diff options
Diffstat (limited to 'innobase')
| -rw-r--r-- | innobase/row/row0sel.c | 27 |
1 files changed, 17 insertions, 10 deletions
diff --git a/innobase/row/row0sel.c b/innobase/row/row0sel.c index c657a03bd38..a43faaf8096 100644 --- a/innobase/row/row0sel.c +++ b/innobase/row/row0sel.c @@ -3686,16 +3686,23 @@ rec_loop: } } - /* If a constant search tuple is found directly from - the cluster index we lock only a record. - For example: WHERE a >= 100, where a is primary key */ - - if(index == clust_index && - match_mode == ROW_SEL_OPEN_CURSOR && - mode == PAGE_CUR_GE && - dtuple_get_n_fields_cmp(search_tuple) - == dict_index_get_n_unique(index) && - !cmp_dtuple_rec(search_tuple, rec, offsets)) { + /* If we are doing a 'greater or equal than a primary key + value' search from a clustered index, and we find a record + that has that exact primary key value, then there is no need + to lock the gap before the record, because no insert in the + gap can be in our search range. That is, no phantom row can + appear that way. + + An example: if col1 is the primary key, the search is WHERE + col1 >= 100, and we find a record where col1 = 100, then no + need to lock the gap before that record. */ + + if (index == clust_index + && mode == PAGE_CUR_GE + && direction == 0 + && dtuple_get_n_fields_cmp(search_tuple) + == dict_index_get_n_unique(index) + && 0 == cmp_dtuple_rec(search_tuple, rec, offsets)) { lock_type = LOCK_REC_NOT_GAP; } |