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ORDER BY optimization

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Fixed new bug when reading field types


client/mysql.cc:
  Fixed output for -T
libmysql/libmysql.c:
  Filled missing fields in new MYSQL_FIELD structure
  Fixed new bug when reading field types
mysql-test/r/order_by.result:
  Result after new order by optimization
sql/opt_range.cc:
  New ORDER BY optimization
sql/opt_range.h:
  New ORDER BY optimization
sql/set_var.cc:
  Speed optimization
sql/sql_select.cc:
  New ORDER BY optimization
  
  This alllows MySQL to change a ref/range index from (a,b) to (a,c) when 'b' was not used to find rows and one did
  ORDER BY a,c or ORDER BY c
This commit is contained in:
unknown
2003-05-27 18:40:37 +03:00
parent 1540912eca
commit ef6d3a8060
7 changed files with 40 additions and 20 deletions
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mysql-test/r/order_by.result
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@ -557,7 +557,7 @@ KEY StringField (FieldKey,StringVal(32))
INSERT INTO t1 VALUES ('0',3,'0'),('0',2,'1'),('0',1,'2'),('1',2,'1'),('1',1,'3'), ('1',0,'2'),('2',3,'0'),('2',2,'1'),('2',1,'2'),('2',3,'0'),('2',2,'1'),('2',1,'2'),('3',2,'1'),('3',1,'2'),('3','3','3');
EXPLAIN SELECT * FROM t1 WHERE FieldKey = '1' ORDER BY LongVal;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 ref FieldKey,LongField,StringField StringField 36 const 3 Using where; Using filesort
1 SIMPLE t1 ref FieldKey,LongField,StringField LongField 36 const 3 Using where
SELECT * FROM t1 WHERE FieldKey = '1' ORDER BY LongVal;
FieldKey LongVal StringVal
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