Hi Jørgen,
Thanks for the patch. Your fix looks good.
However, when the comment right above your fix, it occurred to me that I
had seen a similar comment somewhere else. I found the same comment in
setup_sj_materialization() and this code also has the exact same bug. (I
think large parts of setup_sj_materialization has been copy-pasted from
subselect_hash_sj_engine::init_permanent()). This bug can be triggered
by a variant of your test case: Remove group by part and turn off
firstmatch.
I think it would be good if you could fix both cases in same bug fix.
If you put the modified test case in subquery_sj.inc, it should cover
both code changes, since subquery_sj_mat_nosj.test will test subquery
materialization, and subquery_sj_mat.test will run without FirstMatch.
And we should probably also create a worklog to get rid of this
copy-pasted code.
--
Øystein
On 10/11/10 11:34 AM, Jorgen Loland wrote:
> #At file:///export/home/jl208045/mysql/mysql-next-mr-opt-backporting-52329/ based on
> revid:tor.didriksen@stripped
>
> 3260 Jorgen Loland 2010-10-11
> Bug#52329: Wrong result: subquery materialization, IN, non-null
> field followed by nullable
>
> Consider a query
>
> SELECT * FROM t1
> WHERE (a1, a2) IN (
> SELECT b1, b2 FROM t2 ...)
>
> When solved using materialized subselect, we check if a record
> from t1 is part of the result set by constructing a key from the
> a1 and a2 values and perform a lookup based on that key. If a1
> and a2 are CHAR(3) with values foo and bar, the KEY is "foobar".
> If a2 is NULLable, the null-bit should be the first bit for this
> field's part of the KEY ("foo<nullbit_a2>bar").
>
> Before, the null-bit pointer for each key field wrongly pointed
> to the first bit of the KEY instead of the first bit of the key
> part. Thus, when setting the null bit for a2 above, the first bit
> of a1 was wrongly updated: "0oo bar" ('f' in foo replaced
> with null-bit of a2, and the null-bit of a2 not set)
>
> This patch sets the null-pointer for each key part to the first
> bit of that field's part of KEY, not the first bit of KEY.
>
> The bug was masked if the first field was NOT NULL.
> @ mysql-test/include/subquery_mat.inc
> Added test for BUG#52329
> @ mysql-test/r/subquery_mat.result
> Added test for BUG#52329
> @ mysql-test/r/subquery_mat_all.result
> Added test for BUG#52329
> @ mysql-test/r/subquery_mat_none.result
> Added test for BUG#52329
> @ sql/item_subselect.cc
> subselect_hash_sj_engine::init_permanent:
> Make the null-pointer for each key part point to the first
> bit of that field's part of KEY, not the first bit of KEY.
>
> modified:
> mysql-test/include/subquery_mat.inc
> mysql-test/r/subquery_mat.result
> mysql-test/r/subquery_mat_all.result
> mysql-test/r/subquery_mat_none.result
> sql/item_subselect.cc
> === modified file 'mysql-test/include/subquery_mat.inc'
> --- a/mysql-test/include/subquery_mat.inc 2010-09-08 14:39:38 +0000
> +++ b/mysql-test/include/subquery_mat.inc 2010-10-11 09:34:05 +0000
> @@ -815,3 +815,40 @@ DROP TABLE t1, t2;
>
> --echo # End BUG#56367
>
> +--echo #
> +--echo # BUG#52329 - Wrong result: subquery materialization, IN,
> +--echo # non-null field followed by nullable
> +--echo #
> +
> +CREATE TABLE t1 (a1 CHAR(8) NOT NULL, a2 char(8) NOT NULL);
> +
> +CREATE TABLE t2a (b1 char(8), b2 char(8));
> +CREATE TABLE t2b (b1 CHAR(8), b2 char(8) NOT NULL);
> +CREATE TABLE t2c (b1 CHAR(8) NOT NULL, b2 char(8));
> +
> +INSERT INTO t1 VALUES ('1 - 12', '2 - 22');
> +
> +INSERT INTO t2a VALUES ('1 - 11', '2 - 21'),
> + ('1 - 11', '2 - 21'),
> + ('1 - 12', '2 - 22'),
> + ('1 - 12', '2 - 22'),
> + ('1 - 13', '2 - 23');
> +
> +INSERT INTO t2b SELECT * FROM t2a;
> +INSERT INTO t2c SELECT * FROM t2a;
> +
> +SELECT * FROM t1
> +WHERE (a1, a2) IN (
> + SELECT b1, b2 FROM t2a WHERE b1> '0' GROUP BY b1, b2);
> +
> +SELECT * FROM t1
> +WHERE (a1, a2) IN (
> + SELECT b1, b2 FROM t2b WHERE b1> '0' GROUP BY b1, b2);
> +
> +SELECT * FROM t1
> +WHERE (a1, a2) IN (
> + SELECT b1, b2 FROM t2c WHERE b1> '0' GROUP BY b1, b2);
> +
> +DROP TABLE t1,t2a,t2b,t2c;
> +
> +--echo # End BUG#52329
>
> === modified file 'mysql-test/r/subquery_mat.result'
> --- a/mysql-test/r/subquery_mat.result 2010-09-08 14:39:38 +0000
> +++ b/mysql-test/r/subquery_mat.result 2010-10-11 09:34:05 +0000
> @@ -1097,4 +1097,37 @@ SELECT t1.* FROM t1 LEFT JOIN t2 ON t1.a
> a
> DROP TABLE t1, t2;
> # End BUG#56367
> +#
> +# BUG#52329 - Wrong result: subquery materialization, IN,
> +# non-null field followed by nullable
> +#
> +CREATE TABLE t1 (a1 CHAR(8) NOT NULL, a2 char(8) NOT NULL);
> +CREATE TABLE t2a (b1 char(8), b2 char(8));
> +CREATE TABLE t2b (b1 CHAR(8), b2 char(8) NOT NULL);
> +CREATE TABLE t2c (b1 CHAR(8) NOT NULL, b2 char(8));
> +INSERT INTO t1 VALUES ('1 - 12', '2 - 22');
> +INSERT INTO t2a VALUES ('1 - 11', '2 - 21'),
> +('1 - 11', '2 - 21'),
> +('1 - 12', '2 - 22'),
> +('1 - 12', '2 - 22'),
> +('1 - 13', '2 - 23');
> +INSERT INTO t2b SELECT * FROM t2a;
> +INSERT INTO t2c SELECT * FROM t2a;
> +SELECT * FROM t1
> +WHERE (a1, a2) IN (
> +SELECT b1, b2 FROM t2a WHERE b1> '0' GROUP BY b1, b2);
> +a1 a2
> +1 - 12 2 - 22
> +SELECT * FROM t1
> +WHERE (a1, a2) IN (
> +SELECT b1, b2 FROM t2b WHERE b1> '0' GROUP BY b1, b2);
> +a1 a2
> +1 - 12 2 - 22
> +SELECT * FROM t1
> +WHERE (a1, a2) IN (
> +SELECT b1, b2 FROM t2c WHERE b1> '0' GROUP BY b1, b2);
> +a1 a2
> +1 - 12 2 - 22
> +DROP TABLE t1,t2a,t2b,t2c;
> +# End BUG#52329
> set optimizer_switch=default;
>
> === modified file 'mysql-test/r/subquery_mat_all.result'
> --- a/mysql-test/r/subquery_mat_all.result 2010-09-08 14:39:38 +0000
> +++ b/mysql-test/r/subquery_mat_all.result 2010-10-11 09:34:05 +0000
> @@ -1096,4 +1096,37 @@ SELECT t1.* FROM t1 LEFT JOIN t2 ON t1.a
> a
> DROP TABLE t1, t2;
> # End BUG#56367
> +#
> +# BUG#52329 - Wrong result: subquery materialization, IN,
> +# non-null field followed by nullable
> +#
> +CREATE TABLE t1 (a1 CHAR(8) NOT NULL, a2 char(8) NOT NULL);
> +CREATE TABLE t2a (b1 char(8), b2 char(8));
> +CREATE TABLE t2b (b1 CHAR(8), b2 char(8) NOT NULL);
> +CREATE TABLE t2c (b1 CHAR(8) NOT NULL, b2 char(8));
> +INSERT INTO t1 VALUES ('1 - 12', '2 - 22');
> +INSERT INTO t2a VALUES ('1 - 11', '2 - 21'),
> +('1 - 11', '2 - 21'),
> +('1 - 12', '2 - 22'),
> +('1 - 12', '2 - 22'),
> +('1 - 13', '2 - 23');
> +INSERT INTO t2b SELECT * FROM t2a;
> +INSERT INTO t2c SELECT * FROM t2a;
> +SELECT * FROM t1
> +WHERE (a1, a2) IN (
> +SELECT b1, b2 FROM t2a WHERE b1> '0' GROUP BY b1, b2);
> +a1 a2
> +1 - 12 2 - 22
> +SELECT * FROM t1
> +WHERE (a1, a2) IN (
> +SELECT b1, b2 FROM t2b WHERE b1> '0' GROUP BY b1, b2);
> +a1 a2
> +1 - 12 2 - 22
> +SELECT * FROM t1
> +WHERE (a1, a2) IN (
> +SELECT b1, b2 FROM t2c WHERE b1> '0' GROUP BY b1, b2);
> +a1 a2
> +1 - 12 2 - 22
> +DROP TABLE t1,t2a,t2b,t2c;
> +# End BUG#52329
> set optimizer_switch=default;
>
> === modified file 'mysql-test/r/subquery_mat_none.result'
> --- a/mysql-test/r/subquery_mat_none.result 2010-09-08 14:39:38 +0000
> +++ b/mysql-test/r/subquery_mat_none.result 2010-10-11 09:34:05 +0000
> @@ -1096,4 +1096,37 @@ SELECT t1.* FROM t1 LEFT JOIN t2 ON t1.a
> a
> DROP TABLE t1, t2;
> # End BUG#56367
> +#
> +# BUG#52329 - Wrong result: subquery materialization, IN,
> +# non-null field followed by nullable
> +#
> +CREATE TABLE t1 (a1 CHAR(8) NOT NULL, a2 char(8) NOT NULL);
> +CREATE TABLE t2a (b1 char(8), b2 char(8));
> +CREATE TABLE t2b (b1 CHAR(8), b2 char(8) NOT NULL);
> +CREATE TABLE t2c (b1 CHAR(8) NOT NULL, b2 char(8));
> +INSERT INTO t1 VALUES ('1 - 12', '2 - 22');
> +INSERT INTO t2a VALUES ('1 - 11', '2 - 21'),
> +('1 - 11', '2 - 21'),
> +('1 - 12', '2 - 22'),
> +('1 - 12', '2 - 22'),
> +('1 - 13', '2 - 23');
> +INSERT INTO t2b SELECT * FROM t2a;
> +INSERT INTO t2c SELECT * FROM t2a;
> +SELECT * FROM t1
> +WHERE (a1, a2) IN (
> +SELECT b1, b2 FROM t2a WHERE b1> '0' GROUP BY b1, b2);
> +a1 a2
> +1 - 12 2 - 22
> +SELECT * FROM t1
> +WHERE (a1, a2) IN (
> +SELECT b1, b2 FROM t2b WHERE b1> '0' GROUP BY b1, b2);
> +a1 a2
> +1 - 12 2 - 22
> +SELECT * FROM t1
> +WHERE (a1, a2) IN (
> +SELECT b1, b2 FROM t2c WHERE b1> '0' GROUP BY b1, b2);
> +a1 a2
> +1 - 12 2 - 22
> +DROP TABLE t1,t2a,t2b,t2c;
> +# End BUG#52329
> set optimizer_switch=default;
>
> === modified file 'sql/item_subselect.cc'
> --- a/sql/item_subselect.cc 2010-09-28 15:17:29 +0000
> +++ b/sql/item_subselect.cc 2010-10-11 09:34:05 +0000
> @@ -3214,7 +3214,7 @@ bool subselect_hash_sj_engine::init_perm
> use that information instead.
> */
> cur_ref_buff + null_count,
> - null_count ? tab->ref.key_buff : 0,
> + null_count ? cur_ref_buff : 0,
> cur_key_part->length, tab->ref.items[i]);
> cur_ref_buff+= cur_key_part->store_length;
> }
>
>
>
>
>
--
Øystein Grøvlen, Senior Staff Engineer
Sun Microsystems, Database Group
Trondheim, Norway
