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| author | Sergei Petrunia <psergey@askmonty.org> | 2016-07-05 16:53:03 +0300 |
|---|---|---|
| committer | Sergei Petrunia <psergey@askmonty.org> | 2016-07-05 16:55:11 +0300 |
| commit | 95c286cedf4b9330240a0a91a9fc3e58a17782b9 (patch) | |
| tree | 7ec297064b2266b58e8daf500a0ea9506d067298 /mysql-test/r/order_by.result | |
| parent | d1b25890745a140446e4bdd5fd4f489ce1f76fae (diff) | |
| download | mariadb-git-95c286cedf4b9330240a0a91a9fc3e58a17782b9.tar.gz | |
MDEV-10324: Server crash in get_sel_arg_for_keypart or Assertion
The crash was caused by this problem:
get_best_group_min_max() tries to construct query plans for keys that
are not processed by the range optimizer. This wasn't a problem as long
as SEL_TREE::keys was an array of MAX_KEY elements.
However, now it is a Mem_root_array and only has elements for the used
keys, and get_best_group_min_max attempts to address beyond the end of
the array.
The obvious way to fix the crash was to port (and improve) a part of
96fcfcbd7b5120e8f64fd45985001eca8d36fbfb from mysql-5.7. This makes
get_best_group_min_max not to consider indexes that Mem_root_arrays
have no element for.
After that, I got non-sensical query plans (see MDEV-10325 for details).
Fixed that by making get_best_group_min_max to check if the index is in
table->keys_in_use_for_group_by bitmap.
Diffstat (limited to 'mysql-test/r/order_by.result')
| -rw-r--r-- | mysql-test/r/order_by.result | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/mysql-test/r/order_by.result b/mysql-test/r/order_by.result index 03e7c48951a..d108bce5eb1 100644 --- a/mysql-test/r/order_by.result +++ b/mysql-test/r/order_by.result @@ -1163,7 +1163,7 @@ INSERT INTO t1 SELECT a +32, b +32 FROM t1; INSERT INTO t1 SELECT a +64, b +64 FROM t1; EXPLAIN SELECT a FROM t1 IGNORE INDEX FOR GROUP BY (a, ab) GROUP BY a; id select_type table type possible_keys key key_len ref rows Extra -1 SIMPLE t1 range NULL ab 4 NULL 10 Using index for group-by +1 SIMPLE t1 index NULL PRIMARY 4 NULL 128 Using index SELECT a FROM t1 IGNORE INDEX FOR GROUP BY (a, ab) GROUP BY a; a 1 |