Merge mhansson@bk-internal:/home/bk/mysql-5.0-opt (364014e4) · Commits · Software / OSDI20 Artifacts / mariadb

mysql-test/r/func_group.result

+47 −0

Original line number	Diff line number	Diff line
		@@ -1330,4 +1330,51 @@ SELECT a,AVG(DISTINCT b) AS average FROM t1 GROUP BY a HAVING average > 50;
		a average
		1 32768.5000
		DROP TABLE t1;
		CREATE TABLE t1 ( a INT, b INT, KEY(a) );
		INSERT INTO t1 VALUES (NULL, 1), (NULL, 2);
		EXPLAIN SELECT MIN(a), MIN(b) FROM t1;
		id select_type table type possible_keys key key_len ref rows Extra
		1 SIMPLE t1 ALL NULL NULL NULL NULL 2
		SELECT MIN(a), MIN(b) FROM t1;
		MIN(a) MIN(b)
		NULL 1
		CREATE TABLE t2( a INT, b INT, c INT, KEY(a, b) );
		INSERT INTO t2 ( a, b, c ) VALUES ( 1, NULL, 2 ), ( 1, 3, 4 ), ( 1, 4, 4 );
		EXPLAIN SELECT MIN(b), MIN(c) FROM t2 WHERE a = 1;
		id select_type table type possible_keys key key_len ref rows Extra
		1 SIMPLE t2 ref a a 5 const 2 Using where
		SELECT MIN(b), MIN(c) FROM t2 WHERE a = 1;
		MIN(b) MIN(c)
		3 2
		CREATE TABLE t3 (a INT, b INT, c int, KEY(a, b));
		INSERT INTO t3 VALUES (1, NULL, 1), (2, NULL, 2), (2, NULL, 2), (3, NULL, 3);
		EXPLAIN SELECT MIN(a), MIN(b) FROM t3 where a = 2;
		id select_type table type possible_keys key key_len ref rows Extra
		1 SIMPLE NULL NULL NULL NULL NULL NULL NULL Select tables optimized away
		SELECT MIN(a), MIN(b) FROM t3 where a = 2;
		MIN(a) MIN(b)
		2 NULL
		CREATE TABLE t4 (a INT, b INT, c int, KEY(a, b));
		INSERT INTO t4 VALUES (1, 1, 1), (2, NULL, 2), (2, NULL, 2), (3, 1, 3);
		EXPLAIN SELECT MIN(a), MIN(b) FROM t4 where a = 2;
		id select_type table type possible_keys key key_len ref rows Extra
		1 SIMPLE NULL NULL NULL NULL NULL NULL NULL Select tables optimized away
		SELECT MIN(a), MIN(b) FROM t4 where a = 2;
		MIN(a) MIN(b)
		2 NULL
		SELECT MIN(b), min(c) FROM t4 where a = 2;
		MIN(b) min(c)
		NULL 2
		CREATE TABLE t5( a INT, b INT, KEY( a, b) );
		INSERT INTO t5 VALUES( 1, 1 ), ( 1, 2 );
		EXPLAIN SELECT MIN(a), MIN(b) FROM t5 WHERE a = 1;
		id select_type table type possible_keys key key_len ref rows Extra
		1 SIMPLE NULL NULL NULL NULL NULL NULL NULL Select tables optimized away
		SELECT MIN(a), MIN(b) FROM t5 WHERE a = 1;
		MIN(a) MIN(b)
		1 1
		SELECT MIN(a), MIN(b) FROM t5 WHERE a = 1 and b > 1;
		MIN(a) MIN(b)
		1 2
		DROP TABLE t1, t2, t3, t4, t5;
		End of 5.0 tests

mysql-test/t/func_group.test

+34 −0

Original line number	Diff line number	Diff line
		@@ -827,4 +827,38 @@ SELECT a,AVG(DISTINCT b) AS average FROM t1 GROUP BY a HAVING average > 50;

		DROP TABLE t1;

		#
		# Bug #27573: MIN() on an indexed column which is always NULL sets _other_
		# results to NULL
		#
		CREATE TABLE t1 ( a INT, b INT, KEY(a) );
		INSERT INTO t1 VALUES (NULL, 1), (NULL, 2);
		EXPLAIN SELECT MIN(a), MIN(b) FROM t1;
		SELECT MIN(a), MIN(b) FROM t1;

		CREATE TABLE t2( a INT, b INT, c INT, KEY(a, b) );
		INSERT INTO t2 ( a, b, c ) VALUES ( 1, NULL, 2 ), ( 1, 3, 4 ), ( 1, 4, 4 );
		EXPLAIN SELECT MIN(b), MIN(c) FROM t2 WHERE a = 1;
		SELECT MIN(b), MIN(c) FROM t2 WHERE a = 1;

		CREATE TABLE t3 (a INT, b INT, c int, KEY(a, b));
		INSERT INTO t3 VALUES (1, NULL, 1), (2, NULL, 2), (2, NULL, 2), (3, NULL, 3);
		EXPLAIN SELECT MIN(a), MIN(b) FROM t3 where a = 2;
		SELECT MIN(a), MIN(b) FROM t3 where a = 2;

		CREATE TABLE t4 (a INT, b INT, c int, KEY(a, b));
		INSERT INTO t4 VALUES (1, 1, 1), (2, NULL, 2), (2, NULL, 2), (3, 1, 3);
		EXPLAIN SELECT MIN(a), MIN(b) FROM t4 where a = 2;
		SELECT MIN(a), MIN(b) FROM t4 where a = 2;
		SELECT MIN(b), min(c) FROM t4 where a = 2;

		CREATE TABLE t5( a INT, b INT, KEY( a, b) );
		INSERT INTO t5 VALUES( 1, 1 ), ( 1, 2 );
		EXPLAIN SELECT MIN(a), MIN(b) FROM t5 WHERE a = 1;
		SELECT MIN(a), MIN(b) FROM t5 WHERE a = 1;
		SELECT MIN(a), MIN(b) FROM t5 WHERE a = 1 and b > 1;

		DROP TABLE t1, t2, t3, t4, t5;

		###
		--echo End of 5.0 tests

sql/opt_sum.cc

+76 −10

Original line number	Diff line number	Diff line
		@@ -207,11 +207,67 @@ int opt_sum_query(TABLE_LIST tables, List<Item> &all_fields,COND conds)
		if (!ref.key_length)
		error= table->file->index_first(table->record[0]);
		else
		error= table->file->index_read(table->record[0],key_buff,
		{
		/*
		Use index to replace MIN/MAX functions with their values
		according to the following rules:

		1) Insert the minimum non-null values where the WHERE clause still
		matches, or
		2) a NULL value if there are only NULL values for key_part_k.
		3) Fail, producing a row of nulls

		Implementation: Read the smallest value using the search key. If
		the interval is open, read the next value after the search
		key. If read fails, and we're looking for a MIN() value for a
		nullable column, test if there is an exact match for the key.
		*/
		if (!(range_fl & NEAR_MIN))
		/*
		Closed interval: Either The MIN argument is non-nullable, or
		we have a >= predicate for the MIN argument.
		*/
		error= table->file->index_read(table->record[0], ref.key_buff,
		ref.key_length,
		range_fl & NEAR_MIN ?
		HA_READ_AFTER_KEY :
		HA_READ_KEY_OR_NEXT);
		else
		{
		/*
		Open interval: There are two cases:
		1) We have only MIN() and the argument column is nullable, or
		2) there is a > predicate on it, nullability is irrelevant.
		We need to scan the next bigger record first.
		*/
		error= table->file->index_read(table->record[0], ref.key_buff,
		ref.key_length, HA_READ_AFTER_KEY);
		/*
		If the found record is outside the group formed by the search
		prefix, or there is no such record at all, check if all
		records in that group have NULL in the MIN argument
		column. If that is the case return that NULL.

		Check if case 1 from above holds. If it does, we should read
		the skipped tuple.
		*/
		if (ref.key_buff[prefix_len] == 1 &&
		/*
		Last keypart (i.e. the argument to MIN) is set to NULL by
		find_key_for_maxmin only if all other keyparts are bound
		to constants in a conjunction of equalities. Hence, we
		can detect this by checking only if the last keypart is
		NULL.
		*/
		(error == HA_ERR_KEY_NOT_FOUND \|\|
		key_cmp_if_same(table, ref.key_buff, ref.key, prefix_len)))
		{
		DBUG_ASSERT(item_field->field->real_maybe_null());
		error= table->file->index_read(table->record[0], ref.key_buff,
		ref.key_length,
		HA_READ_KEY_EXACT);
		}
		}
		}
		/* Verify that the read tuple indeed matches the search key */
		if (!error && reckey_in_range(0, &ref, item_field->field,
		conds, range_fl, prefix_len))
		error= HA_ERR_KEY_NOT_FOUND;
		@@ -739,14 +795,24 @@ static bool find_key_for_maxmin(bool max_fl, TABLE_REF *ref,
		if (!max_fl && key_part_used == key_part_to_use && part->null_bit)
		{
		/*
		SELECT MIN(key_part2) FROM t1 WHERE key_part1=const
		If key_part2 may be NULL, then we want to find the first row
		that is not null
		The query is on this form:

		SELECT MIN(key_part_k)
		FROM t1
		WHERE key_part_1 = const and ... and key_part_k-1 = const

		If key_part_k is nullable, we want to find the first matching row
		where key_part_k is not null. The key buffer is now {const, ...,
		NULL}. This will be passed to the handler along with a flag
		indicating open interval. If a tuple is read that does not match
		these search criteria, an attempt will be made to read an exact
		match for the key buffer.
		*/
		/* Set the first byte of key_part_k to 1, that means NULL */
		ref->key_buff[ref->key_length]= 1;
		ref->key_length+= part->store_length;
		*range_fl&= ~NO_MIN_RANGE;
		*range_fl\|= NEAR_MIN; // > NULL
		*range_fl\|= NEAR_MIN; // Open interval
		}
		/*
		The following test is false when the key in the key tree is