagation from outer to inner
-select * from (select *, t1.sys_trx_start from t2 for system_time as of current_timestamp, t1) as s4 for system_time as of timestamp @t0;
-with s5 as (select *, t1.sys_trx_start from t2 for system_time as of current_timestamp, t1) select * from s5 for system_time as of timestamp @t0;
-with s6 as (select *, t1.sys_trx_start from t2 for system_time as of current_timestamp, t1) select * from s6 for system_time as of timestamp @t0;
 
 --echo ### VIEW instead of t1
 set @q= concat("create view vt1 as select * from t1 for system_time as of timestamp '", @t0, "'");
@@ -156,6 +153,36 @@ create or replace table t2 (x int, y int) with system versioning;
 insert into t1 values (1, 1), (1, 2), (1, 3), (4, 4), (5, 5);
 insert into t2 values (1, 2), (2, 1), (3, 1);
 
+--echo ## Outer or inner SYSTEM_TIME produces same expression
+
+--disable_warnings
+--disable_query_log
+explain extended
+select * from (
+  select t1.x, t1.y as y1, t2.x as x2, t2.y as y2
+  from t1 join t2 on t1.x = t2.x) for system_time as of now() as t;
+
+let $a=`show warnings`;
+--echo Query A:
+echo $a;
+
+explain extended
+select * from (
+  select t1.x, t1.y as y1, t2.x as x2, t2.y as y2
+  from t1 for system_time as of now()
+  join t2 for system_time as of now() on t1.x = t2.x) as t;
+
+let $b=`show warnings`;
+--echo Query B:
+echo $b;
+
+if ($a == $b)
+{
+  --echo Fine result: queries A and B are equal.
+}
+--enable_query_log
+--enable_warnings
+
 --echo ## LEFT JOIN: t1, t2 versioned
 select * from (
   select t1.x as LJ1_x1, t1.y as y1, t2.x as x2, t2.y as y2

sql/sql_derived.cc

@@ -849,8 +849,6 @@ expli_table_err:
           if (!expli_end && (res= sl->vers_push_field(thd, impli_table, impli_end)))
             goto exit;
         }
-
-        sl->vers_check_clash= impli_table->vers_conditions;
       }
     } // if (sl->table_list.elements > 0)
     // System Versioning end

sql/sql_lex.cc

@@ -2312,7 +2312,6 @@ void st_select_lex::init_select()
   curr_tvc_name= 0;
   in_tvc= false;
   vers_saved_where= NULL;
-  vers_check_clash= false;
   versioned_tables= 0;
 }
 

sql/sql_lex.h

@@ -1048,7 +1048,6 @@ public:
 private:
   Item *vers_saved_where;
 public:
-  bool vers_check_clash;
   uint versioned_tables;
   int vers_setup_conds(THD *thd, TABLE_LIST *tables, COND **where_expr);
   /* push new Item_field into item_list */

sql/sql_select.cc

@@ -797,17 +797,23 @@ int SELECT_LEX::vers_setup_conds(THD *thd, TABLE_LIST *tables, COND **where_expr
     }
   }
 
-  SELECT_LEX *outer_slex= next_select_in_list();
+  // find outer system_time
-  // propagate derived conditions to outer SELECT_LEX
+  SELECT_LEX *outer_slex= outer_select();
-  if (outer_slex && vers_check_clash)
+  TABLE_LIST* outer_table= NULL;
+
+  if (outer_slex)
   {
-    for (table= outer_slex->table_list.first; table; table= table->next_local)
+    TABLE_LIST* derived= master_unit()->derived;
+    // inner SELECT may not be a derived table (derived == NULL)
+    while (derived && outer_slex && !derived->vers_conditions)
     {
-      if (table->vers_conditions && !is_linkage_set())
+      derived= outer_slex->master_unit()->derived;
-      {
+      outer_slex= outer_slex->outer_select();
-        my_error(ER_VERS_SYSTEM_TIME_CLASH, MYF(0), table->alias);
+    }
-        DBUG_RETURN(-1);
+    if (derived && outer_slex)
-      }
+    {
+      DBUG_ASSERT(derived->vers_conditions);
+      outer_table= derived;
     }
   }
 
@@ -821,20 +827,17 @@ int SELECT_LEX::vers_setup_conds(THD *thd, TABLE_LIST *tables, COND **where_expr
 
     vers_select_conds_t &vers_conditions= table->vers_conditions;
 
-    // propagate system_time from nearest outer SELECT_LEX
+    if (outer_table && table != outer_table) // inner table may be outer in recursive CTE
-    if (!vers_conditions && outer_slex)
     {
-      TABLE_LIST* derived= master_unit()->derived;
+      if (vers_conditions)
-      // inner SELECT may not be a derived table (derived == NULL)
-      while (derived && outer_slex && !derived->vers_conditions)
       {
-        derived= outer_slex->master_unit()->derived;
+        my_error(ER_VERS_SYSTEM_TIME_CLASH, MYF(0), outer_table->alias);
-        outer_slex= outer_slex->next_select_in_list();
+        DBUG_RETURN(-1);
       }
-      if (derived && outer_slex)
+      else
       {
-        DBUG_ASSERT(derived->vers_conditions);
+        // propagate system_time from nearest outer SELECT_LEX
-        vers_conditions= derived->vers_conditions;
+        vers_conditions= outer_table->vers_conditions;
       }
     }
 
@@ -1022,6 +1025,9 @@ int SELECT_LEX::vers_setup_conds(THD *thd, TABLE_LIST *tables, COND **where_expr
       this->where= *dst_cond;
       this->where->top_level_item();
     }
+
+    if (outer_table)
+      outer_table->vers_conditions.type= FOR_SYSTEM_TIME_ALL;
   }
 
   DBUG_RETURN(0);