From 3f9e14f97886e9465b69029b44ec9683c8041343 Mon Sep 17 00:00:00 2001
From: Igor Babaev <igor@askmonty.org>
Date: Sun, 16 Oct 2011 13:23:57 -0700
Subject: [PATCH] Fixed LP bug #874006. This bug manifested itself with queries
containing non-correlated IN subqueries over materialized views/derived
tables. The bug happened because the code of the function
generate_derived_keys did not take into account that the function could be
called twice when the optimizer was deciding whether in-exist transformation
should be applied.
---
mysql-test/r/derived_view.result | 44 +++++++++++++++++++++++++++++++-
mysql-test/t/derived_view.test | 37 +++++++++++++++++++++++++++
sql/sql_select.cc | 36 ++++++++++++++++++--------
sql/table.cc | 13 ++++++----
4 files changed, 113 insertions(+), 17 deletions(-)
diff --git a/mysql-test/r/derived_view.result b/mysql-test/r/derived_view.result
index ceb63ddc967..96fcde64b57 100644
--- a/mysql-test/r/derived_view.result
+++ b/mysql-test/r/derived_view.result
@@ -781,7 +781,7 @@ SELECT * FROM t3
WHERE t3.a IN (SELECT v1.a FROM v1, t2 WHERE t2.a = v1.b);
id select_type table type possible_keys key key_len ref rows filtered Extra
1 PRIMARY t3 ALL NULL NULL NULL NULL 4 100.00 Using where
-2 DEPENDENT SUBQUERY <derived3> ref key0 key0 5 func 2 100.00
+2 DEPENDENT SUBQUERY <derived3> ref key1 key1 5 func 2 100.00
2 DEPENDENT SUBQUERY t2 ALL NULL NULL NULL NULL 3 100.00 Using where; Using join buffer (flat, BNL join)
3 DERIVED t1 ALL NULL NULL NULL NULL 3 100.00 Using temporary; Using filesort
Warnings:
@@ -1462,4 +1462,46 @@ b a
9 2
7 2
DROP TABLE t1,t2,t3;
+#
+# LP bug #874006: materialized view used in IN subquery
+#
+CREATE TABLE t3 (a int NOT NULL, b varchar(1), c varchar(1));
+INSERT INTO t3 VALUES (19,NULL,NULL), (20,'r','r');
+CREATE TABLE t1 (a int, b varchar(1) , c varchar(1));
+INSERT INTO t1 VALUES (1,NULL,NULL), (5,'r','r'), (7,'y','y');
+CREATE TABLE t2 (a int NOT NULL , b int, c varchar(1));
+INSERT INTO t2 VALUES (4,3,'r');
+CREATE ALGORITHM=TEMPTABLE VIEW v1 AS SELECT * FROM t1;
+SET SESSION optimizer_switch='derived_with_keys=off';
+EXPLAIN
+SELECT * FROM t3
+WHERE t3.b IN (SELECT v1.b FROM v1, t2
+WHERE t2.c = v1.c AND t2.c = v1.b AND v1.b = t3.c);
+id select_type table type possible_keys key key_len ref rows Extra
+1 PRIMARY t3 ALL NULL NULL NULL NULL 2 Using where
+2 DEPENDENT SUBQUERY t2 system NULL NULL NULL NULL 1
+2 DEPENDENT SUBQUERY <derived3> ALL NULL NULL NULL NULL 3 Using where
+3 DERIVED t1 ALL NULL NULL NULL NULL 3
+SELECT * FROM t3
+WHERE t3.b IN (SELECT v1.b FROM v1, t2
+WHERE t2.c = v1.c AND t2.c = v1.b AND v1.b = t3.c);
+a b c
+20 r r
+SET SESSION optimizer_switch='derived_with_keys=on';
+EXPLAIN
+SELECT * FROM t3
+WHERE t3.b IN (SELECT v1.b FROM v1, t2
+WHERE t2.c = v1.c AND t2.c = v1.b AND v1.b = t3.c);
+id select_type table type possible_keys key key_len ref rows Extra
+1 PRIMARY t3 ALL NULL NULL NULL NULL 2 Using where
+2 DEPENDENT SUBQUERY t2 system NULL NULL NULL NULL 1
+2 DEPENDENT SUBQUERY <derived3> ref key1 key1 10 const,const 0 Using where
+3 DERIVED t1 ALL NULL NULL NULL NULL 3
+SELECT * FROM t3
+WHERE t3.b IN (SELECT v1.b FROM v1, t2
+WHERE t2.c = v1.c AND t2.c = v1.b AND v1.b = t3.c);
+a b c
+20 r r
+DROP VIEW v1;
+DROP TABLE t1,t2,t3;
set optimizer_switch=@exit_optimizer_switch;
diff --git a/mysql-test/t/derived_view.test b/mysql-test/t/derived_view.test
index 9f7e24481a0..044f6a1704f 100644
--- a/mysql-test/t/derived_view.test
+++ b/mysql-test/t/derived_view.test
@@ -910,5 +910,42 @@ SELECT * FROM t1 , t2
DROP TABLE t1,t2,t3;
+--echo #
+--echo # LP bug #874006: materialized view used in IN subquery
+--echo #
+
+CREATE TABLE t3 (a int NOT NULL, b varchar(1), c varchar(1));
+INSERT INTO t3 VALUES (19,NULL,NULL), (20,'r','r');
+
+CREATE TABLE t1 (a int, b varchar(1) , c varchar(1));
+INSERT INTO t1 VALUES (1,NULL,NULL), (5,'r','r'), (7,'y','y');
+
+CREATE TABLE t2 (a int NOT NULL , b int, c varchar(1));
+INSERT INTO t2 VALUES (4,3,'r');
+
+CREATE ALGORITHM=TEMPTABLE VIEW v1 AS SELECT * FROM t1;
+
+SET SESSION optimizer_switch='derived_with_keys=off';
+EXPLAIN
+SELECT * FROM t3
+ WHERE t3.b IN (SELECT v1.b FROM v1, t2
+ WHERE t2.c = v1.c AND t2.c = v1.b AND v1.b = t3.c);
+SELECT * FROM t3
+ WHERE t3.b IN (SELECT v1.b FROM v1, t2
+ WHERE t2.c = v1.c AND t2.c = v1.b AND v1.b = t3.c);
+
+SET SESSION optimizer_switch='derived_with_keys=on';
+EXPLAIN
+SELECT * FROM t3
+ WHERE t3.b IN (SELECT v1.b FROM v1, t2
+ WHERE t2.c = v1.c AND t2.c = v1.b AND v1.b = t3.c);
+SELECT * FROM t3
+ WHERE t3.b IN (SELECT v1.b FROM v1, t2
+ WHERE t2.c = v1.c AND t2.c = v1.b AND v1.b = t3.c);
+
+DROP VIEW v1;
+DROP TABLE t1,t2,t3;
+
+
# The following command must be the last one the file
set optimizer_switch=@exit_optimizer_switch;
diff --git a/sql/sql_select.cc b/sql/sql_select.cc
index 61981f87c0a..24778ef6a98 100644
--- a/sql/sql_select.cc
+++ b/sql/sql_select.cc
@@ -8413,17 +8413,17 @@ bool generate_derived_keys_for_table(KEYUSE *keyuse, uint count, uint keys)
TABLE *table= keyuse->table;
if (table->alloc_keys(keys))
return TRUE;
- uint keyno= 0;
+ uint key_count= 0;
KEYUSE *first_keyuse= keyuse;
uint prev_part= keyuse->keypart;
uint parts= 0;
uint i= 0;
- for ( ; i < count && keyno < keys; )
+ for ( ; i < count && key_count < keys; )
{
do
{
- keyuse->key= keyno;
+ keyuse->key= table->s->keys;
keyuse->keypart_map= (key_part_map) (1 << parts);
keyuse++;
i++;
@@ -8437,14 +8437,14 @@ bool generate_derived_keys_for_table(KEYUSE *keyuse, uint count, uint keys)
}
else
{
- if (table->add_tmp_key(keyno, parts,
+ if (table->add_tmp_key(table->s->keys, parts,
get_next_field_for_derived_key,
(uchar *) &first_keyuse,
FALSE))
return TRUE;
- table->reginfo.join_tab->keys.set_bit(keyno);
+ table->reginfo.join_tab->keys.set_bit(table->s->keys);
first_keyuse= keyuse;
- keyno++;
+ key_count++;
parts= 0;
prev_part= keyuse->keypart;
}
@@ -8471,12 +8471,23 @@ bool generate_derived_keys(DYNAMIC_ARRAY *keyuse_array)
TABLE_LIST *derived= NULL;
if (keyuse->table != prev_table)
derived= keyuse->table->pos_in_table_list;
- while (derived && derived->is_materialized_derived() &&
- keyuse->key == MAX_KEY)
+ while (derived && derived->is_materialized_derived())
{
if (keyuse->table != prev_table)
{
prev_table= keyuse->table;
+ while (keyuse->table == prev_table && keyuse->key != MAX_KEY)
+ {
+ keyuse++;
+ i++;
+ }
+ if (keyuse->table != prev_table)
+ {
+ keyuse--;
+ i--;
+ derived= NULL;
+ continue;
+ }
first_table_keyuse= keyuse;
last_used_tables= keyuse->used_tables;
count= 0;
@@ -8489,11 +8500,13 @@ bool generate_derived_keys(DYNAMIC_ARRAY *keyuse_array)
}
count++;
keyuse++;
+ i++;
if (keyuse->table != prev_table)
{
if (generate_derived_keys_for_table(first_table_keyuse, count, ++keys))
return TRUE;
keyuse--;
+ i--;
derived= NULL;
}
}
@@ -8524,12 +8537,13 @@ void JOIN::drop_unused_derived_keys()
TABLE *table=tab->table;
if (!table)
continue;
- if (!table->pos_in_table_list->is_materialized_derived() ||
- table->max_keys <= 1)
+ if (!table->pos_in_table_list->is_materialized_derived())
continue;
- table->use_index(tab->ref.key);
+ if (table->max_keys > 1)
+ table->use_index(tab->ref.key);
if (table->s->keys)
tab->ref.key= 0;
+ tab->keys= (key_map) (table->s->keys ? 1 : 0);
}
}
diff --git a/sql/table.cc b/sql/table.cc
index d54135b5620..382de16b81c 100644
--- a/sql/table.cc
+++ b/sql/table.cc
@@ -5220,10 +5220,11 @@ void st_table::mark_virtual_columns_for_write(bool insert_fl)
@brief
Allocate space for keys
- @param key_count number of keys to allocate
+ @param key_count number of keys to allocate additionally
@details
- The function allocates memory to fit 'key_count' keys for this table.
+ The function allocates memory to fit additionally 'key_count' keys
+ for this table.
@return FALSE space was successfully allocated
@return TRUE an error occur
@@ -5231,9 +5232,11 @@ void st_table::mark_virtual_columns_for_write(bool insert_fl)
bool TABLE::alloc_keys(uint key_count)
{
- key_info= s->key_info= (KEY*) alloc_root(&mem_root, sizeof(KEY)*key_count);
- s->keys= 0;
- max_keys= key_count;
+ key_info= (KEY*) alloc_root(&mem_root, sizeof(KEY)*(s->keys+key_count));
+ if (s->keys)
+ memmove(key_info, s->key_info, sizeof(KEY)*s->keys);
+ s->key_info= key_info;
+ max_keys= s->keys+key_count;
return !(key_info);
}
--
2.30.9