Commit 42829c61 authored by unknown's avatar unknown

Bug#4692 - DISABLE/ENABLE KEYS waste a space

Disabling and enabling indexes on a non-empty table grows the
index file.

Disabling indexes just sets a flag per non-unique index and does not
free the index blocks of the affected indexes. Re-enabling indexes
creates new indexes with new blocks. The old blocks remain unused
in the index file.

Fixed by dropping and re-creating all indexes if non-empty disabled
indexes exist when enabling indexes. Dropping all indexes resets
the internal end-of-file marker to the end of the index file header.
It also clears the root block pointers of every index and clears the
deleted blocks chains. This way all blocks are declared as free.


myisam/mi_check.c:
  Bug#4692 - DISABLE/ENABLE KEYS waste a space
  Added function mi_drop_all_indexes() to support drop of all indexes
  in case we want to re-enable non-empty disabled indexes.
  Changed mi_repair(), mi_repair_by_sort(), and mi_repair_parallel()
  to use the new function instead of duplicate drop index code.
mysql-test/r/myisam.result:
  Bug#4692 - DISABLE/ENABLE KEYS waste a space
  Added test result.
mysql-test/t/myisam.test:
  Bug#4692 - DISABLE/ENABLE KEYS waste a space
  Added test.
parent 6f12c924
This diff is collapsed.
...@@ -1806,4 +1806,29 @@ SELECT a FROM t1 FORCE INDEX (inx) WHERE a=1; ...@@ -1806,4 +1806,29 @@ SELECT a FROM t1 FORCE INDEX (inx) WHERE a=1;
a a
1 1
DROP TABLE t1; DROP TABLE t1;
CREATE TABLE t1 (c1 INT, c2 INT, UNIQUE INDEX (c1), INDEX (c2)) ENGINE=MYISAM;
SHOW TABLE STATUS LIKE 't1';
Name Engine Version Row_format Rows Avg_row_length Data_length Max_data_length Index_length Data_free Auto_increment Create_time Update_time Check_time Collation Checksum Create_options Comment
t1 MyISAM 10 Fixed 0 # # # 1024 # # # # # # #
INSERT INTO t1 VALUES (1,1);
SHOW TABLE STATUS LIKE 't1';
Name Engine Version Row_format Rows Avg_row_length Data_length Max_data_length Index_length Data_free Auto_increment Create_time Update_time Check_time Collation Checksum Create_options Comment
t1 MyISAM 10 Fixed 1 # # # 3072 # # # # # # #
ALTER TABLE t1 DISABLE KEYS;
SHOW TABLE STATUS LIKE 't1';
Name Engine Version Row_format Rows Avg_row_length Data_length Max_data_length Index_length Data_free Auto_increment Create_time Update_time Check_time Collation Checksum Create_options Comment
t1 MyISAM 10 Fixed 1 # # # 3072 # # # # # # #
ALTER TABLE t1 ENABLE KEYS;
SHOW TABLE STATUS LIKE 't1';
Name Engine Version Row_format Rows Avg_row_length Data_length Max_data_length Index_length Data_free Auto_increment Create_time Update_time Check_time Collation Checksum Create_options Comment
t1 MyISAM 10 Fixed 1 # # # 3072 # # # # # # #
ALTER TABLE t1 DISABLE KEYS;
SHOW TABLE STATUS LIKE 't1';
Name Engine Version Row_format Rows Avg_row_length Data_length Max_data_length Index_length Data_free Auto_increment Create_time Update_time Check_time Collation Checksum Create_options Comment
t1 MyISAM 10 Fixed 1 # # # 3072 # # # # # # #
ALTER TABLE t1 ENABLE KEYS;
SHOW TABLE STATUS LIKE 't1';
Name Engine Version Row_format Rows Avg_row_length Data_length Max_data_length Index_length Data_free Auto_increment Create_time Update_time Check_time Collation Checksum Create_options Comment
t1 MyISAM 10 Fixed 1 # # # 3072 # # # # # # #
DROP TABLE t1;
End of 5.0 tests End of 5.0 tests
...@@ -1161,4 +1161,30 @@ ALTER TABLE t1 ENABLE KEYS; ...@@ -1161,4 +1161,30 @@ ALTER TABLE t1 ENABLE KEYS;
SELECT a FROM t1 FORCE INDEX (inx) WHERE a=1; SELECT a FROM t1 FORCE INDEX (inx) WHERE a=1;
DROP TABLE t1; DROP TABLE t1;
#
# Bug#4692 - DISABLE/ENABLE KEYS waste a space
#
CREATE TABLE t1 (c1 INT, c2 INT, UNIQUE INDEX (c1), INDEX (c2)) ENGINE=MYISAM;
--replace_column 6 # 7 # 8 # 10 # 11 # 12 # 13 # 14 # 15 # 16 #
SHOW TABLE STATUS LIKE 't1';
INSERT INTO t1 VALUES (1,1);
--replace_column 6 # 7 # 8 # 10 # 11 # 12 # 13 # 14 # 15 # 16 #
SHOW TABLE STATUS LIKE 't1';
ALTER TABLE t1 DISABLE KEYS;
--replace_column 6 # 7 # 8 # 10 # 11 # 12 # 13 # 14 # 15 # 16 #
SHOW TABLE STATUS LIKE 't1';
ALTER TABLE t1 ENABLE KEYS;
--replace_column 6 # 7 # 8 # 10 # 11 # 12 # 13 # 14 # 15 # 16 #
SHOW TABLE STATUS LIKE 't1';
ALTER TABLE t1 DISABLE KEYS;
--replace_column 6 # 7 # 8 # 10 # 11 # 12 # 13 # 14 # 15 # 16 #
SHOW TABLE STATUS LIKE 't1';
ALTER TABLE t1 ENABLE KEYS;
--replace_column 6 # 7 # 8 # 10 # 11 # 12 # 13 # 14 # 15 # 16 #
SHOW TABLE STATUS LIKE 't1';
#--exec ls -log var/master-data/test/t1.MYI
#--exec myisamchk -dvv var/master-data/test/t1.MYI
#--exec myisamchk -iev var/master-data/test/t1.MYI
DROP TABLE t1;
--echo End of 5.0 tests --echo End of 5.0 tests
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