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| author | Sergey Petrunya <psergey@askmonty.org> | 2013-07-25 22:42:26 +0400 |
|---|---|---|
| committer | Sergey Petrunya <psergey@askmonty.org> | 2013-07-25 22:42:26 +0400 |
| commit | 9a780a59d53a905d8acf67e51cba5f1492e706b6 (patch) | |
| tree | 6b383db88c8c731c2e8d2000593e843113ad7bc6 /storage/maria | |
| parent | 9e13011efb137728e14a89d936616a14ebee8f59 (diff) | |
| download | mariadb-git-9a780a59d53a905d8acf67e51cba5f1492e706b6.tar.gz | |
MDEV-4687: impossible where with < operation, but =-5 return one row
- Let _ma_record_pos() set SEARCH_PART_KEY when doing a search on
a prefix of a [unique] key. Otherwise, _ma_search_pos() would
find the first key equal to search key, and assume it is also
the last one, which will make a wrong estimate of key's position.
A wrong key position may cause min_pos > max_pos and records_in_range()
will return 0, which will make the optimizer think it's an impossible
range while in fact it is not.
Diffstat (limited to 'storage/maria')
| -rw-r--r-- | storage/maria/ma_range.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/storage/maria/ma_range.c b/storage/maria/ma_range.c index bb72c10bba7..2a01359f1a1 100644 --- a/storage/maria/ma_range.c +++ b/storage/maria/ma_range.c @@ -144,6 +144,10 @@ static ha_rows _ma_record_pos(MARIA_HA *info, const uchar *key_data, (HA_KEYSEG**) 0); DBUG_EXECUTE("key", _ma_print_key(DBUG_FILE, &key);); nextflag=maria_read_vec[search_flag]; + + /* Indicate if we're doing a search on a key prefix */ + if (((((key_part_map)1) << key.keyinfo->keysegs) - 1) != keypart_map) + nextflag |= SEARCH_PART_KEY; /* my_handler.c:ha_compare_text() has a flag 'skip_end_space'. |