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Commit 7d1f4126 authored by Igor Babaev's avatar Igor Babaev
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Fixed LP bug #899777. 

KEYUSE elements for a possible hash join key are not sorted by field
numbers of the second table T of the hash join operation. Besides
some of these KEYUSE elements cannot be used to build any key as their
key expressions depend on the tables that are planned to be accessed
after the table T. 
The code before the patch did not take this into account and, as a result,
execition of a query the employing block-based hash join algorithm could
cause a crash or return a wrong result set.
parent b5a05df6
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Showing with 135 additions and 14 deletions
mysql-test/r/join_cache.result
View file @ 7d1f4126
......@@ -5179,4 +5179,51 @@ a b
SET SESSION join_cache_level = DEFAULT;
SET optimizer_switch=@tmp887479_optimizer_switch;
DROP TABLE t1,t2;
#
# Bug #899777: join_cache_level=4 + semijoin=on
#
CREATE TABLE t1 (a int, b int, c int, UNIQUE INDEX idx (a));
INSERT INTO t1 VALUES (1,8,6), (2,2,8);
CREATE TABLE t2 (a int, b int, c int, UNIQUE INDEX idx (a));
INSERT INTO t2 VALUES (1,8,6), (2,2,8);
CREATE TABLE t3 (a int, b int, c int, UNIQUE INDEX idx (a));
INSERT INTO t3 VALUES (1,8,6), (2,2,8);
CREATE TABLE t4 (a int, b int, c int, UNIQUE INDEX idx (a));
INSERT INTO t4 VALUES (1,8,6), (2,2,8);
SET @tmp_optimizer_switch=@@optimizer_switch;
SET SESSION optimizer_switch='semijoin=on';
SET SESSION optimizer_switch='semijoin_with_cache=on';
SET SESSION join_cache_level=1;
EXPLAIN
SELECT t1.* FROM t1,t2
WHERE (t1.b,t2.b) IN (SELECT t3.b,t4.b FROM t3,t4 WHERE t4.c=t3.b)
AND t1.a = 1;
id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY t1 const idx idx 5 const 1
1 PRIMARY t2 ALL NULL NULL NULL NULL 2
1 PRIMARY t3 ALL NULL NULL NULL NULL 2 Using where; Start temporary; Using join buffer (flat, BNL join)
1 PRIMARY t4 ALL NULL NULL NULL NULL 2 Using where; End temporary; Using join buffer (flat, BNL join)
SELECT t1.* FROM t1,t2
WHERE (t1.b,t2.b) IN (SELECT t3.b,t4.b FROM t3,t4 WHERE t4.c=t3.b)
AND t1.a = 1;
a b c
1 8 6
SET SESSION join_cache_level=4;
EXPLAIN
SELECT t1.* FROM t1,t2
WHERE (t1.b,t2.b) IN (SELECT t3.b,t4.b FROM t3,t4 WHERE t4.c=t3.b)
AND t1.a = 1;
id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY t1 const idx idx 5 const 1
1 PRIMARY t2 ALL NULL NULL NULL NULL 2 Using where
1 PRIMARY t3 hash_ALL NULL #hash#$hj 5 const 2 Using where; Start temporary; Using join buffer (flat, BNLH join)
1 PRIMARY t4 hash_ALL NULL #hash#$hj 10 const,test.t2.b 2 Using where; End temporary; Using join buffer (incremental, BNLH join)
SELECT t1.* FROM t1,t2
WHERE (t1.b,t2.b) IN (SELECT t3.b,t4.b FROM t3,t4 WHERE t4.c=t3.b)
AND t1.a = 1;
a b c
1 8 6
SET SESSION join_cache_level = DEFAULT;
SET optimizer_switch=@tmp_optimizer_switch;
DROP TABLE t1,t2,t3,t4;
set @@optimizer_switch=@save_optimizer_switch;
mysql-test/t/join_cache.test
View file @ 7d1f4126
......@@ -3254,5 +3254,45 @@ SET optimizer_switch=@tmp887479_optimizer_switch;
DROP TABLE t1,t2;
--echo #
--echo # Bug #899777: join_cache_level=4 + semijoin=on
--echo #
CREATE TABLE t1 (a int, b int, c int, UNIQUE INDEX idx (a));
INSERT INTO t1 VALUES (1,8,6), (2,2,8);
CREATE TABLE t2 (a int, b int, c int, UNIQUE INDEX idx (a));
INSERT INTO t2 VALUES (1,8,6), (2,2,8);
CREATE TABLE t3 (a int, b int, c int, UNIQUE INDEX idx (a));
INSERT INTO t3 VALUES (1,8,6), (2,2,8);
CREATE TABLE t4 (a int, b int, c int, UNIQUE INDEX idx (a));
INSERT INTO t4 VALUES (1,8,6), (2,2,8);
SET @tmp_optimizer_switch=@@optimizer_switch;
SET SESSION optimizer_switch='semijoin=on';
SET SESSION optimizer_switch='semijoin_with_cache=on';
SET SESSION join_cache_level=1;
EXPLAIN
SELECT t1.* FROM t1,t2
WHERE (t1.b,t2.b) IN (SELECT t3.b,t4.b FROM t3,t4 WHERE t4.c=t3.b)
AND t1.a = 1;
SELECT t1.* FROM t1,t2
WHERE (t1.b,t2.b) IN (SELECT t3.b,t4.b FROM t3,t4 WHERE t4.c=t3.b)
AND t1.a = 1;
SET SESSION join_cache_level=4;
EXPLAIN
SELECT t1.* FROM t1,t2
WHERE (t1.b,t2.b) IN (SELECT t3.b,t4.b FROM t3,t4 WHERE t4.c=t3.b)
AND t1.a = 1;
SELECT t1.* FROM t1,t2
WHERE (t1.b,t2.b) IN (SELECT t3.b,t4.b FROM t3,t4 WHERE t4.c=t3.b)
AND t1.a = 1;
SET SESSION join_cache_level = DEFAULT;
SET optimizer_switch=@tmp_optimizer_switch;
DROP TABLE t1,t2,t3,t4;
# this must be the last command in the file
set @@optimizer_switch=@save_optimizer_switch;
sql/sql_select.cc
View file @ 7d1f4126
......@@ -7183,10 +7183,26 @@ static bool create_hj_key_for_table(JOIN *join, JOIN_TAB *join_tab,
do
{
if (!(~used_tables & keyuse->used_tables) &&
(first_keyuse || keyuse->keypart != (keyuse-1)->keypart))
if (!(~used_tables & keyuse->used_tables))
{
if (first_keyuse)
{
key_parts++;
first_keyuse= FALSE;
}
else
{
KEYUSE *curr= org_keyuse;
for( ; curr < keyuse; curr++)
{
if (curr->keypart == keyuse->keypart &&
!(~used_tables & curr->used_tables))
break;
}
if (curr == keyuse)
key_parts++;
}
}
keyuse++;
} while (keyuse->table == table && keyuse->is_for_hash_join());
if (!key_parts)
......@@ -7211,15 +7227,31 @@ static bool create_hj_key_for_table(JOIN *join, JOIN_TAB *join_tab,
keyuse= org_keyuse;
do
{
if (!(~used_tables & keyuse->used_tables) &&
(first_keyuse || keyuse->keypart != (keyuse-1)->keypart))
if (!(~used_tables & keyuse->used_tables))
{
bool add_key_part= TRUE;
if (!first_keyuse)
{
for(KEYUSE *curr= org_keyuse; curr < keyuse; curr++)
{
if (curr->keypart == keyuse->keypart &&
!(~used_tables & curr->used_tables))
{
keyuse->keypart= NO_KEYPART;
add_key_part= FALSE;
break;
}
}
}
if (add_key_part)
{
Field *field= table->field[keyuse->keypart];
uint fieldnr= keyuse->keypart+1;
table->create_key_part_by_field(keyinfo, key_part_info, field, fieldnr);
first_keyuse= FALSE;
key_part_info++;
}
}
first_keyuse= FALSE;
keyuse++;
} while (keyuse->table == table && keyuse->is_for_hash_join());
......@@ -7302,8 +7334,7 @@ static bool create_ref_for_key(JOIN *join, JOIN_TAB *j,
{
if (are_tables_local(j, keyuse->val->used_tables()))
{
if ((is_hash_join_key_no(key) &&
(keyparts == 0 || keyuse->keypart != (keyuse-1)->keypart)) ||
if ((is_hash_join_key_no(key) && keyuse->keypart != NO_KEYPART) ||
(!is_hash_join_key_no(key) && keyparts == keyuse->keypart &&
!(found_part_ref_or_null & keyuse->optimize)))
{
......@@ -7357,6 +7388,7 @@ static bool create_ref_for_key(JOIN *join, JOIN_TAB *j,
for (i=0 ; i < keyparts ; keyuse++,i++)
{
while (((~used_tables) & keyuse->used_tables) ||
keyuse->keypart == NO_KEYPART ||
(keyuse->keypart !=
(is_hash_join_key_no(key) ?
keyinfo->key_part[i].field->field_index : i)) ||
......
sql/sql_select.h
View file @ 7d1f4126
......@@ -77,6 +77,8 @@ typedef struct keyuse_t {
bool is_for_hash_join() { return is_hash_join_key_no(key); }
} KEYUSE;
#define NO_KEYPART ((uint)(-1))
class store_key;
const int NO_REF_PART= uint(-1);
......
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