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author | Martin Hansson <martin.hansson@sun.com> | 2010-06-24 15:21:23 +0200 |
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committer | Martin Hansson <martin.hansson@sun.com> | 2010-06-24 15:21:23 +0200 |
commit | dac59fa9c3dab835872b9e9581ed5414d113e09e (patch) | |
tree | 2021a4b16d7dd8402d35c567685bc77fcdd32115 /mysql-test/r/error_simulation.result | |
parent | a08780df9875acbdaec98d7e985a823a4202fad0 (diff) | |
download | mariadb-git-dac59fa9c3dab835872b9e9581ed5414d113e09e.tar.gz |
Bug#41660: Sort-index_merge for non-first join table may
require O(#scans) memory
When an index merge operation was restarted, it would
re-allocate the Unique object controlling the duplicate row
ID elimination. Fixed by making the Unique object a member
of QUICK_INDEX_MERGE_SELECT and thus reusing it throughout
the lifetime of this object.
Diffstat (limited to 'mysql-test/r/error_simulation.result')
-rw-r--r-- | mysql-test/r/error_simulation.result | 35 |
1 files changed, 35 insertions, 0 deletions
diff --git a/mysql-test/r/error_simulation.result b/mysql-test/r/error_simulation.result index fc58687cc86..b6b79cb596b 100644 --- a/mysql-test/r/error_simulation.result +++ b/mysql-test/r/error_simulation.result @@ -48,5 +48,40 @@ Got one of the listed errors SET SESSION debug=DEFAULT; DROP TABLE t1; # +# Bug#41660: Sort-index_merge for non-first join table may require +# O(#scans) memory +# +CREATE TABLE t1 (a INT); +INSERT INTO t1 VALUES (0), (1), (2), (3), (4), (5), (6), (7), (8), (9); +CREATE TABLE t2 (a INT, b INT, filler CHAR(100), KEY(a), KEY(b)); +INSERT INTO t2 SELECT 1000, 1000, 'filler' FROM t1 A, t1 B, t1 C; +INSERT INTO t2 VALUES (1, 1, 'data'); +# the example query uses LEFT JOIN only for the sake of being able to +# demonstrate the issue with a very small dataset. (left outer join +# disables the use of join buffering, so we get the second table +# re-scanned for every record in the outer table. if we used inner join, +# we would need to have thousands of records and/or more columns in both +# tables so that the join buffer is filled and re-scans are triggered). +SET SESSION debug = '+d,only_one_Unique_may_be_created'; +EXPLAIN +SELECT * FROM t1 LEFT JOIN t2 ON ( t2.a < 10 OR t2.b < 10 ); +id select_type table type possible_keys key key_len ref rows Extra +x x x x x x x x x +x x x x x x x x x Using sort_union(a,b); Using where +SELECT * FROM t1 LEFT JOIN t2 ON ( t2.a < 10 OR t2.b < 10 ); +a a b filler +0 1 1 data +1 1 1 data +2 1 1 data +3 1 1 data +4 1 1 data +5 1 1 data +6 1 1 data +7 1 1 data +8 1 1 data +9 1 1 data +SET SESSION debug = DEFAULT; +DROP TABLE t1, t2; +# # End of 5.1 tests # |