diff options
Diffstat (limited to 'sql/opt_range.cc')
| -rw-r--r-- | sql/opt_range.cc | 32 |
1 files changed, 29 insertions, 3 deletions
diff --git a/sql/opt_range.cc b/sql/opt_range.cc index 4c1a0db72b7..eedae87719d 100644 --- a/sql/opt_range.cc +++ b/sql/opt_range.cc @@ -321,7 +321,7 @@ static bool get_quick_keys(PARAM *param,QUICK_SELECT *quick,KEY_PART *key, static bool eq_tree(SEL_ARG* a,SEL_ARG *b); static SEL_ARG null_element(SEL_ARG::IMPOSSIBLE); - +static bool null_part_in_key(KEY_PART *key_part, const char *key, uint length); /*************************************************************************** ** Basic functions for SQL_SELECT and QUICK_SELECT @@ -2306,7 +2306,15 @@ get_quick_keys(PARAM *param,QUICK_SELECT *quick,KEY_PART *key, KEY *table_key=quick->head->key_info+quick->index; flag=EQ_RANGE; if (table_key->flags & HA_NOSAME && key->part == table_key->key_parts-1) - flag|= UNIQUE_RANGE; + { + if (!(table_key->flags & HA_NULL_PART_KEY) || + !null_part_in_key(key, + param->min_key, + (uint) (tmp_min_key - param->min_key))) + flag|= UNIQUE_RANGE; + else + flag|= NULL_RANGE; + } } } @@ -2339,7 +2347,7 @@ bool QUICK_SELECT::unique_key_range() if (ranges.elements == 1) { QUICK_RANGE *tmp; - if ((tmp=ranges.head())->flag & EQ_RANGE) + if (((tmp=ranges.head())->flag & (EQ_RANGE | NULL_RANGE)) == EQ_RANGE) { KEY *key=head->key_info+index; return ((key->flags & HA_NOSAME) && @@ -2349,6 +2357,24 @@ bool QUICK_SELECT::unique_key_range() return 0; } + +/* Returns true if any part of the key is NULL */ + +static bool null_part_in_key(KEY_PART *key_part, const char *key, uint length) +{ + for (const char *end=key+length ; + key < end; + key+= key_part++->part_length) + { + if (key_part->null_bit) + { + if (*key++) + return 1; + } + } + return 0; +} + /**************************************************************************** ** Create a QUICK RANGE based on a key ****************************************************************************/ |