diff options
Diffstat (limited to 'myisammrg/myrg_queue.c')
| -rw-r--r-- | myisammrg/myrg_queue.c | 20 |
1 files changed, 17 insertions, 3 deletions
diff --git a/myisammrg/myrg_queue.c b/myisammrg/myrg_queue.c index 7172b9f0e2a..2e600a526c0 100644 --- a/myisammrg/myrg_queue.c +++ b/myisammrg/myrg_queue.c @@ -18,12 +18,26 @@ static int queue_key_cmp(void *keyseg, byte *a, byte *b) { - MI_INFO *aa=((MYRG_TABLE *)a)->table; - MI_INFO *bb=((MYRG_TABLE *)b)->table; + MYRG_TABLE *ma= (MYRG_TABLE *)a; + MYRG_TABLE *mb= (MYRG_TABLE *)b; + MI_INFO *aa= ma->table; + MI_INFO *bb= mb->table; uint not_used[2]; int ret= ha_key_cmp((HA_KEYSEG *)keyseg, aa->lastkey, bb->lastkey, USE_WHOLE_KEY, SEARCH_FIND, not_used); - return ret < 0 ? -1 : ret > 0 ? 1 : 0; + if (ret < 0) + return -1; + if (ret > 0) + return 1; + + /* + If index tuples have the same values, let the record with least rowid + value be "smaller", so index scans return records ordered by (keytuple, + rowid). This is used by index_merge access method, grep for ROR in + sql/opt_range.cc for details. + */ + return (ma->file_offset < mb->file_offset)? -1 : (ma->file_offset > + mb->file_offset) ? 1 : 0; } /* queue_key_cmp */ |