diff options
Diffstat (limited to 'sql')
| -rw-r--r-- | sql/sql_select.cc | 23 |
1 files changed, 21 insertions, 2 deletions
diff --git a/sql/sql_select.cc b/sql/sql_select.cc index 5fc97385f15..1b1a35d2584 100644 --- a/sql/sql_select.cc +++ b/sql/sql_select.cc @@ -2409,6 +2409,7 @@ add_key_field(KEY_FIELD **key_fields,uint and_level, Item_func *cond, !field->table->maybe_null || field->null_ptr) return; // Not a key. Skip it exists_optimize= KEY_OPTIMIZE_EXISTS; + DBUG_ASSERT(num_values == 1); } else { @@ -2460,7 +2461,26 @@ add_key_field(KEY_FIELD **key_fields,uint and_level, Item_func *cond, eq_func is NEVER true when num_values > 1 */ if (!eq_func) - return; + { + /* + Additional optimization: if we're processing + "t.key BETWEEN c1 AND c1" then proceed as if we were processing + "t.key = c1". + TODO: This is a very limited fix. A more generic fix is possible. + There are 2 options: + A) Make equality propagation code be able to handle BETWEEN + (including cases like t1.key BETWEEN t2.key AND t3.key) + B) Make range optimizer to infer additional "t.key = c" equalities + and use them in equality propagation process (see details in + OptimizerKBAndTodo) + */ + if ((cond->functype() == Item_func::BETWEEN) && + value[0]->eq(value[1], field->binary())) + eq_func= TRUE; + else + return; + } + if (field->result_type() == STRING_RESULT) { if ((*value)->result_type() != STRING_RESULT) @@ -2487,7 +2507,6 @@ add_key_field(KEY_FIELD **key_fields,uint and_level, Item_func *cond, } } } - DBUG_ASSERT(num_values == 1); /* For the moment eq_func is always true. This slot is reserved for future extensions where we want to remembers other things than just eq comparisons |