Test that all MERGE tables comes from the same database

@item

@code{LIMIT} on negative numbers are treated as big positive numbers.

@item

If you use @code{ALTER TABLE} to first add an @code{UNIQUE} index to a

table used in a @code{MERGE} table and then use @code{ALTER TABLE} to

add a normal index on the @code{MERGE} table, the key order will be

different for the tables if there was an old not-unique key in the

table. This is because @code{ALTER TABLE} puts @code{UNIQUE} keys before

normal keys to be able to detect duplicate keys as early as possible.

@end itemize

The following are known bugs in earlier versions of MySQL:

@example

CC="cc -pthread"

CFLAGS="-O4 -ansi_alias -ansi_args -fast -inline speed -speculate all -arch host"

CFLAGS="-O4 -ansi_alias -ansi_args -fast -inline speed all -arch host"

CXX="cxx -pthread"

CXXFLAGS="-O4 -ansi_alias -ansi_args -fast -inline speed -speculate all -arch host"

CXXFLAGS="-O4 -ansi_alias -ansi_args -fast -inline speed all -arch host"

export CC CFLAGS CXX CXXFLAGS

./configure \

--prefix=/usr/local/mysql \

(MySQL marks the first @code{UNIQUE} key as the @code{PRIMARY KEY}

if no @code{PRIMARY KEY} was specified explicitly.)

@findex UNIQUE

@findex PRIMARY KEY

If you add a @code{UNIQUE INDEX} or @code{PRIMARY KEY} to a table, this

is stored before any not @code[UNIQUE} index so that MySQL can detect

duplicate keys as early as possible.

@findex ORDER BY

@item

@code{ORDER BY} allows you to create the new table with the rows in a

With identical tables we mean that all tables are created with identical

column and key information.  You can't put a MERGE over tables where the

columns are packed differently or doesn't have exactly the same columns.

Some of the tables can however be compressed with @code{myisampack}.

@xref{myisampack}.

columns are packed differently, doesn't have exactly the same columns or

have the keys in different order.  Some of the tables can however be

compressed with @code{myisampack}.  @xref{myisampack}.

When you create a @code{MERGE} table, you will get a @code{.frm} table

definition file and a @code{.MRG} table list file.  The @code{.MRG} just

contains a list of the index files (@code{.MYI} files) that should

be used as one.

be used as one.  All used tables must be in the same database as the

@code{MERGE} table itself.

For the moment you need to have @code{SELECT}, @code{UPDATE}, and

@code{DELETE} privileges on the tables you map to a @code{MERGE} table.

read the new definition file.

@end itemize

@node ISAM, HEAP, MERGE, Table types

@section ISAM Tables

@appendixsubsec Changes in release 3.23.42

@itemize @bullet

@item

Enforce that all tables in a @code{MERGE} table comes from the same

database.

@item

Fixed bug with @code{LOAD DATA INFILE} and transactional tables.

@item

Fix bug when using @code{INSERT DELAYED} with wrong column definition.

@item

Fixed bug in @code{InnoDB} and @code{AUTO_INCREMENT} columns.

@item

Fixed critical bug in @code{InnoDB} and @code{BLOB}'s.  If one has used

@code{BLOB}'s larger than 8K in an @code{InnoDB} table one must dump

the table with @code{mysqldump}, drop it and restore it from the dump.

@item

Applied large patch for OS/2 from Yuri Dario.

@item

Fixed problem with InnoDB when one could get the error @code{Can't

execute the given command...} even when one didn't have an active

transaction.

@item

Applied some fixes for Gemini.

Applied some minor fixes that concerns Gemini.

@item

Use real arithmetic operations even in integer context if not

all arguments are integers. (Fixes uncommon bug in some integer

#define ER_CREATE_DB_WITH_READ_LOCK 1209

#define ER_WRONG_ARGUMENTS 1210

#define ER_NO_PERMISSON_TO_CREATE_USER 1211

#define ER_ERROR_MESSAGES 212

#define ER_UNION_TABLES_IN_DIFFERENT_DIR 1212

#define ER_ERROR_MESSAGES 213

# The following should give errors

create table t4 (a int not null, b char(10), key(a)) type=MERGE UNION=(t1,t2);

--error 1016

select * from t4;

--error 1212

create table t5 (a int not null, b char(10), key(a)) type=MERGE UNION=(test.t1,test_2.t2);

# Because of windows, it's important that we drop the merge tables first!

drop table if exists t4,t3,t1,t2;

drop table if exists t5,t4,t3,t1,t2;

create table t1 (c char(10)) type=myisam;

create table t2 (c char(10)) type=myisam;

  int error;

  MY_INIT(argv[0]);

  start_value=4597269L;  best_t1=6001982L;  best_t2=5063828L;  best_type=4; /* mode=4513  add=8  type: 0 */

  start_value=6130115L; best_t1=3632784L;  best_t2=86437L;  best_type=3; /* mode=4229  add=2  type: 0 */

  if (get_options(argc,(char **) argv))

    exit(1);

int ha_myisammrg::index_read(byte * buf, const byte * key,

			  uint key_len, enum ha_rkey_function find_flag)

{

//  return (my_errno=HA_ERR_WRONG_COMMAND);

  statistic_increment(ha_read_key_count,&LOCK_status);

  int error=myrg_rkey(file,buf,active_index, key, key_len, find_flag);

  table->status=error ? STATUS_NOT_FOUND: 0;

int ha_myisammrg::index_read_idx(byte * buf, uint index, const byte * key,

				 uint key_len, enum ha_rkey_function find_flag)

{

//  return (my_errno=HA_ERR_WRONG_COMMAND);

  statistic_increment(ha_read_key_count,&LOCK_status);

  int error=myrg_rkey(file,buf,index, key, key_len, find_flag);

  table->status=error ? STATUS_NOT_FOUND: 0;

int ha_myisammrg::index_next(byte * buf)

{

//  return (my_errno=HA_ERR_WRONG_COMMAND);

  statistic_increment(ha_read_next_count,&LOCK_status);

  int error=myrg_rnext(file,buf,active_index);

  table->status=error ? STATUS_NOT_FOUND: 0;

int ha_myisammrg::index_prev(byte * buf)

{

// return (my_errno=HA_ERR_WRONG_COMMAND);

  statistic_increment(ha_read_prev_count,&LOCK_status);

  int error=myrg_rprev(file,buf, active_index);

  table->status=error ? STATUS_NOT_FOUND: 0;

int ha_myisammrg::index_first(byte * buf)

{

//  return (my_errno=HA_ERR_WRONG_COMMAND);

  statistic_increment(ha_read_first_count,&LOCK_status);

  int error=myrg_rfirst(file, buf, active_index);

  table->status=error ? STATUS_NOT_FOUND: 0;

int ha_myisammrg::index_last(byte * buf)

{

//  return (my_errno=HA_ERR_WRONG_COMMAND);

  statistic_increment(ha_read_last_count,&LOCK_status);

  int error=myrg_rlast(file, buf, active_index);

  table->status=error ? STATUS_NOT_FOUND: 0;