SQL: TRUNCATE FOR SYSTEM_TIME BEFORE [closes #111]

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

@@ -111,5 +111,53 @@ select * from t for system_time all;
 a
 9
 8
+create or replace table t (a int) with system versioning;
+insert into t values (1), (2);
+update t set a=11 where a=1;
+set @ts1=now(6);
+update t set a=22 where a=2;
+select * from t for system_time all;
+a
+11
+22
+1
+2
+truncate t for system_time before timestamp @ts1;
+select * from t for system_time all;
+a
+11
+22
+2
+truncate t for system_time before timestamp now(6);
+select * from t for system_time all;
+a
+11
+22
+create or replace table t (a int) with system versioning engine=innodb;
+insert into t values (1), (2);
+update t set a=11 where a=1;
+set @ts1=now(6);
+update t set a=22 where a=2;
+select * from t for system_time all;
+a
+11
+22
+1
+2
+truncate t for system_time before timestamp @ts1;
+select * from t for system_time all;
+a
+11
+22
+1
+2
+truncate t for system_time before timestamp now(6);
+select * from t for system_time all;
+a
+11
+22
+2
+select * from t for system_time before timestamp now();
+ERROR HY000: `FOR SYSTEM_TIME BEFORE` works only with `TRUNCATE` query type
 drop table t;
 drop procedure truncate_history_of_t;

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

@@ -90,5 +90,30 @@ update t set a=9;
 truncate t for system_time timestamp between '1-1-1' and @ts2;
 select * from t for system_time all;
 
+create or replace table t (a int) with system versioning;
+insert into t values (1), (2);
+update t set a=11 where a=1;
+set @ts1=now(6);
+update t set a=22 where a=2;
+select * from t for system_time all;
+truncate t for system_time before timestamp @ts1;
+select * from t for system_time all;
+truncate t for system_time before timestamp now(6);
+select * from t for system_time all;
+
+create or replace table t (a int) with system versioning engine=innodb;
+insert into t values (1), (2);
+update t set a=11 where a=1;
+set @ts1=now(6);
+update t set a=22 where a=2;
+select * from t for system_time all;
+truncate t for system_time before timestamp @ts1;
+select * from t for system_time all;
+truncate t for system_time before timestamp now(6);
+select * from t for system_time all;
+
+--error ER_VERS_WRONG_QUERY_TYPE
+select * from t for system_time before timestamp now();
+
 drop table t;
 drop procedure truncate_history_of_t;

sql/share/errmsg-utf8.txt

@@ -7525,3 +7525,6 @@ WARN_VERS_PART_ROTATION
 
 ER_VERS_NOT_ALLOWED
         eng "%`s is not allowed for versioned table"
+
+ER_VERS_WRONG_QUERY_TYPE
+        eng "%`s works only with %`s query type"

sql/sql_delete.cc

@@ -283,12 +283,17 @@ bool mysql_delete(THD *thd, TABLE_LIST *table_list, COND *conds,
       DBUG_RETURN(TRUE);
 
     // trx_sees() in InnoDB reads sys_trx_start
-    if (!table->versioned_by_sql() &&
+    if (!table->versioned_by_sql()) {
-        (select_lex->vers_conditions.type == FOR_SYSTEM_TIME_BETWEEN ||
+      if (select_lex->vers_conditions.type == FOR_SYSTEM_TIME_BETWEEN ||
-         select_lex->vers_conditions.type == FOR_SYSTEM_TIME_FROM_TO))
+          select_lex->vers_conditions.type == FOR_SYSTEM_TIME_FROM_TO)
       {
         bitmap_set_bit(table->read_set, table->vers_start_field()->field_index);
       }
+      else if (select_lex->vers_conditions.type == FOR_SYSTEM_TIME_BEFORE)
+      {
+        bitmap_set_bit(table->read_set, table->vers_end_field()->field_index);
+      }
+    }
   }
 
   if (mysql_handle_list_of_derived(thd->lex, table_list, DT_MERGE_FOR_INSERT))

sql/sql_select.cc

@@ -762,6 +762,14 @@ int vers_setup_select(THD *thd, TABLE_LIST *tables, COND **where_expr,
         table->vers_conditions.type == FOR_SYSTEM_TIME_UNSPECIFIED ?
           slex->vers_conditions : table->vers_conditions;
 
+      if (vers_conditions.type == FOR_SYSTEM_TIME_BEFORE &&
+          thd->lex->sql_command != SQLCOM_TRUNCATE)
+      {
+        my_error(ER_VERS_WRONG_QUERY_TYPE, MYF(0), "FOR SYSTEM_TIME BEFORE",
+                 "TRUNCATE");
+        DBUG_RETURN(-1);
+      }
+
       if (vers_conditions.type != FOR_SYSTEM_TIME_UNSPECIFIED)
       {
         switch (slex->lock_type)
@@ -869,6 +877,10 @@ int vers_setup_select(THD *thd, TABLE_LIST *tables, COND **where_expr,
           cond2= newx Item_func_ge(thd, row_end,
             vers_conditions.start);
           break;
+        case FOR_SYSTEM_TIME_BEFORE:
+          cond1= newx Item_func_lt(thd, row_end,
+            vers_conditions.start);
+          break;
         default:
           DBUG_ASSERT(0);
         }
@@ -912,6 +924,12 @@ int vers_setup_select(THD *thd, TABLE_LIST *tables, COND **where_expr,
             newx Item_func_vtq_trx_sees_eq(thd, trx_id1, row_start);
           cond2= newx Item_func_vtq_trx_sees_eq(thd, row_end, trx_id0);
           break;
+        case FOR_SYSTEM_TIME_BEFORE:
+          trx_id0= vers_conditions.unit == UNIT_TIMESTAMP ?
+            newx Item_func_vtq_id(thd, vers_conditions.start, VTQ_TRX_ID) :
+            vers_conditions.start;
+          cond1= newx Item_func_lt(thd, row_end, trx_id0);
+          break;
         default:
           DBUG_ASSERT(0);
         }

sql/sql_yacc.yy

@@ -8880,6 +8880,12 @@ for_system_time_expr:
           {
             Lex->vers_conditions.init(FOR_SYSTEM_TIME_BETWEEN, $1, $3, $5);
           }
+        | BEFORE_SYM
+          trans_or_timestamp
+          simple_expr
+          {
+            Lex->vers_conditions.init(FOR_SYSTEM_TIME_BEFORE, $2, $3);
+          }
         ;
 
 select_option_list:

sql/table.h

@@ -1847,7 +1847,8 @@ enum vers_range_type_t
   FOR_SYSTEM_TIME_AS_OF,
   FOR_SYSTEM_TIME_FROM_TO,
   FOR_SYSTEM_TIME_BETWEEN,
-  FOR_SYSTEM_TIME_ALL
+  FOR_SYSTEM_TIME_ALL,
+  FOR_SYSTEM_TIME_BEFORE
 };
 
 enum vers_range_unit_t