AUTO_INCREMENT support for MERGE (e20d9e06) · Commits · Software / OSDI20 Artifacts / mariadb

Docs/manual.texi

+14 −8

Original line number	Diff line number	Diff line
		@@ -37793,8 +37793,8 @@ The disadvantages with @code{MERGE} tables are:
		@itemize @bullet
		@item
		You can only use identical @code{MyISAM} tables for a @code{MERGE} table.
		@item
		@code{AUTO_INCREMENT} columns are not automatically updated on @code{INSERT}.
		@c @item
		@c @code{AUTO_INCREMENT} columns are not automatically updated on @code{INSERT}.
		@item
		@code{REPLACE} doesn't work.
		@item
		@@ -37834,13 +37834,13 @@ CREATE TABLE t1 (a INT AUTO_INCREMENT PRIMARY KEY, message CHAR(20));
		CREATE TABLE t2 (a INT AUTO_INCREMENT PRIMARY KEY, message CHAR(20));
		INSERT INTO t1 (message) VALUES ("Testing"),("table"),("t1");
		INSERT INTO t2 (message) VALUES ("Testing"),("table"),("t2");
		CREATE TABLE total (a INT NOT NULL, message CHAR(20), KEY(a))
		CREATE TABLE total (a INT AUTO_INCREMENT PRIMARY KEY, message CHAR(20))
		TYPE=MERGE UNION=(t1,t2) INSERT_METHOD=LAST;
		@end example

		Note that we didn't create a @code{UNIQUE} or @code{PRIMARY KEY} in the
		@code{total} table as the key isn't going to be unique in the @code{total}
		table.
		@c Note that we didn't create a @code{UNIQUE} or @code{PRIMARY KEY} in the
		@c @code{total} table as the key isn't going to be unique in the @code{total}
		@c table.

		Note that you can also manipulate the @file{.MRG} file directly from
		the outside of the MySQL server:
		@@ -37867,6 +37867,10 @@ mysql> SELECT * FROM total;
		+---+---------+
		@end example

		Note that the @code{a} column, though declared as @code{PRIMARY KEY},
		is not really unique, as @code{MERGE} table cannot enforce uniqueness
		over a set of underlying @code{MyISAM} tables.

		To remap a @code{MERGE} table you can do one of the following:

		@itemize @bullet
		@@ -37894,8 +37898,8 @@ The following are the known problems with @code{MERGE} tables:
		A @code{MERGE} table cannot maintain @code{UNIQUE} constraints over the
		whole table. When you do @code{INSERT}, the data goes into the first or
		last table (according to @code{INSERT_METHOD=xxx}) and this @code{MyISAM}
		table ensures that the data are unique, but it knows nothing about the
		first @code{MyISAM} table.
		table ensures that the data are unique, but it knows nothing about
		others @code{MyISAM} tables.
		@item
		@code{DELETE FROM merge_table} used without a @code{WHERE}
		will only clear the mapping for the table, not delete everything in the
		@@ -49699,6 +49703,8 @@ Our TODO section contains what we plan to have in 4.0. @xref{TODO MySQL 4.0}.
		@itemize @bullet
		@item
		Fixed a bug that made the pager option in the mysql client non-functional.
		@item
		Added full @code{AUTO_INCREMENT} support to @code{MERGE} tables.
		@end itemize

mysql-test/r/merge.result

+77 −10

Original line number	Diff line number	Diff line
		@@ -275,12 +275,12 @@ a b
		1 2
		drop table t3,t1,t2;
		drop table if exists t6, t5, t4, t3, t2, t1;
		create table t1 (a int not null, b int not null, key(a,b));
		create table t2 (a int not null, b int not null, key(a,b));
		create table t1 (a int not null, b int not null auto_increment, primary key(a,b));
		create table t2 (a int not null, b int not null auto_increment, primary key(a,b));
		create table t3 (a int not null, b int not null, key(a,b)) UNION=(t1,t2) INSERT_METHOD=NO;
		create table t4 (a int not null, b int not null, key(a,b)) TYPE=MERGE UNION=(t1,t2) INSERT_METHOD=NO;
		create table t5 (a int not null, b int not null, key(a,b)) TYPE=MERGE UNION=(t1,t2) INSERT_METHOD=FIRST;
		create table t6 (a int not null, b int not null, key(a,b)) TYPE=MERGE UNION=(t1,t2) INSERT_METHOD=LAST;
		create table t5 (a int not null, b int not null auto_increment, primary key(a,b)) TYPE=MERGE UNION=(t1,t2) INSERT_METHOD=FIRST;
		create table t6 (a int not null, b int not null auto_increment, primary key(a,b)) TYPE=MERGE UNION=(t1,t2) INSERT_METHOD=LAST;
		show create table t3;
		Table Create Table
		t3 CREATE TABLE `t3` (
		@@ -299,18 +299,18 @@ show create table t5;
		Table Create Table
		t5 CREATE TABLE `t5` (
		`a` int(11) NOT NULL default '0',
		`b` int(11) NOT NULL default '0',
		KEY `a` (`a`,`b`)
		`b` int(11) NOT NULL auto_increment,
		PRIMARY KEY (`a`,`b`)
		) TYPE=MRG_MyISAM INSERT_METHOD=FIRST UNION=(t1,t2)
		show create table t6;
		Table Create Table
		t6 CREATE TABLE `t6` (
		`a` int(11) NOT NULL default '0',
		`b` int(11) NOT NULL default '0',
		KEY `a` (`a`,`b`)
		`b` int(11) NOT NULL auto_increment,
		PRIMARY KEY (`a`,`b`)
		) TYPE=MRG_MyISAM INSERT_METHOD=LAST UNION=(t1,t2)
		insert into t1 values (1,1),(1,2),(1,3),(1,4);
		insert into t2 values (2,1),(2,2),(2,3),(2,4);
		insert into t1 values (1,NULL),(1,NULL),(1,NULL),(1,NULL);
		insert into t2 values (2,NULL),(2,NULL),(2,NULL),(2,NULL);
		select * from t3 order by b,a limit 3;
		a b
		select * from t4 order by b,a limit 3;
		@@ -461,6 +461,73 @@ a b
		5 2
		6 1
		6 2
		select 1;
		1
		1
		insert into t5 values (1,NULL),(5,NULL);
		insert into t6 values (2,NULL),(6,NULL);
		select * from t1 order by a,b;
		a b
		1 1
		1 2
		1 3
		1 4
		1 5
		4 1
		4 2
		5 1
		5 2
		5 3
		select * from t2 order by a,b;
		a b
		2 1
		2 2
		2 3
		2 4
		2 5
		6 1
		6 2
		6 3
		select * from t5 order by a,b;
		a b
		1 1
		1 2
		1 3
		1 4
		1 5
		2 1
		2 2
		2 3
		2 4
		2 5
		4 1
		4 2
		5 1
		5 2
		5 3
		6 1
		6 2
		6 3
		select * from t6 order by a,b;
		a b
		1 1
		1 2
		1 3
		1 4
		1 5
		2 1
		2 2
		2 3
		2 4
		2 5
		4 1
		4 2
		5 1
		5 2
		5 3
		6 1
		6 2
		6 3
		drop table if exists t6, t5, t4, t3, t2, t1;
		CREATE TABLE t1 ( a int(11) NOT NULL default '0', b int(11) NOT NULL default '0', PRIMARY KEY (a,b)) TYPE=MyISAM;
		INSERT INTO t1 VALUES (1,1), (2,1);

sql/ha_myisammrg.cc

+1 −2

Original line number	Diff line number	Diff line
		@@ -75,8 +75,7 @@ int ha_myisammrg::write_row(byte * buf)
		if (table->time_stamp)
		update_timestamp(buf+table->time_stamp-1);
		if (table->next_number_field && buf == table->record[0])
		return (my_errno=HA_ERR_WRONG_COMMAND);
		// update_auto_increment(); - [phi] have to check this before allowing it
		update_auto_increment();
		return myrg_write(file,buf);
		}

sql/ha_myisammrg.h

+1 −1

Original line number	Diff line number	Diff line
		@@ -34,7 +34,7 @@ class ha_myisammrg: public handler
		const char **bas_ext() const;
		ulong table_flags() const
		{
		return (HA_REC_NOT_IN_SEQ \| HA_READ_RND_SAME \|
		return (HA_REC_NOT_IN_SEQ \| HA_READ_RND_SAME \| HA_AUTO_PART_KEY \|
		HA_KEYPOS_TO_RNDPOS \| HA_LASTKEY_ORDER \|
		HA_NULL_KEY \| HA_BLOB_KEY);
		}

sql/handler.cc

+15 −2

Original line number	Diff line number	Diff line
		@@ -628,16 +628,29 @@ longlong handler::get_auto_increment()
		{
		longlong nr;
		int error;

		(void) extra(HA_EXTRA_KEYREAD);
		index_init(table->next_number_index);
		if (!table->next_number_key_offset)
		{ // Autoincrement at key-start
		error=index_last(table->record[1]);
		}
		else
		{
		byte key[MAX_KEY_LENGTH];
		key_copy(key,table,table->next_number_index,
		table->next_number_key_offset);
		error=index_read(table->record[1], key, table->next_number_key_offset,
		HA_READ_PREFIX_LAST);
		}

		if (error)
		nr=1;
		else
		nr=(longlong) table->next_number_field->
		val_int_offset(table->rec_buff_length)+1;
		(void) extra(HA_EXTRA_NO_KEYREAD);
		index_end();
		(void) extra(HA_EXTRA_NO_KEYREAD);
		return nr;
		}