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Merge work.mysql.com:/home/bk/mysql-4.0 into black.box:/u/home/tim/my/4

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Docs/manual.texi
View file @ 2050505f
......@@ -4265,9 +4265,9 @@ will only clear the mapping for the table, not delete everything in the
mapped tables.
@item
You cannot build in another directory when using
You cannot build the server in another directory when using
MIT-pthreads. Because this requires changes to MIT-pthreads, we are not
likely to fix this.
likely to fix this. @xref{MIT-pthreads}.
@item
@code{BLOB} values can't ``reliably'' be used in @code{GROUP BY} or
......@@ -4496,6 +4496,7 @@ should be read with that in mind. There are no factual errors contained
in this section that we know of. If you find something which you believe
to be an error, please contact us about it at @email{docs@@mysql.com}.
@c FIX this is bad lingo: "supported limits", etc.
For a list of all supported limits, functions, and types, see the
@code{crash-me} Web page at
@uref{http://www.mysql.com/information/crash-me.php}.
......@@ -4705,7 +4706,7 @@ differences in spelling between @code{mSQL} and MySQL for the
most-used C API functions.
For example, it changes instances of @code{msqlConnect()} to
@code{mysql_connect()}. Converting a client program from @code{mSQL} to
MySQL usually takes a couple of minutes.
MySQL usually requires only minor effort.
@end table
@menu
......@@ -4722,7 +4723,7 @@ MySQL usually takes a couple of minutes.
@cindex converting, tools
@cindex tools, converting
According to our experience, it would just take a few hours to convert tools
According to our experience, it doesn't take long to convert tools
such as @code{msql-tcl} and @code{msqljava} that use the
@code{mSQL} C API so that they work with the MySQL C API.
......@@ -4824,8 +4825,10 @@ Has the following additional types (among others;
@pxref{CREATE TABLE, , @code{CREATE TABLE}}):
@itemize @bullet
@item
@c FIX bad lingo, needs rephrasing
@code{ENUM} type for one of a set of strings.
@item
@c FIX bad lingo, needs rephrasing
@code{SET} type for many of a set of strings.
@item
@code{BIGINT} type for 64-bit integers.
......@@ -5381,11 +5384,11 @@ benchmark page.
Before going to the other benchmarks we know of, we would like to give
some background on benchmarks:
It's very easy to write a test that shows ANY database to be best
It's very easy to write a test that shows ANY database to be the best
database in the world, by just restricting the test to something the
database is very good at and not test anything that the database is not
good at. If one after this publishes the result with a single figure,
things are even easier.
database is very good at and not testing anything that the database is
not good at. If one, after doing this, summarises the result with as
a single figure, things are even easier.
This would be like us measuring the speed of MySQL compared to PostgreSQL
by looking at the summary time of the MySQL benchmarks on our web page.
......@@ -5692,9 +5695,9 @@ derived tables for the duration of the query.
@item
Add @code{PREPARE} of statements and sending of parameters to @code{mysqld}.
@item
Extend the server/client protocol to support warnings.
Extend the client/server protocol to support warnings.
@item
Add options to the server/protocol protocol to get progress notes
Add options to the client/server protocol to get progress notes
for long running commands.
@item
Add database and real table name (in case of alias) to the MYSQL_FIELD
......@@ -14899,10 +14902,14 @@ select * from shop where price=@@min_price or price=@@max_price;
@cindex foreign keys
@cindex keys, foreign
You don't need foreign keys to join 2 tables.
In MySQL 3.23.44 and up, @code{InnoDB} tables supports checking of
foreign key constraints. @xref{InnoDB}.
See also @ref{example-Foreign keys}.
The only thing MySQL doesn't do is @code{CHECK} to make sure that
the keys you use really exist in the table(s) you're referencing and it
You don't actually need foreign keys to join 2 tables.
The only thing MySQL currently doesn't do (in type types other than
@code{InnoDB}), is @code{CHECK} to make sure that the keys you use
really exist in the table(s) you're referencing and it
doesn't automatically delete rows from a table with a foreign key
definition. If you use your keys like normal, it'll work just fine:
......@@ -37448,37 +37455,85 @@ SUM_OVER_ALL_KEYS(max_length_of_key + sizeof(char*) * 2)
@section InnoDB Tables
@menu
* InnoDB overview:: InnoDB tables overview
* InnoDB start:: InnoDB startup options
* InnoDB init:: Creating InnoDB table space.
* Using InnoDB tables:: Creating InnoDB tables
* Adding and removing:: Adding and removing InnoDB data and log files
* Backing up:: Backing up and recovering an InnoDB database
* Moving:: Moving an InnoDB database to another machine
* InnoDB transaction model:: InnoDB transaction model.
* Implementation:: Implementation of multiversioning
* Table and index:: Table and index structures
* File space management:: File space management and disk i/o
* Error handling:: Error handling
* InnoDB restrictions:: Restrictions on InnoDB tables
* InnoDB contact information:: InnoDB contact information.
* InnoDB overview:: InnoDB Tables Overview
* InnoDB start:: InnoDB Startup Options
* InnoDB init:: Creating InnoDB Tablespace
* Using InnoDB tables:: Creating InnoDB Tables
* Adding and removing:: Adding and Removing InnoDB Data and Log Files
* Backing up:: Backing up and Recovering an InnoDB Database
* Moving:: Moving an InnoDB Database to Another Machine
* InnoDB transaction model:: InnoDB Transaction Model.
* Implementation:: Implementation of Multiversioning
* Table and index:: Table and Index Structures
* File space management:: File Space Management and Disk i/o
* Error handling:: Error Handling
* InnoDB restrictions:: Restrictions on InnoDB Tables
* InnoDB contact information:: InnoDB Contact Information.
@end menu
@node InnoDB overview, InnoDB start, InnoDB, InnoDB
@subsection InnoDB tables overview
@subsection InnoDB Tables Overview
InnoDB provides MySQL with a transaction-safe table handler with
commit, rollback, and crash recovery capabilities. InnoDB does
locking on row level and also provides an Oracle-style
consistent
non-locking read in @code{SELECT}s. These features increase
multiuser concurrency and performance. There is no need for
lock escalation in InnoDB,
because row level locks in InnoDB fit in very small space.
InnoDB tables support @code{FOREIGN KEY} constraints
as the first table type in MySQL.
InnoDB has been designed for maximum performance
when processing
large data volumes. Its CPU efficiency is probably not
matched by any other disk-based relational database engine.
Technically, InnoDB is a complete database backend placed under MySQL.
InnoDB has its own buffer pool for caching data and indexes in main
memory. InnoDB stores its tables and indexes in a tablespace, which
may consist of several files. This is different from, for example,
MyISAM tables where each table is stored as a separate file.
InnoDB tables can be of any size also on those operating
systems where file size is limited to 2 GB.
You can find the latest information about InnoDB at
@uref{http://www.innodb.com}. The most up-to-date version of the
InnoDB manual is always placed there, and you can also order
commercial licenses and support for InnoDB.
InnoDB is currently (October 2001) used in production at
several large database sites requiring high performance.
The famous Internet news site Slashdot.org runs on
InnoDB. Mytrix, Inc. stores over 1 TB of data in
InnoDB, and another site handles an average
load of 800 inserts/updates per second in InnoDB.
InnoDB tables are included in the MySQL source distribution
starting from 3.23.34a and are activated in the @strong{MySQL -max}
binary.
starting from 3.23.34a and are activated in the MySQL -Max
binary. For Windows the -Max binaries are contained in the
standard distribution.
If you have downloaded a binary version of MySQL that includes
support for InnoDB (mysqld-max), simply follow the instructions for
installing a binary version of MySQL. @xref{Installing binary}.
support for InnoDB, simply follow the instructions of the
MySQL manual
for installing a binary version of MySQL. If you already have
MySQL-3.23 installed, then the simplest way to install
MySQL -Max is to replace the server executable @file{mysqld}
with the corresponding executable in the -Max distribution.
MySQL and MySQL -Max differ only in the server executable.
@xref{Installing binary}.
@xref{mysqld-max, , @code{mysqld-max}}.
To compile MySQL with InnoDB support, download MySQL-3.23.37 or newer
and configure MySQL with the @code{--with-innodb} option.
To compile MySQL with InnoDB support,
download MySQL-3.23.34a or newer version from
@uref{http://www.mysql.com}
and configure MySQL with the
@code{--with-innodb} option. See the
MySQL manual
about installing a MySQL source distribution.
@xref{Installing source}.
@example
......@@ -37486,47 +37541,23 @@ cd /path/to/source/of/mysql-3.23.37
./configure --with-innodb
@end example
To get InnoDB to work you have to specify where the data for InnoDB
tables should be stored by specifying the @code{innodb_data_file_path}
option on the command line or in an MySQL option file. @xref{InnoDB
start}. If you have configured MySQL for InnoDB but you have not
specified the above option, @code{mysqld} will print at start:
To use InnoDB you have to specify InnoDB startup options in
your @file{my.cnf} or @file{my.ini} file. The minimal way
to modify it is to add to the @code{[mysqld]} section the line
@example
Can't initialize InnoDB as 'innodb_data_file_path' is not set
innodb_data_file_path=ibdata:30M
@end example
InnoDB provides MySQL with a transaction-safe table handler with
commit, rollback, and crash recovery capabilities. InnoDB does
locking on row level, and also provides an Oracle-style consistent
non-locking read in @code{SELECT}s, which increases transaction
concurrency. There is not need for lock escalation in InnoDB,
because row level locks in InnoDB fit in very small space.
InnoDB has been designed for maximum performance when processing
large data volumes. Its CPU efficiency is probably not
matched by any other disk-based relational database engine.
You can find the latest information about InnoDB at
@uref{http://www.innodb.com}. The most up-to-date version of the
InnoDB manual is always placed there, and you can also order commercial
support for InnoDB.
Technically, InnoDB is a database backend placed under MySQL. InnoDB
has its own buffer pool for caching data and indexes in main
memory. InnoDB stores its tables and indexes in a tablespace, which
may consist of several files. This is different from, for example,
@code{MyISAM} tables where each table is stored as a separate file.
but to get good performance it is best that you specify options
like recommended below in the section 'InnoDB startup options'.
InnoDB is distributed under the GNU GPL License Version 2 (of June 1991).
In the source distribution of MySQL, InnoDB appears as a subdirectory.
@node InnoDB start, InnoDB init, InnoDB overview, InnoDB
@subsection InnoDB startup options
Beginning from MySQL-3.23.37 the prefix of the options is changed
from @code{innobase_...} to @code{innodb_...}.
@subsection InnoDB Startup Options
To use InnoDB tables you @strong{MUST} specify configuration parameters
in the MySQL configuration file in the @code{[mysqld]} section of
......@@ -37540,6 +37571,10 @@ hard disk. Below is an example of possible configuration parameters in
@file{my.cnf} for InnoDB:
@example
[mysqld]
# You can write your other MySQL server options here
# ...
#
innodb_data_file_path = ibdata1:2000M;ibdata2:2000M
innodb_data_home_dir = c:\ibdata
set-variable = innodb_mirrored_log_groups=1
......@@ -37548,19 +37583,34 @@ set-variable = innodb_log_files_in_group=3
set-variable = innodb_log_file_size=30M
set-variable = innodb_log_buffer_size=8M
innodb_flush_log_at_trx_commit=1
#.._arch_dir must be the same as .._log_group_home_dir
innodb_log_arch_dir = c:\iblogs
innodb_log_archive=0
set-variable = innodb_buffer_pool_size=80M
set-variable = innodb_buffer_pool_size=70M
set-variable = innodb_additional_mem_pool_size=10M
set-variable = innodb_file_io_threads=4
set-variable = innodb_lock_wait_timeout=50
@end example
Note that data files must be < 4G, and < 2G on
some file systems! The total size of data files has
Note that some operating systems
restrict file size to < 2G.
The total size of data files has
to be >= 10 MB.
InnoDB does not create directories:
you have to create them yourself.
Check that the MySQL server
has the rights to create files in the directories you specify.
When you the first time create an InnoDB database, it
is best that you start the MySQL server from the command
prompt. Then InnoDB will print the information about the
database creation to the screen, and you see what is
happening. See below in section 3 what the printout
should look like.
For example, in Windows you can start @file{mysqld-max.exe} with:
@example
your-path-to-mysqld>mysqld-max --standalone --console
@end example
Suppose you have a Linux machine with 512 MB RAM and
three 20 GB hard disks (at directory paths @file{/},
......@@ -37569,6 +37619,10 @@ Below is an example of possible configuration parameters in @file{my.cnf} for
InnoDB:
@example
[mysqld]
# You can write your other MySQL server options here
# ...
#
innodb_data_file_path = ibdata/ibdata1:2000M;dr2/ibdata/ibdata2:2000M
innodb_data_home_dir = /
set-variable = innodb_mirrored_log_groups=1
......@@ -37577,9 +37631,10 @@ set-variable = innodb_log_files_in_group=3
set-variable = innodb_log_file_size=50M
set-variable = innodb_log_buffer_size=8M
innodb_flush_log_at_trx_commit=1
#.._arch_dir must be the same as .._log_group_home_dir
innodb_log_arch_dir = /dr3/iblogs
innodb_log_archive=0
set-variable = innodb_buffer_pool_size=400M
set-variable = innodb_buffer_pool_size=350M
set-variable = innodb_additional_mem_pool_size=20M
set-variable = innodb_file_io_threads=4
set-variable = innodb_lock_wait_timeout=50
......@@ -37605,9 +37660,12 @@ The common part of the directory path for all InnoDB data files.
Paths to individual data files and their sizes. The full directory path
to each data file is acquired by concatenating innodb_data_home_dir to
the paths specified here. The file sizes are specified in megabytes,
hence the 'M' after the size specification above. Do not set a file size
bigger than 4000M, and on most operating systems not bigger than 2000M.
hence the 'M' after the size specification above.
InnoDB also understands the abbreviation 'G', 1G meaning 1024M.
Starting from
3.23.44 you can set the file size bigger than 4 GB on those
operating systems which support big files.
On some operating systems files must be < 2 GB.
The sum of the sizes of the files must be at least 10 MB.
@item @code{innodb_mirrored_log_groups} @tab
Number of identical copies of log groups we
......@@ -37622,7 +37680,8 @@ Size of each log file in a log group in megabytes. Sensible values range
from 1M to the size of the buffer pool specified below. The bigger the
value, the less checkpoint flush activity is needed in the buffer pool,
saving disk i/o. But bigger log files also mean that recovery will be
slower in case of a crash. File size restriction as for a data file.
slower in case of a crash. The combined size of log files must
be < 4 GB on 32-bit computers.
@item @code{innodb_log_buffer_size} @tab
The size of the buffer which InnoDB uses to write log to the log files
on disk. Sensible values range from 1M to half the combined size of log
......@@ -37647,7 +37706,7 @@ archive InnoDB log files.
The size of the memory buffer InnoDB uses to cache data and indexes of
its tables. The bigger you set this the less disk i/o is needed to
access data in tables. On a dedicated database server you may set this
parameter up to 90 % of the machine physical memory size. Do not set it
parameter up to 80 % of the machine physical memory size. Do not set it
too large, though, because competition of the physical memory may cause
paging in the operating system.
@item @code{innodb_additional_mem_pool_size} @tab
......@@ -37659,7 +37718,7 @@ will start to allocate memory from the operating system, and write
warning messages to the MySQL error log.
@item @code{innodb_file_io_threads} @tab
Number of file i/o threads in InnoDB. Normally, this should be 4, but
on Windows NT disk i/o may benefit from a larger number.
on Windows disk i/o may benefit from a larger number.
@item @code{innodb_lock_wait_timeout} @tab
Timeout in seconds an InnoDB transaction may wait for a lock before
being rolled back. InnoDB automatically detects transaction deadlocks
......@@ -37676,7 +37735,7 @@ Another option is @code{O_DSYNC}.
@node InnoDB init, Using InnoDB tables, InnoDB start, InnoDB
@subsection Creating InnoDB table space
@subsection Creating InnoDB Tablespace
Suppose you have installed MySQL and have edited @file{my.cnf} so that
it contains the necessary InnoDB configuration parameters.
......@@ -37742,7 +37801,7 @@ mysqld: ready for connections
@node Error creating InnoDB, , InnoDB init, InnoDB init
@subsubsection If something goes wrong in database creation
@subsubsection If Something Goes Wrong in Database Creation
If something goes wrong in an InnoDB database creation, you should
delete all files created by InnoDB. This means all data files, all log
......@@ -37753,7 +37812,7 @@ directories. Then you can try the InnoDB database creation again.
@node Using InnoDB tables, Adding and removing, InnoDB init, InnoDB
@subsection Creating InnoDB tables
@subsection Creating InnoDB Tables
Suppose you have started the MySQL client with the command
@code{mysql test}.
......@@ -37787,15 +37846,7 @@ Note that the statistics @code{SHOW} gives about InnoDB tables
are only approximate: they are used in SQL optimisation. Table and
index reserved sizes in bytes are accurate, though.
NOTE: @code{DROP DATABASE} does not currently work for InnoDB tables!
You must drop the tables individually. Also take care not to delete or
add @file{.frm} files to your InnoDB database manually: use
@code{CREATE TABLE} and @code{DROP TABLE} commands.
InnoDB has its own internal data dictionary, and you will get problems
if the MySQL @file{.frm} files are out of 'sync' with the InnoDB
internal data dictionary.
@subsubsection Converting MyISAM tables to InnoDB
@subsubsection Converting MyISAM Tables to InnoDB
InnoDB does not have a special optimisation for separate index creation.
Therefore it does not pay to export and import the table and create indexes
......@@ -37835,9 +37886,55 @@ it is better that you kill the database process and delete all InnoDB data
and log files and all InnoDB table @file{.frm} files, and start
your job again, rather than wait for millions of disk i/os to complete.
@subsubsection Foreign Key Constraints
InnoDB version 3.23.44 features foreign key constraints. InnoDB is the
first MySQL table type which allows you to define foreign key
constraints to guard the integrity of your data.
An example:
@example
CREATE TABLE parent(id INT NOT NULL, PRIMARY KEY (id)) TYPE=INNODB;
CREATE TABLE child(id INT, parent_id INT, INDEX par_ind (parent_id),
FOREIGN KEY (parent_id) REFERENCES parent(id)) TYPE=INNODB;
@end example
Both tables have to be InnoDB type and there must be an index
where the foreign key and the referenced key are listed as the first
columns. Any @code{ALTER TABLE} currently removes all foreign key
constrainst defined for the table, but not the constraints
that reference the table. Corresponding columns in the foreign key
and the referenced key have to have similar internal data types
inside InnoDB so that they can be compared without a type
conversion. The length of string types need not be the same.
The size and the signedness of integer types has to be same.
When doing foreign key checks InnoDB sets shared row
level locks on child or parent records it has to look at.
InnoDB allows you to drop any table even though that
would break the foreign key constraints which reference
the table. When you drop a table the constraints which
were defined in its create statement are also dropped.
If you recreate a table which was dropped, it has to have
a definition which conforms to the foreign key constraints
referencing it. It must have the right column names and types,
and it must have indexes on the referenced keys, as stated above.
You can list the foreign key constraints for a table
@code{T} with
@example
SHOW TABLE STATUS FROM yourdatabasename LIKE 'T';
@end example
The foreign key constraints are listed in the table comment of
the output.
InnoDB does not yet support @code{CASCADE ON DELETE}
or other special options on the constraints.
@node Adding and removing, Backing up, Using InnoDB tables, InnoDB
@subsection Adding and removing InnoDB data and log files
@subsection Adding and Removing InnoDB Data and Log Files
You cannot increase the size of an InnoDB data file. To add more into
your tablespace you have to add a new data file. To do this you have to
......@@ -37846,7 +37943,7 @@ new file to @code{innodb_data_file_path}, and then start MySQL
again.
Currently you cannot remove a data file from InnoDB. To decrease the
size of your database you have to use @code{mysqldump} to dump
size of your database you have to use @file{mysqldump} to dump
all your tables, create a new database, and import your tables to the
new database.
......@@ -37860,7 +37957,7 @@ you at the startup that it is creating new log files.
@node Backing up, Moving, Adding and removing, InnoDB
@subsection Backing up and recovering an InnoDB database
@subsection Backing up and Recovering an InnoDB Database
The key to safe database management is taking regular backups.
To take a 'binary' backup of your database you have to do the following:
......@@ -37979,7 +38076,7 @@ because there will be more log to apply to the database.
@node Moving, InnoDB transaction model, Backing up, InnoDB
@subsection Moving an InnoDB database to another machine
@subsection Moving an InnoDB Database to Another Machine
InnoDB data and log files are binary-compatible on all platforms
if the floating point number format on the machines is the same.
......@@ -38000,10 +38097,10 @@ a table.
@node InnoDB transaction model, Implementation, Moving, InnoDB
@subsection InnoDB transaction model
@subsection InnoDB Transaction Model
In the InnoDB transaction model the goal has been to combine the best
sides of a multiversioning database to traditional two-phase locking.
properties of a multiversioning database to traditional two-phase locking.
InnoDB does locking on row level and runs queries by default
as non-locking consistent reads, in the style of Oracle.
The lock table in InnoDB is stored so space-efficiently that lock
......@@ -38012,7 +38109,7 @@ to lock every row in the database, or any random subset of the rows,
without InnoDB running out of memory.
In InnoDB all user activity happens inside transactions. If the
auto commit mode is used in MySQL, then each SQL statement
auto-commit mode is used in MySQL, then each SQL statement
will form a single transaction. If the auto commit mode is
switched off, then we can think that a user always has a transaction
open. If he issues
......@@ -38026,17 +38123,17 @@ on the other hand cancels all modifications made by the current
transaction.
@menu
* InnoDB consistent read:: Consistent read
* InnoDB locking reads:: Locking reads
* InnoDB Next-key locking:: Next-key locking: avoiding the phantom problem
* InnoDB Locks set:: Locks set by different SQL statements in InnoDB
* InnoDB Deadlock detection:: Deadlock detection and rollback
* InnoDB Consistent read example:: An example of how the consistent read works in InnoDB
* InnoDB consistent read:: Consistent Read
* InnoDB locking reads:: Locking Reads
* InnoDB Next-key locking:: Next-key Locking: Avoiding the Phantom Problem
* InnoDB Locks set:: Locks Set by Different SQL Statements in InnoDB
* InnoDB Deadlock detection:: Deadlock Detection and Rollback
* InnoDB Consistent read example:: An Example of How the Consistent Read Works in InnoDB
@end menu
@node InnoDB consistent read, InnoDB locking reads, InnoDB transaction model, InnoDB transaction model
@subsubsection Consistent read
@subsubsection Consistent Read
A consistent read means that InnoDB uses its multiversioning to
present to a query a snapshot of the database at a point in time.
......@@ -38062,7 +38159,7 @@ on the table.
@node InnoDB locking reads, InnoDB Next-key locking, InnoDB consistent read, InnoDB transaction model
@subsubsection Locking reads
@subsubsection Locking Reads
A consistent read is not convenient in some circumstances.
Suppose you want to add a new row into your table @code{CHILD},
......@@ -38120,7 +38217,7 @@ on the rows.
@node InnoDB Next-key locking, InnoDB Locks set, InnoDB locking reads, InnoDB transaction model
@subsubsection Next-key locking: avoiding the phantom problem
@subsubsection Next-key Locking: Avoiding the Phantom Problem
In row level locking InnoDB uses an algorithm called next-key locking.
InnoDB does the row level locking so that when it searches or
......@@ -38164,7 +38261,7 @@ after the last record in the index. Just that happens in the previous
example: the locks set by InnoDB will prevent any insert to
the table where @code{ID} would be bigger than 100.
You can use the next-key locking to implement a uniqueness
You can use next-key locking to implement a uniqueness
check in your application: if you read your data in share mode
and do not see a duplicate for a row you are going to insert,
then you can safely insert your row and know that the next-key
......@@ -38173,9 +38270,8 @@ anyone meanwhile inserting a duplicate for your row. Thus the next-key
locking allows you to 'lock' the non-existence of something in your
table.
@node InnoDB Locks set, InnoDB Deadlock detection, InnoDB Next-key locking, InnoDB transaction model
@subsubsection Locks set by different SQL statements in InnoDB
@subsubsection Locks Set by Different SQL Statements in InnoDB
@itemize @bullet
@item
......@@ -38216,6 +38312,12 @@ lock on every record the search encounters.
@code{DELETE FROM ... WHERE ...} : sets an exclusive next-key
lock on every record the search encounters.
@item
If a @code{FOREIGN KEY} constraint is defined on a table,
any insert, update, or delete which requires checking of the constraint
condition sets shared record level locks on the records it
looks at to check the constraint. Also in the case where the
constraint fails, InnoDB sets these locks.
@item
@code{LOCK TABLES ... } : sets table locks. In the implementation
the MySQL layer of code sets these locks. The automatic deadlock detection
of InnoDB cannot detect deadlocks where such table locks are involved:
......@@ -38228,7 +38330,7 @@ locks. But that does not put transaction integerity into danger.
@node InnoDB Deadlock detection, InnoDB Consistent read example, InnoDB Locks set, InnoDB transaction model
@subsubsection Deadlock detection and rollback
@subsubsection Deadlock Detection and Rollback
InnoDB automatically detects a deadlock of transactions and rolls
back the transaction whose lock request was the last one to build
......@@ -38247,7 +38349,7 @@ stores row locks in a format where it cannot afterwards know which was
set by which SQL statement.
@node InnoDB Consistent read example, , InnoDB Deadlock detection, InnoDB transaction model
@subsubsection An example of how the consistent read works in InnoDB
@subsubsection An Example of How the Consistent Read Works in InnoDB
When you issue a consistent read, that is, an ordinary @code{SELECT}
statement, InnoDB will give your transaction a timepoint according
......@@ -38279,9 +38381,9 @@ v SELECT * FROM t;
COMMIT;
SELECT * FROM t;
----------------------
---------------------
| 1 | 2 |
----------------------
---------------------
@end example
Thus user A sees the row inserted by B only when B has committed the
......@@ -38296,7 +38398,7 @@ SELECT * FROM t LOCK IN SHARE MODE;
@end example
@subsection Performance tuning tips
@subsection Performance Tuning Tips
@strong{1.}
If the Unix @file{top} or the Windows @file{Task Manager} shows that
......@@ -38388,15 +38490,24 @@ This tip is of course valid for inserts into any table type, not just InnoDB.
Starting from version 3.23.41 InnoDB includes the InnoDB
Monitor which prints information on the InnoDB internal state.
When swithed on, InnoDB Monitor
will make the MySQL server to print data to the standard
output about once every 10 seconds. This data is useful in
will make the MySQL server @file{mysqld} to print data
(note: the MySQL client will not print anything)
to the standard
output about once every 15 seconds. This data is useful in
performance tuning.
On Windows you must start @code{mysqld-max}
from a MS-DOS prompt
with the @code{--standalone --console}
options to direct the output to the MS-DOS prompt
window.
There is a separate @code{innodb_lock_monitor} which
prints the same information as @code{innodb_monitor}
plus information on locks set by each transaction.
The printed information includes data on:
@itemize @bullet
@item
table and record locks held by each active transaction,
@item
lock waits of a transactions,
@item
semaphore waits of threads,
......@@ -38509,8 +38620,8 @@ may have lock contention. The output can also help to
trace reasons for transaction deadlocks.
@item
Section SYNC INFO will report reserved semaphores
if you compile InnoDB with <code>UNIV_SYNC_DEBUG</code>
defined in <tt>univ.i</tt>.
if you compile InnoDB with @code{UNIV_SYNC_DEBUG}
defined in @file{univ.i}.
@item
Section SYNC ARRAY INFO reports threads waiting
for a semaphore and statistics on how many times
......@@ -38532,7 +38643,7 @@ currently doing.
@end itemize
@node Implementation, Table and index, InnoDB transaction model, InnoDB
@subsection Implementation of multiversioning
@subsection Implementation of Multiversioning
Since InnoDB is a multiversioned database, it must keep information
of old versions of rows in the tablespace. This information is stored
......@@ -38563,7 +38674,9 @@ a snapshot that in a consistent read could need the information
in the update undo log to build an earlier version of a database
row.
You must remember to commit your transactions regularly. Otherwise
You must remember to commit your transactions regularly,
also those transactions which only issue consistent reads.
Otherwise
InnoDB cannot discard data from the update undo logs, and the
rollback segment may grow too big, filling up your tablespace.
......@@ -38582,7 +38695,19 @@ time as the SQL statement which did the deletion.
@node Table and index, File space management, Implementation, InnoDB
@subsection Table and index structures
@subsection Table and Index Structures
MySQL stores its data dictionary information of tables
in @file{.frm}
files in database directories. But every InnoDB type table
also has its own entry in InnoDB internal data dictionaries
inside the tablespace. When MySQL drops a table or a database,
it has to delete both a @file{.frm} file or files, and
the corresponding entries inside the InnoDB data dictionary.
This is the reason why you cannot move InnoDB tables between
databases simply by moving the @file{.frm} files, and why
@code{DROP DATABASE} did not work for InnoDB type tables
in MySQL versions <= 3.23.43.
Every InnoDB table has a special index called the clustered index
where the data of the rows is stored. If you define a
......@@ -38610,15 +38735,15 @@ index. Note that if the primary key is long, the secondary indexes
will use more space.
@menu
* InnoDB physical structure:: Physical structure of an index
* InnoDB Insert buffering:: Insert buffering
* InnoDB Adaptive hash:: Adaptive hash indexes
* InnoDB Physical record:: Physical record structure
* InnoDB physical structure:: Physical Structure of an Index
* InnoDB Insert buffering:: Insert Buffering
* InnoDB Adaptive hash:: Adaptive Hash Indexes
* InnoDB Physical record:: Physical Record Structure
@end menu
@node InnoDB physical structure, InnoDB Insert buffering, Table and index, Table and index
@subsubsection Physical structure of an index
@subsubsection Physical Structure of an Index
All indexes in InnoDB are B-trees where the index records are
stored in the leaf pages of the tree. The default size of an index
......@@ -38634,7 +38759,7 @@ InnoDB will try to contract the index tree to free the page.
@node InnoDB Insert buffering, InnoDB Adaptive hash, InnoDB physical structure, Table and index
@subsubsection Insert buffering
@subsubsection Insert Buffering
It is a common situation in a database application that the
primary key is a unique identifier and new rows are inserted in the
......@@ -38662,7 +38787,7 @@ to a table up to 15 times.
@node InnoDB Adaptive hash, InnoDB Physical record, InnoDB Insert buffering, Table and index
@subsubsection Adaptive hash indexes
@subsubsection Adaptive Hash Indexes
If a database fits almost entirely in main memory, then the fastest way
to perform queries on it is to use hash indexes. InnoDB has an
......@@ -38686,7 +38811,7 @@ databases.
@node InnoDB Physical record, , InnoDB Adaptive hash, Table and index
@subsubsection Physical record structure
@subsubsection Physical Record Structure
@itemize @bullet
@item
......@@ -38709,7 +38834,7 @@ If the total length of the fields in a record is < 128 bytes, then
the pointer is 1 byte, else 2 bytes.
@end itemize
@subsubsection How an auto-increment column works in InnoDB
@subsubsection How an Auto-increment Column Works in InnoDB
After a database startup, when a user first does an insert to a
table @code{T}
......@@ -38718,16 +38843,16 @@ an explicit value for the column, then InnoDB executes @code{SELECT
MAX(auto-inc-column) FROM T}, and assigns that value incremented
by one to the the column and the auto-increment counter of the table.
We say that
the auto-increment counter for table @code{T} has been initialised.
the auto-increment counter for table @code{T} has been initialized.
InnoDB follows the same procedure in initialising the auto-increment counter
InnoDB follows the same procedure in initializing the auto-increment counter
for a freshly created table.
Note that if the user specifies in an insert the value 0 to the auto-increment
column, then InnoDB treats the row like the value would not have been
specified.
After the auto-increment counter has been initialised, if a user inserts
After the auto-increment counter has been initialized, if a user inserts
a row where he explicitly specifies the column value, and the value is bigger
than the current counter value, then the counter is set to the specified
column value. If the user does not explicitly specify a value, then InnoDB
......@@ -38744,12 +38869,12 @@ integer that can be stored in the specified integer type.
@node File space management, Error handling, Table and index, InnoDB
@subsection File space management and disk i/o
@subsection File Space Management and Disk i/o
@menu
* InnoDB Disk i/o:: Disk i/o
* InnoDB File space:: File space management
* InnoDB File Defragmenting:: Defragmenting a table
* InnoDB File space:: File Space Management
* InnoDB File Defragmenting:: Defragmenting a Table
@end menu
......@@ -38792,7 +38917,7 @@ file size in @code{innodb_data_file_path}. The partition must be
1000 000 bytes.
@example
innodb_data_file_path=hdd1:3Gnewraw;hdd2:2Gnewraw
innodb_data_file_path=hdd1:5Gnewraw;hdd2:2Gnewraw
@end example
When you start the database again you MUST change the keyword
......@@ -38800,10 +38925,10 @@ to @code{raw}. Otherwise InnoDB will write over your
partition!
@example
innodb_data_file_path=hdd1:3Graw;hdd2:2Graw
innodb_data_file_path=hdd1:5Graw;hdd2:2Graw
@end example
Using a raw disk you can on some Unixes perform non-buffered i/o.
By using a raw disk you can on some Unixes perform unbuffered i/o.
There are two read-ahead heuristics in InnoDB: sequential read-ahead
and random read-ahead. In sequential read-ahead InnoDB notices that
......@@ -38816,7 +38941,7 @@ reads to the i/o system.
@node InnoDB File space, InnoDB File Defragmenting, InnoDB Disk i/o, File space management
@subsubsection File space management
@subsubsection File Space Management
The data files you define in the configuration file form the tablespace
of InnoDB. The files are simply catenated to form the tablespace,
......@@ -38864,7 +38989,7 @@ consistent read.
@node InnoDB File Defragmenting, , InnoDB File space, File space management
@subsubsection Defragmenting a table
@subsubsection Defragmenting a Table
If there are random insertions or deletions
in the indexes of a table, the indexes
......@@ -38888,13 +39013,13 @@ not occur.
@node Error handling, InnoDB restrictions, File space management, InnoDB
@subsection Error handling
@subsection Error Handling
The error handling in InnoDB is not always the same as
specified in the ANSI SQL standards. According to the ANSI
standard, any error during an SQL statement should cause the
rollback of that statement. InnoDB sometimes rolls back only
part of the statement.
part of the statement, or the whole transaction.
The following list specifies the error handling of InnoDB.
@itemize @bullet
......@@ -38903,9 +39028,9 @@ If you run out of file space in the tablespace,
you will get the MySQL @code{'Table is full'} error
and InnoDB rolls back the SQL statement.
@item
A transaction deadlock or a timeout in a lock wait will give
@code{'Table handler error 1000000'} and InnoDB rolls back
the SQL statement.
A transaction deadlock or a timeout in a lock wait make InnoDB
to roll back
the whole transaction.
@item
A duplicate key error only rolls back the insert of that particular row,
even in a statement like @code{INSERT INTO ... SELECT ...}.
......@@ -38921,7 +39046,7 @@ they roll back the corresponding SQL statement.
@node InnoDB restrictions, InnoDB contact information, Error handling, InnoDB
@subsection Restrictions on InnoDB tables
@subsection Restrictions on InnoDB Tables
@itemize @bullet
......@@ -38937,7 +39062,7 @@ error:
CREATE TABLE T (A CHAR(20), B INT, UNIQUE (A(5))) TYPE = InnoDB;
@end example
If you create a non unique index on a prefix of a column, InnoDB will
If you create a non-unique index on a prefix of a column, InnoDB will
create an index over the whole column.
@item
@code{INSERT DELAYED} is not supported for InnoDB tables.
......@@ -38961,23 +39086,19 @@ A table cannot contain more than 1000 columns.
deletes all rows, one by one, which is not that fast. In future versions
of MySQL you can use @code{TRUNCATE} which is fast.
@item
Before dropping a database with InnoDB tables one has to drop
the individual InnoDB tables first.
@item
The default database page size in InnoDB is 16 kB. By recompiling the
code one can set it from 8 kB to 64 kB.
The maximun row length is slightly less than half of a database page
in versions <= 3.23.40 of InnoDB. Starting from source
release 3.23.41 BLOB and
TEXT columns are allowed to be < 4 GB, the total row length must also be
< 4 GB. InnoDB does not store fields whose size is <= 30 bytes on separate
< 4 GB. InnoDB does not store fields whose size is <= 128 bytes on separate
pages. After InnoDB has modified the row by storing long fields on
separate pages, the remaining length of the row must be slightly less
than half a database page.
separate pages, the remaining length of the row must be less
than half a database page. The maximun key length is 7000 bytes.
@item
The maximum data or log file size is 2 GB or 4 GB depending on how large
files your operating system supports. Support for > 4 GB files will
be added to InnoDB in a future version.
On some operating systems data files must be < 2 GB. The combined
size of log files must be < 4 GB on 32-bit computers.
@item
The maximum tablespace size is 4 billion database pages. This is also
the maximum size for a table. The minimum tablespace size is 10 MB.
......@@ -38985,7 +39106,7 @@ the maximum size for a table. The minimum tablespace size is 10 MB.
@node InnoDB contact information, , InnoDB restrictions, InnoDB
@subsection InnoDB contact information
@subsection InnoDB Contact Information
Contact information of Innobase Oy, producer of the InnoDB engine.
Website: @uref{http://www.innodb.com}. Email:
......@@ -39015,7 +39136,7 @@ Finland
* BDB characteristics:: Characteristics of @code{BDB} tables:
* BDB TODO:: Things we need to fix for BDB in the near future:
* BDB portability:: Operating systems supported by @strong{BDB}
* BDB errors:: Errors You May Get When Using BDB Tables
* BDB errors:: Errors That May Occur When Using BDB Tables
@end menu
@node BDB overview, BDB install, BDB, BDB
......@@ -39265,7 +39386,7 @@ Max OS X
@node BDB errors, , BDB portability, BDB
@subsection Errors You May Get When Using BDB Tables
@subsection Errors That May Occur When Using BDB Tables
@itemize @bullet
@item
......@@ -43728,8 +43849,8 @@ included the thread libraries on the link/compile line.
* libmysqld overview:: Overview of the Embedded MySQL Server Library
* libmysqld compiling:: Compiling Programs with @code{libmysqld}
* libmysqld restrictions:: Restrictions when Using the Embedded MySQL Server
* libmysqld options:: Using Option files with the Embedded Server
* libmysqld TODO:: Things left lo do in Embedded Server (TODO)
* libmysqld options:: Using Option Files with the Embedded Server
* libmysqld TODO:: Things left to do in Embedded Server (TODO)
* libmysqld example:: A Simple Embedded Server Example
* libmysqld licensing:: Licensing the Embedded Server
@end menu
......@@ -44133,13 +44254,301 @@ contains an Eiffel wrapper written by Michael Ravits.
@chapter Extending MySQL
@menu
* MySQL internals:: MySQL Internals
* Adding functions:: Adding New Functions to MySQL
* Adding procedures:: Adding New Procedures to MySQL
* MySQL internals:: MySQL Internals
@end menu
@node Adding functions, Adding procedures, Extending MySQL, Extending MySQL
@node MySQL internals, Adding functions, Extending MySQL, Extending MySQL
@section MySQL Internals
@cindex internals
@cindex threads
This chapter describes a lot of things that you need to know when
working on the MySQL code. If you plan to contribute to MySQL
development, want to have access to the bleeding-edge in-between
versions code, or just want to keep track of development, follow the
instructions in @xref{Installing source tree}.
If you are interested in MySQL internals, you should also subscribe
to our @code{internals} mailing list. This list is relatively low
traffic. For details on how to subscribe, please see
@ref{Mailing-list}.
All developers at MySQL AB are on the @code{internals} list and we
help other people who are working on the MySQL code. Feel free to
use this list both to ask questions about the code and to send
patches that you would like to contribute to the MySQL project!
@menu
* MySQL threads:: MySQL threads
* MySQL test suite:: MySQL test suite
@end menu
@node MySQL threads, MySQL test suite, MySQL internals, MySQL internals
@subsection MySQL Threads
The MySQL server creates the following threads:
@itemize @bullet
@item
The TCP/IP connection thread handles all connection requests and
creates a new dedicated thread to handle the authentication and
and SQL query processing for each connection.
@item
On Windows NT there is a named pipe handler thread that does the same work as
the TCP/IP connection thread on named pipe connect requests.
@item
The signal thread handles all signals. This thread also normally handles
alarms and calls @code{process_alarm()} to force timeouts on connections
that have been idle too long.
@item
If @code{mysqld} is compiled with @code{-DUSE_ALARM_THREAD}, a dedicated
thread that handles alarms is created. This is only used on some systems where
there are problems with @code{sigwait()} or if one wants to use the
@code{thr_alarm()} code in ones application without a dedicated signal
handling thread.
@item
If one uses the @code{--flush_time=#} option, a dedicated thread is created
to flush all tables at the given interval.
@item
Every connection has its own thread.
@item
Every different table on which one uses @code{INSERT DELAYED} gets its
own thread.
@item
If you use @code{--master-host}, a slave replication thread will be
started to read and apply updates from the master.
@end itemize
@code{mysqladmin processlist} only shows the connection, @code{INSERT DELAYED},
and replication threads.
@node MySQL test suite, , MySQL threads, MySQL internals
@subsection MySQL Test Suite
@cindex mysqltest, MySQL Test Suite
@cindex testing mysqld, mysqltest
Until recently, our main full-coverage test suite was based on proprietary
customer data and for that reason has not been publicly available. The only
publicly available part of our testing process consisted of the @code{crash-me}
test, a Perl DBI/DBD benchmark found in the @code{sql-bench} directory, and
miscellaneous tests located in @code{tests} directory. The lack of a
standardised publicly available test suite has made it difficult for our users,
as well developers, to do regression tests on the MySQL code. To
address this problem, we have created a new test system that is included in
the source and binary distributions starting in Version 3.23.29.
The current set of test cases doesn't test everything in MySQL, but it
should catch most obvious bugs in the SQL processing code, OS/library
issues, and is quite thorough in testing replication. Our eventual goal
is to have the tests cover 100% of the code. We welcome contributions
to our test suite. You may especially want to contribute tests that
examine the functionality critical to your system, as this will ensure
that all future MySQL releases will work well with your
applications.
@menu
* running mysqltest:: Running the MySQL Test Suite
* extending mysqltest:: Extending the MySQL Test Suite
* Reporting mysqltest bugs:: Reporting Bugs in the MySQL Test Suite
@end menu
@node running mysqltest, extending mysqltest, MySQL test suite, MySQL test suite
@subsubsection Running the MySQL Test Suite
The test system consist of a test language interpreter
(@code{mysqltest}), a shell script to run all
tests(@code{mysql-test-run}), the actual test cases written in a special
test language, and their expected results. To run the test suite on
your system after a build, type @code{make test} or
@code{mysql-test/mysql-test-run} from the source root. If you have
installed a binary distribution, @code{cd} to the install root
(eg. @code{/usr/local/mysql}), and do @code{scripts/mysql-test-run}.
All tests should succeed. If not, you should try to find out why and
report the problem if this is a bug in MySQL.
@xref{Reporting mysqltest bugs}.
If you have a copy of @code{mysqld} running on the machine where you want to
run the test suite you do not have to stop it, as long as it is not using
ports @code{9306} and @code{9307}. If one of those ports is taken, you should
edit @code{mysql-test-run} and change the values of the master and/or slave
port to one that is available.
You can run one individual test case with
@code{mysql-test/mysql-test-run test_name}.
If one test fails, you should test running @code{mysql-test-run} with
the @code{--force} option to check if any other tests fails.
@node extending mysqltest, Reporting mysqltest bugs, running mysqltest, MySQL test suite
@subsubsection Extending the MySQL Test Suite
You can use the @code{mysqltest} language to write your own test cases.
Unfortunately, we have not yet written full documentation for it - we plan to
do this shortly. You can, however, look at our current test cases and use
them as an example. The following points should help you get started:
@itemize @bullet
@item
The tests are located in @code{mysql-test/t/*.test}
@item
A test case consists of @code{;} terminated statements and is similar to the
input of @code{mysql} command line client. A statement by default is a query
to be sent to MySQL server, unless it is recognised as internal
command (eg. @code{sleep}).
@item
All queries that produce results, e.g. @code{SELECT}, @code{SHOW},
@code{EXPLAIN}, etc., must be preceded with @code{@@/path/to/result/file}. The
file must contain the expected results. An easy way to generate the result
file is to run @code{mysqltest -r < t/test-case-name.test} from
@code{mysql-test} directory, and then edit the generated result files, if
needed, to adjust them to the expected output. In that case, be very careful
about not adding or deleting any invisible characters - make sure to only
change the text and/or delete lines. If you have to insert a line, make sure
the fields are separated with a hard tab, and there is a hard tab at the end.
You may want to use @code{od -c} to make sure your text editor has not messed
anything up during edit. We, of course, hope that you will never have to edit
the output of @code{mysqltest -r} as you only have to do it when you find a
bug.
@item
To be consistent with our setup, you should put your result files in
@code{mysql-test/r} directory and name them @code{test_name.result}. If the
test produces more than one result, you should use @code{test_name.a.result},
@code{test_name.b.result}, etc.
@item
If a statement returns an error, you should on the line before the statement
specify with the @code{--error error-number}. The error number can be
a list of possible error numbers separated with @code{','}.
@item
If you are writing a replication test case, you should on the first line of
the test file, put @code{source include/master-slave.inc;}. To switch between
master and slave, use @code{connection master;} and @code{connection slave;}.
If you need to do something on an alternate connection, you can do
@code{connection master1;} for the master, and @code{connection slave1;} for
the slave.
@item
If you need to do something in a loop, you can use something like this:
@example
let $1=1000;
while ($1)
@{
# do your queries here
dec $1;
@}
@end example
@item
To sleep between queries, use the @code{sleep} command. It supports fractions
of a second, so you can do @code{sleep 1.3;}, for example, to sleep 1.3
seconds.
@item
To run the slave with additional options for your test case, put them
in the command-line format in @code{mysql-test/t/test_name-slave.opt}. For
the master, put them in @code{mysql-test/t/test_name-master.opt}.
@item
If you have a question about the test suite, or have a test case to contribute,
e-mail to @email{internals@@lists.mysql.com}. As the list does not accept
attachments, you should ftp all the relevant files to:
@uref{ftp://support.mysql.com/pub/mysql/Incoming}
@end itemize
@node Reporting mysqltest bugs, , extending mysqltest, MySQL test suite
@subsubsection Reporting Bugs in the MySQL Test Suite
If your MySQL version doesn't pass the test suite you should
do the following:
@itemize @bullet
@item
Don't send a bug report before you have found out as much as possible of
what when wrong! When you do it, please use the @code{mysqlbug} script
so that we can get information about your system and @code{MySQL}
version. @xref{Bug reports}.
@item
Make sure to include the output of @code{mysql-test-run}, as well as
contents of all @code{.reject} files in @code{mysql-test/r} directory.
@item
If a test in the test suite fails, check if the test fails also when run
by its own:
@example
cd mysql-test
mysql-test-run --local test-name
@end example
If this fails, then you should configure MySQL with
@code{--with-debug} and run @code{mysql-test-run} with the
@code{--debug} option. If this also fails send the trace file
@file{var/tmp/master.trace} to ftp://support.mysql.com/pub/mysql/secret
so that we can examine it. Please remember to also include a full
description of your system, the version of the mysqld binary and how you
compiled it.
@item
Try also to run @code{mysql-test-run} with the @code{--force} option to
see if there is any other test that fails.
@item
If you have compiled MySQL yourself, check our manual for how
to compile MySQL on your platform or, preferable, use one of
the binaries we have compiled for you at
@uref{http://www.mysql.com/downloads/}. All our standard binaries should
pass the test suite !
@item
If you get an error, like @code{Result length mismatch} or @code{Result
content mismatch} it means that the output of the test didn't match
exactly the expected output. This could be a bug in MySQL or
that your mysqld version produces slight different results under some
circumstances.
Failed test results are put in a file with the same base name as the
result file with the @code{.reject} extension. If your test case is
failing, you should do a diff on the two files. If you cannot see how
they are different, examine both with @code{od -c} and also check their
lengths.
@item
If a test fails totally, you should check the logs file in the
@code{mysql-test/var/log} directory for hints of what went wrong.
@item
If you have compiled MySQL with debugging you can try to debug this
by running @code{mysql-test-run} with the @code{--gdb} and/or @code{--debug}
options.
@xref{Making trace files}.
If you have not compiled MySQL for debugging you should probably
do that. Just specify the @code{--with-debug} options to @code{configure}!
@xref{Installing source}.
@end itemize
@node Adding functions, Adding procedures, MySQL internals, Extending MySQL
@section Adding New Functions to MySQL
@cindex functions, new
......@@ -44785,7 +45194,7 @@ absolutely necessary!
@end itemize
@node Adding procedures, MySQL internals, Adding functions, Extending MySQL
@node Adding procedures, , Adding functions, Extending MySQL
@section Adding New Procedures to MySQL
@cindex procedures, adding
......@@ -44847,291 +45256,6 @@ You can find all information about procedures by examining the following files:
@end itemize
@node MySQL internals, , Adding procedures, Extending MySQL
@section MySQL Internals
@cindex internals
@cindex threads
This chapter describes a lot of things that you need to know when
working on the MySQL code. If you plan to contribute to MySQL
development, want to have access to the bleeding-edge in-between
versions code, or just want to keep track of development, follow the
instructions in @xref{Installing source tree}. If you are interested in MySQL
internals, you should also subscribe to @email{internals@@lists.mysql.com}.
This is a relatively low traffic list, in comparison with
@email{mysql@@lists.mysql.com}.
@menu
* MySQL threads:: MySQL threads
* MySQL test suite:: MySQL test suite
@end menu
@node MySQL threads, MySQL test suite, MySQL internals, MySQL internals
@subsection MySQL Threads
The MySQL server creates the following threads:
@itemize @bullet
@item
The TCP/IP connection thread handles all connection requests and
creates a new dedicated thread to handle the authentication and
and SQL query processing for each connection.
@item
On Windows NT there is a named pipe handler thread that does the same work as
the TCP/IP connection thread on named pipe connect requests.
@item
The signal thread handles all signals. This thread also normally handles
alarms and calls @code{process_alarm()} to force timeouts on connections
that have been idle too long.
@item
If @code{mysqld} is compiled with @code{-DUSE_ALARM_THREAD}, a dedicated
thread that handles alarms is created. This is only used on some systems where
there are problems with @code{sigwait()} or if one wants to use the
@code{thr_alarm()} code in ones application without a dedicated signal
handling thread.
@item
If one uses the @code{--flush_time=#} option, a dedicated thread is created
to flush all tables at the given interval.
@item
Every connection has its own thread.
@item
Every different table on which one uses @code{INSERT DELAYED} gets its
own thread.
@item
If you use @code{--master-host}, a slave replication thread will be
started to read and apply updates from the master.
@end itemize
@code{mysqladmin processlist} only shows the connection, @code{INSERT DELAYED},
and replication threads.
@node MySQL test suite, , MySQL threads, MySQL internals
@subsection MySQL Test Suite
@cindex mysqltest, MySQL Test Suite
@cindex testing mysqld, mysqltest
Until recently, our main full-coverage test suite was based on proprietary
customer data and for that reason has not been publicly available. The only
publicly available part of our testing process consisted of the @code{crash-me}
test, a Perl DBI/DBD benchmark found in the @code{sql-bench} directory, and
miscellaneous tests located in @code{tests} directory. The lack of a
standardised publicly available test suite has made it difficult for our users,
as well developers, to do regression tests on the MySQL code. To
address this problem, we have created a new test system that is included in
the source and binary distributions starting in Version 3.23.29.
The current set of test cases doesn't test everything in MySQL, but it
should catch most obvious bugs in the SQL processing code, OS/library
issues, and is quite thorough in testing replication. Our eventual goal
is to have the tests cover 100% of the code. We welcome contributions
to our test suite. You may especially want to contribute tests that
examine the functionality critical to your system, as this will ensure
that all future MySQL releases will work well with your
applications.
@menu
* running mysqltest:: Running the MySQL Test Suite
* extending mysqltest:: Extending the MySQL Test Suite
* Reporting mysqltest bugs:: Reporting Bugs in the MySQL Test Suite
@end menu
@node running mysqltest, extending mysqltest, MySQL test suite, MySQL test suite
@subsubsection Running the MySQL Test Suite
The test system consist of a test language interpreter
(@code{mysqltest}), a shell script to run all
tests(@code{mysql-test-run}), the actual test cases written in a special
test language, and their expected results. To run the test suite on
your system after a build, type @code{make test} or
@code{mysql-test/mysql-test-run} from the source root. If you have
installed a binary distribution, @code{cd} to the install root
(eg. @code{/usr/local/mysql}), and do @code{scripts/mysql-test-run}.
All tests should succeed. If not, you should try to find out why and
report the problem if this is a bug in MySQL.
@xref{Reporting mysqltest bugs}.
If you have a copy of @code{mysqld} running on the machine where you want to
run the test suite you do not have to stop it, as long as it is not using
ports @code{9306} and @code{9307}. If one of those ports is taken, you should
edit @code{mysql-test-run} and change the values of the master and/or slave
port to one that is available.
You can run one individual test case with
@code{mysql-test/mysql-test-run test_name}.
If one test fails, you should test running @code{mysql-test-run} with
the @code{--force} option to check if any other tests fails.
@node extending mysqltest, Reporting mysqltest bugs, running mysqltest, MySQL test suite
@subsubsection Extending the MySQL Test Suite
You can use the @code{mysqltest} language to write your own test cases.
Unfortunately, we have not yet written full documentation for it - we plan to
do this shortly. You can, however, look at our current test cases and use
them as an example. The following points should help you get started:
@itemize @bullet
@item
The tests are located in @code{mysql-test/t/*.test}
@item
A test case consists of @code{;} terminated statements and is similar to the
input of @code{mysql} command line client. A statement by default is a query
to be sent to MySQL server, unless it is recognised as internal
command (eg. @code{sleep}).
@item
All queries that produce results, e.g. @code{SELECT}, @code{SHOW},
@code{EXPLAIN}, etc., must be preceded with @code{@@/path/to/result/file}. The
file must contain the expected results. An easy way to generate the result
file is to run @code{mysqltest -r < t/test-case-name.test} from
@code{mysql-test} directory, and then edit the generated result files, if
needed, to adjust them to the expected output. In that case, be very careful
about not adding or deleting any invisible characters - make sure to only
change the text and/or delete lines. If you have to insert a line, make sure
the fields are separated with a hard tab, and there is a hard tab at the end.
You may want to use @code{od -c} to make sure your text editor has not messed
anything up during edit. We, of course, hope that you will never have to edit
the output of @code{mysqltest -r} as you only have to do it when you find a
bug.
@item
To be consistent with our setup, you should put your result files in
@code{mysql-test/r} directory and name them @code{test_name.result}. If the
test produces more than one result, you should use @code{test_name.a.result},
@code{test_name.b.result}, etc.
@item
If a statement returns an error, you should on the line before the statement
specify with the @code{--error error-number}. The error number can be
a list of possible error numbers separated with @code{','}.
@item
If you are writing a replication test case, you should on the first line of
the test file, put @code{source include/master-slave.inc;}. To switch between
master and slave, use @code{connection master;} and @code{connection slave;}.
If you need to do something on an alternate connection, you can do
@code{connection master1;} for the master, and @code{connection slave1;} for
the slave.
@item
If you need to do something in a loop, you can use something like this:
@example
let $1=1000;
while ($1)
@{
# do your queries here
dec $1;
@}
@end example
@item
To sleep between queries, use the @code{sleep} command. It supports fractions
of a second, so you can do @code{sleep 1.3;}, for example, to sleep 1.3
seconds.
@item
To run the slave with additional options for your test case, put them
in the command-line format in @code{mysql-test/t/test_name-slave.opt}. For
the master, put them in @code{mysql-test/t/test_name-master.opt}.
@item
If you have a question about the test suite, or have a test case to contribute,
e-mail to @email{internals@@lists.mysql.com}. As the list does not accept
attachments, you should ftp all the relevant files to:
@uref{ftp://support.mysql.com/pub/mysql/Incoming}
@end itemize
@node Reporting mysqltest bugs, , extending mysqltest, MySQL test suite
@subsubsection Reporting Bugs in the MySQL Test Suite
If your MySQL version doesn't pass the test suite you should
do the following:
@itemize @bullet
@item
Don't send a bug report before you have found out as much as possible of
what when wrong! When you do it, please use the @code{mysqlbug} script
so that we can get information about your system and @code{MySQL}
version. @xref{Bug reports}.
@item
Make sure to include the output of @code{mysql-test-run}, as well as
contents of all @code{.reject} files in @code{mysql-test/r} directory.
@item
If a test in the test suite fails, check if the test fails also when run
by its own:
@example
cd mysql-test
mysql-test-run --local test-name
@end example
If this fails, then you should configure MySQL with
@code{--with-debug} and run @code{mysql-test-run} with the
@code{--debug} option. If this also fails send the trace file
@file{var/tmp/master.trace} to ftp://support.mysql.com/pub/mysql/secret
so that we can examine it. Please remember to also include a full
description of your system, the version of the mysqld binary and how you
compiled it.
@item
Try also to run @code{mysql-test-run} with the @code{--force} option to
see if there is any other test that fails.
@item
If you have compiled MySQL yourself, check our manual for how
to compile MySQL on your platform or, preferable, use one of
the binaries we have compiled for you at
@uref{http://www.mysql.com/downloads/}. All our standard binaries should
pass the test suite !
@item
If you get an error, like @code{Result length mismatch} or @code{Result
content mismatch} it means that the output of the test didn't match
exactly the expected output. This could be a bug in MySQL or
that your mysqld version produces slight different results under some
circumstances.
Failed test results are put in a file with the same base name as the
result file with the @code{.reject} extension. If your test case is
failing, you should do a diff on the two files. If you cannot see how
they are different, examine both with @code{od -c} and also check their
lengths.
@item
If a test fails totally, you should check the logs file in the
@code{mysql-test/var/log} directory for hints of what went wrong.
@item
If you have compiled MySQL with debugging you can try to debug this
by running @code{mysql-test-run} with the @code{--gdb} and/or @code{--debug}
options.
@xref{Making trace files}.
If you have not compiled MySQL for debugging you should probably
do that. Just specify the @code{--with-debug} options to @code{configure}!
@xref{Installing source}.
@end itemize
@node Problems, Users, Extending MySQL, Top
@appendix Problems and Common Errors
......@@ -45140,7 +45264,7 @@ do that. Just specify the @code{--with-debug} options to @code{configure}!
@menu
* What is crashing:: How to determine what is causing problems
* Common errors:: Common errors when using MySQL
* Common errors:: Common Errors When Using MySQL
* Installation Issues:: Installation Related Issues
* Administration Issues:: Administration Related Issues
* Query Issues:: Query Related Issues
......@@ -48409,14 +48533,15 @@ record format.
Win32 port with Borland compiler. @code{mysqlshutdown.exe} and
@code{mysqlwatch.exe}
@item David J. Hughes
For the effort to make a shareware SQL database. We at TcX started with
@code{mSQL}, but found that it couldn't satisfy our purposes so instead we
wrote a SQL interface to our application builder Unireg. @code{mysqladmin}
and @code{mysql} are programs that were largely influenced by their
@code{mSQL} counterparts. We have put a lot of effort into making the
MySQL syntax a superset of @code{mSQL}. Many of the API's ideas are
borrowed from @code{mSQL} to make it easy to port free @code{mSQL} programs
to MySQL. MySQL doesn't contain any code from @code{mSQL}.
For the effort to make a shareware SQL database. At TcX, the predecessor
of MySQL AB, we started with @code{mSQL}, but found that it couldn't
satisfy our purposes so instead we wrote a SQL interface to our
application builder Unireg. @code{mysqladmin} and @code{mysql} ar
programs that were largely influenced by their @code{mSQL} counterparts.
We have put a lot of effort into making the MySQL syntax a superset of
@code{mSQL}. Many of the API's ideas are borrowed from @code{mSQL} to
make it easy to port free @code{mSQL} programs to MySQL.
MySQL doesn't contain any code from @code{mSQL}.
Two files in the distribution (@file{client/insert_test.c} and
@file{client/select_test.c}) are based on the corresponding (non-copyrighted)
files in the @code{mSQL} distribution, but are modified as examples showing
......@@ -48435,7 +48560,7 @@ From whom we got an excellent compiler (@code{gcc}), the @code{libc} library
and the @code{readline} library (for the @code{mysql} client).
@item Free Software Foundation & The XEmacs development team
For a really great editor/environment used by almost everybody at
TcX/MySQL AB/detron.
MySQL AB/TcX/detron.
@item Patrick Lynch
For helping us acquire @uref{http://www.mysql.com/}.
@item Fred Lindberg
include/violite.h
View file @ 2050505f
......@@ -102,9 +102,6 @@ my_bool vio_peer_addr(Vio* vio, char *buf);
void vio_in_addr(Vio *vio, struct in_addr *in);
/* Return 1 if there is data to be read */
my_bool vio_poll_read(Vio *vio,uint timeout);
#ifdef __cplusplus
}
#endif
......@@ -122,7 +119,6 @@ my_bool vio_poll_read(Vio *vio,uint timeout);
#define vio_close(vio) ((vio)->vioclose)(vio)
#define vio_peer_addr(vio, buf) (vio)->peer_addr(vio, buf)
#define vio_in_addr(vio, in) (vio)->in_addr(vio, in)
#define vio_poll_read(vio,timeout) (vio)->poll_read(vio,timeout)
#endif /* defined(HAVE_VIO) && !defined(DONT_MAP_VIO) */
#ifdef HAVE_OPENSSL
......@@ -155,9 +151,6 @@ int vio_ssl_errno(Vio *vio);
my_bool vio_ssl_peer_addr(Vio* vio, char *buf);
void vio_ssl_in_addr(Vio *vio, struct in_addr *in);
/* Return 1 if there is data to be read */
my_bool vio_ssl_poll_read(Vio *vio,uint timeout);
/* Single copy for server */
struct st_VioSSLAcceptorFd
{
......@@ -227,7 +220,6 @@ struct st_vio
void (*in_addr)(Vio*, struct in_addr*);
my_bool (*should_retry)(Vio*);
int (*vioclose)(Vio*);
my_bool (*poll_read)(Vio*,uint);
#ifdef HAVE_OPENSSL
SSL* ssl_;
......
vio/vio.c
View file @ 2050505f
......@@ -60,7 +60,6 @@ void vio_reset(Vio* vio, enum enum_vio_type type,
vio->vioclose =vio_ssl_close;
vio->peer_addr =vio_ssl_peer_addr;
vio->in_addr =vio_ssl_in_addr;
vio->poll_read =vio_ssl_poll_read;
vio->vioblocking =vio_blocking;
vio->is_blocking =vio_is_blocking;
}
......@@ -77,7 +76,6 @@ void vio_reset(Vio* vio, enum enum_vio_type type,
vio->vioclose =vio_close;
vio->peer_addr =vio_peer_addr;
vio->in_addr =vio_in_addr;
vio->poll_read =vio_poll_read;
vio->vioblocking =vio_blocking;
vio->is_blocking =vio_is_blocking;
}
......
vio/viossl.c
View file @ 2050505f
......@@ -255,32 +255,11 @@ void vio_ssl_in_addr(Vio *vio, struct in_addr *in)
}
/* Return 0 if there is data to be read */
my_bool vio_ssl_poll_read(Vio *vio,uint timeout)
{
#ifndef HAVE_POLL
return 0;
#else
struct pollfd fds;
int res;
DBUG_ENTER("vio_ssl_poll");
fds.fd=vio->sd;
fds.events=POLLIN;
fds.revents=0;
if ((res=poll(&fds,1,(int) timeout*1000)) <= 0)
{
DBUG_RETURN(res < 0 ? 0 : 1); /* Don't return 1 on errors */
}
DBUG_RETURN(fds.revents & POLLIN ? 0 : 1);
#endif
}
void sslaccept(struct st_VioSSLAcceptorFd* ptr, Vio* vio, long timeout)
{
X509* client_cert;
char *str;
char buf[1024];
X509* client_cert;
DBUG_ENTER("sslaccept");
DBUG_PRINT("enter", ("sd=%d ptr=%p", vio->sd,ptr));
vio_reset(vio,VIO_TYPE_SSL,vio->sd,0,FALSE);
......@@ -339,7 +318,6 @@ void sslconnect(struct st_VioSSLConnectorFd* ptr, Vio* vio, long timeout)
DBUG_ENTER("sslconnect");
DBUG_PRINT("enter", ("sd=%d ptr=%p ctx: %p", vio->sd,ptr,ptr->ssl_context_));
vio_reset(vio,VIO_TYPE_SSL,vio->sd,0,FALSE);
vio->ssl_=0;
vio->open_=FALSE;
if (!(vio->ssl_ = SSL_new(ptr->ssl_context_)))
......
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