Bug#11761296: 53775: QUERY ON PARTITIONED TABLE RETURNS CACHED

                                        RESULT FROM PREVIOUS TRANSACTION

The current Query Cache API is not fully compatible with
the partitioning engine.

There is no good way to implement support for QC due to:
1) a static callback for ha_partition would need to have access
to all partition names and call the underlying callback for each
[sub]partition with the correct name.
2) pruning would be impossible, even if one used the ulonglong
engine_data due to if engine_data is changed, the table is
invalidated by the QC.

So the only viable solution to avoid incorrect data is to not allow
caching of queries using partitioned tables.

(There are some extra changes, due to removal of \r as line break)

mysql-test/include/query_cache.inc

@@ -4,6 +4,9 @@
 #     $engine_type       -- storage engine to be tested
 #     $test_foreign_keys -- 0, skip foreign key tests
 #                        -- 1, do not skip foreign key tests
+#     $partitions_a      -- partition by column 'a'
+#     $partitions_id     -- partition by column 'id'
+#     $partitions_s1     -- partition by column 's1'
 # have to be set before sourcing this script.
 #
 # Last update:
@@ -19,47 +22,61 @@ eval SET SESSION STORAGE_ENGINE = $engine_type;
 drop table if exists t1,t2,t3;
 --enable_warnings
 
+set @save_query_cache_size = @@global.query_cache_size;
+set GLOBAL query_cache_size = 1355776;
+
 #
 # Without auto_commit.
 #
 flush status;
 set autocommit=0;
-create table t1 (a int not null);
+eval create table t1 (a int not null)$partitions_a;
 insert into t1 values (1),(2),(3);
+--sorted_result
 select * from t1;
 show status like "Qcache_queries_in_cache";
 drop table t1;
 commit;
 set autocommit=1;
 begin;
-create table t1 (a int not null);
+eval create table t1 (a int not null)$partitions_a;
 insert into t1 values (1),(2),(3);
+--sorted_result
 select * from t1;
 show status like "Qcache_queries_in_cache";
 drop table t1;
 commit;
-create table t1 (a int not null);
-create table t2 (a int not null);
-create table t3 (a int not null);
+eval create table t1 (a int not null)$partitions_a;
+eval create table t2 (a int not null)$partitions_a;
+eval create table t3 (a int not null)$partitions_a;
 insert into t1 values (1),(2);
 insert into t2 values (1),(2);
 insert into t3 values (1),(2);
+--sorted_result
 select * from t1;
+--sorted_result
 select * from t2;
+--sorted_result
 select * from t3;
 show status like "Qcache_queries_in_cache";
 show status like "Qcache_hits";
 begin;
+--sorted_result
 select * from t1;
+--sorted_result
 select * from t2;
+--sorted_result
 select * from t3;
 show status like "Qcache_queries_in_cache";
 show status like "Qcache_hits";
 insert into t1 values (3);
 insert into t2 values (3);
 insert into t1 values (4);
+--sorted_result
 select * from t1;
+--sorted_result
 select * from t2;
+--sorted_result
 select * from t3;
 show status like "Qcache_queries_in_cache";
 show status like "Qcache_hits";
@@ -67,7 +84,7 @@ commit;
 show status like "Qcache_queries_in_cache";
 drop table t3,t2,t1;
 
-CREATE TABLE t1 (id int(11) NOT NULL auto_increment, PRIMARY KEY  (id));
+eval CREATE TABLE t1 (id int(11) NOT NULL auto_increment, PRIMARY KEY (id))$partitions_id;
 select count(*) from t1;
 insert into t1 (id) values (0);
 select count(*) from t1;
@@ -78,8 +95,6 @@ if ($test_foreign_keys)
 #
 # one statement roll back inside transation
 #
-let $save_query_cache_size=`select @@global.query_cache_size`;
-set GLOBAL query_cache_size=1355776;
 CREATE TABLE t1 ( id int(10) NOT NULL auto_increment, a varchar(25) default NULL, PRIMARY KEY  (id), UNIQUE KEY a (a));
 CREATE TABLE t2 ( id int(10) NOT NULL auto_increment, b varchar(25) default NULL, PRIMARY KEY  (id), UNIQUE KEY b (b));
 CREATE TABLE t3 ( id int(10) NOT NULL auto_increment, t1_id int(10) NOT NULL default '0', t2_id int(10) NOT NULL default '0', state int(11) default NULL, PRIMARY KEY  (id), UNIQUE KEY t1_id (t1_id,t2_id), KEY t2_id (t2_id,t1_id), CONSTRAINT `t3_ibfk_1` FOREIGN KEY (`t1_id`) REFERENCES `t1` (`id`), CONSTRAINT `t3_ibfk_2` FOREIGN KEY (`t2_id`) REFERENCES `t2` (`id`));
@@ -95,9 +110,6 @@ insert into t3 VALUES ( NULL, 1, 1, 2 );
 commit;
 select t1.* from t1, t2, t3 where t3.state & 1 = 0 and t3.t1_id = t1.id and t3.t2_id = t2.id and t1.id = 1 order by t1.a asc;
 drop table t3,t2,t1;
---disable_query_log
-eval set GLOBAL query_cache_size=$save_query_cache_size;
---enable_query_log
 }
 
 #
@@ -118,7 +130,7 @@ SET GLOBAL query_cache_size = 200000;
 flush status;
 SET @@autocommit=1;
 eval SET SESSION STORAGE_ENGINE = $engine_type;
-CREATE TABLE t2 (s1 int, s2 varchar(1000), key(s1));
+eval CREATE TABLE t2 (s1 int, s2 varchar(1000), key(s1))$partitions_s1;
 INSERT INTO t2 VALUES (1,repeat('a',10)),(2,repeat('a',10)),(3,repeat('a',10)),(4,repeat('a',10));
 COMMIT;
 START TRANSACTION;
@@ -176,8 +188,8 @@ show status like "Qcache_queries_in_cache";
 show status like "Qcache_hits";
 
 # Final cleanup
-eval set GLOBAL query_cache_size=$save_query_cache_size;
 disconnect connection1;
 --source include/wait_until_disconnected.inc
 connection default;
+set @@global.query_cache_size = @save_query_cache_size;
 drop table t2;

mysql-test/r/cache_innodb.result

 SET SESSION STORAGE_ENGINE = InnoDB;
 drop table if exists t1,t2,t3;
+set @save_query_cache_size = @@global.query_cache_size;
+set GLOBAL query_cache_size = 1355776;
 flush status;
 set autocommit=0;
 create table t1 (a int not null);
@@ -109,7 +111,6 @@ select count(*) from t1;
 count(*)
 1
 drop table t1;
-set GLOBAL query_cache_size=1355776;
 CREATE TABLE t1 ( id int(10) NOT NULL auto_increment, a varchar(25) default NULL, PRIMARY KEY  (id), UNIQUE KEY a (a));
 CREATE TABLE t2 ( id int(10) NOT NULL auto_increment, b varchar(25) default NULL, PRIMARY KEY  (id), UNIQUE KEY b (b));
 CREATE TABLE t3 ( id int(10) NOT NULL auto_increment, t1_id int(10) NOT NULL default '0', t2_id int(10) NOT NULL default '0', state int(11) default NULL, PRIMARY KEY  (id), UNIQUE KEY t1_id (t1_id,t2_id), KEY t2_id (t2_id,t1_id), CONSTRAINT `t3_ibfk_1` FOREIGN KEY (`t1_id`) REFERENCES `t1` (`id`), CONSTRAINT `t3_ibfk_2` FOREIGN KEY (`t2_id`) REFERENCES `t2` (`id`));
@@ -218,5 +219,5 @@ Qcache_queries_in_cache	1
 show status like "Qcache_hits";
 Variable_name	Value
 Qcache_hits	1
-set GLOBAL query_cache_size=1048576;
+set @@global.query_cache_size = @save_query_cache_size;
 drop table t2;

mysql-test/r/partition_cache.result

+SET SESSION STORAGE_ENGINE = InnoDB;
+drop table if exists t1,t2,t3;
+set @save_query_cache_size = @@global.query_cache_size;
+set GLOBAL query_cache_size = 1355776;
+flush status;
+set autocommit=0;
+create table t1 (a int not null) PARTITION BY KEY (a) PARTITIONS 3;
+insert into t1 values (1),(2),(3);
+select * from t1;
+a
+1
+2
+3
+show status like "Qcache_queries_in_cache";
+Variable_name	Value
+Qcache_queries_in_cache	0
+drop table t1;
+commit;
+set autocommit=1;
+begin;
+create table t1 (a int not null) PARTITION BY KEY (a) PARTITIONS 3;
+insert into t1 values (1),(2),(3);
+select * from t1;
+a
+1
+2
+3
+show status like "Qcache_queries_in_cache";
+Variable_name	Value
+Qcache_queries_in_cache	0
+drop table t1;
+commit;
+create table t1 (a int not null) PARTITION BY KEY (a) PARTITIONS 3;
+create table t2 (a int not null) PARTITION BY KEY (a) PARTITIONS 3;
+create table t3 (a int not null) PARTITION BY KEY (a) PARTITIONS 3;
+insert into t1 values (1),(2);
+insert into t2 values (1),(2);
+insert into t3 values (1),(2);
+select * from t1;
+a
+1
+2
+select * from t2;
+a
+1
+2
+select * from t3;
+a
+1
+2
+show status like "Qcache_queries_in_cache";
+Variable_name	Value
+Qcache_queries_in_cache	0
+show status like "Qcache_hits";
+Variable_name	Value
+Qcache_hits	0
+begin;
+select * from t1;
+a
+1
+2
+select * from t2;
+a
+1
+2
+select * from t3;
+a
+1
+2
+show status like "Qcache_queries_in_cache";
+Variable_name	Value
+Qcache_queries_in_cache	0
+show status like "Qcache_hits";
+Variable_name	Value
+Qcache_hits	0
+insert into t1 values (3);
+insert into t2 values (3);
+insert into t1 values (4);
+select * from t1;
+a
+1
+2
+3
+4
+select * from t2;
+a
+1
+2
+3
+select * from t3;
+a
+1
+2
+show status like "Qcache_queries_in_cache";
+Variable_name	Value
+Qcache_queries_in_cache	0
+show status like "Qcache_hits";
+Variable_name	Value
+Qcache_hits	0
+commit;
+show status like "Qcache_queries_in_cache";
+Variable_name	Value
+Qcache_queries_in_cache	0
+drop table t3,t2,t1;
+CREATE TABLE t1 (id int(11) NOT NULL auto_increment, PRIMARY KEY (id)) PARTITION BY HASH (id) PARTITIONS 3;
+select count(*) from t1;
+count(*)
+0
+insert into t1 (id) values (0);
+select count(*) from t1;
+count(*)
+1
+drop table t1;
+SET SESSION STORAGE_ENGINE = InnoDB;
+SET @@autocommit=1;
+connection default
+SHOW VARIABLES LIKE 'have_query_cache';
+Variable_name	Value
+have_query_cache	YES
+SET GLOBAL query_cache_size = 200000;
+flush status;
+SET @@autocommit=1;
+SET SESSION STORAGE_ENGINE = InnoDB;
+CREATE TABLE t2 (s1 int, s2 varchar(1000), key(s1)) PARTITION BY KEY (s1) PARTITIONS 3;
+INSERT INTO t2 VALUES (1,repeat('a',10)),(2,repeat('a',10)),(3,repeat('a',10)),(4,repeat('a',10));
+COMMIT;
+START TRANSACTION;
+SELECT sql_cache count(*) FROM t2 WHERE s2 = 'w';
+count(*)
+0
+UPDATE t2 SET s2 = 'w' WHERE s1 = 3;
+SELECT sql_cache count(*) FROM t2 WHERE s2 = 'w';
+count(*)
+1
+show status like "Qcache_queries_in_cache";
+Variable_name	Value
+Qcache_queries_in_cache	0
+connection connection1
+START TRANSACTION;
+SELECT sql_cache count(*) FROM t2 WHERE s2 = 'w';
+count(*)
+0
+INSERT INTO t2 VALUES (5,'w');
+SELECT sql_cache count(*) FROM t2 WHERE s2 = 'w';
+count(*)
+1
+COMMIT;
+SELECT sql_cache count(*) FROM t2 WHERE s2 = 'w';
+count(*)
+1
+show status like "Qcache_queries_in_cache";
+Variable_name	Value
+Qcache_queries_in_cache	0
+connection default
+SELECT sql_cache count(*) FROM t2 WHERE s2 = 'w';
+count(*)
+1
+COMMIT;
+show status like "Qcache_queries_in_cache";
+Variable_name	Value
+Qcache_queries_in_cache	0
+SELECT sql_cache count(*) FROM t2 WHERE s2 = 'w';
+count(*)
+2
+show status like "Qcache_queries_in_cache";
+Variable_name	Value
+Qcache_queries_in_cache	0
+connection connection1
+SELECT sql_cache count(*) FROM t2 WHERE s2 = 'w';
+count(*)
+2
+START TRANSACTION;
+SELECT sql_cache count(*) FROM t2 WHERE s2 = 'w';
+count(*)
+2
+INSERT INTO t2 VALUES (6,'w');
+SELECT sql_cache count(*) FROM t2 WHERE s2 = 'w';
+count(*)
+3
+connection default
+SELECT sql_cache count(*) FROM t2 WHERE s2 = 'w';
+count(*)
+2
+START TRANSACTION;
+SELECT sql_cache count(*) FROM t2 WHERE s2 = 'w';
+count(*)
+2
+DELETE from t2 WHERE s1=3;
+SELECT sql_cache count(*) FROM t2 WHERE s2 = 'w';
+count(*)
+1
+COMMIT;
+connection connection1
+COMMIT;
+SELECT sql_cache count(*) FROM t2 WHERE s2 = 'w';
+count(*)
+2
+show status like "Qcache_queries_in_cache";
+Variable_name	Value
+Qcache_queries_in_cache	0
+show status like "Qcache_hits";
+Variable_name	Value
+Qcache_hits	0
+set @@global.query_cache_size = @save_query_cache_size;
+drop table t2;

mysql-test/t/cache_innodb-master.opt

---set-variable=query_cache_size=1M

mysql-test/t/partition_cache.test

+# t/cache_innodb.test
+#
+# Last update:
+# 2006-07-26 ML test refactored (MySQL 5.1)
+#               main code t/innodb_cache.test --> include/query_cache.inc
+#               new wrapper t/cache_innodb.test
+#
+
+--source include/have_query_cache.inc
+
+--source include/have_innodb.inc
+--source include/have_partition.inc
+let $engine_type= InnoDB;
+# Using SELECT to get a space as first character.
+let $partitions_a= `SELECT ' PARTITION BY KEY (a) PARTITIONS 3'`;
+let $partitions_id= `SELECT ' PARTITION BY HASH (id) PARTITIONS 3'`;
+let $partitions_s1= `SELECT ' PARTITION BY KEY (s1) PARTITIONS 3'`;
+# partitioning does not support FOREIGN KEYs
+let $test_foreign_keys= 0;
+
+--source include/query_cache.inc

sql/ha_partition.h

@@ -553,6 +553,20 @@ class ha_partition :public handler
   virtual int extra(enum ha_extra_function operation);
   virtual int extra_opt(enum ha_extra_function operation, ulong cachesize);
   virtual int reset(void);
+  /*
+    Do not allow caching of partitioned tables, since we cannot return
+    a callback or engine_data that would work for a generic engine.
+  */
+  virtual my_bool register_query_cache_table(THD *thd, char *table_key,
+                                             uint key_length,
+                                             qc_engine_callback
+                                               *engine_callback,
+                                             ulonglong *engine_data)
+  {
+    *engine_callback= NULL;
+    *engine_data= 0;
+    return FALSE;
+  }
 
 private:
   static const uint NO_CURRENT_PART_ID;