Oracle 5.0 Reference Manual page 529

Conversely, the second of the following lines is legal at runtime, but the first is not:
mysql> SET GLOBAL max_allowed_packet=16M;
mysql> SET GLOBAL max_allowed_packet=16*1024*1024;
Note
Some system variables can be enabled with the
them to
a variable on the command line or in an option file, you must set it to
setting it to
delay_key_write=1
does not.
To display system variable names and values, use the
mysql> SHOW VARIABLES;
+--------+--------------------------------------------------------------+
| Variable_name
+--------+--------------------------------------------------------------+
| auto_increment_increment
| auto_increment_offset
| automatic_sp_privileges
| back_log
| basedir
| bdb_cache_size
| bdb_home
| bdb_log_buffer_size
| bdb_logdir
| bdb_max_lock
| bdb_shared_data
| bdb_tmpdir
| binlog_cache_size
| bulk_insert_buffer_size
| character_set_client
| character_set_connection
| character_set_database
| character_set_results
| character_set_server
| character_set_system
| character_sets_dir
| collation_connection
| collation_database
| collation_server
...
| innodb_additional_mem_pool_size | 1048576
| innodb_autoextend_increment
| innodb_buffer_pool_awe_mem_mb
| innodb_buffer_pool_size
| innodb_checksums
| innodb_commit_concurrency
| innodb_concurrency_tickets
| innodb_data_file_path
| innodb_data_home_dir
...
| version
| version_comment
| version_compile_machine
| version_compile_os
| wait_timeout
+--------+--------------------------------------------------------------+
With a [896] clause, the statement displays only those variables that match the pattern. To
LIKE
obtain a specific variable name, use a
SHOW VARIABLES LIKE 'max_join_size';
SHOW SESSION VARIABLES LIKE 'max_join_size';
To get a list of variables whose name match a pattern, use the "%" wildcard character in a
clause:
Using System Variables
or 1, or disabled by setting them to
ON
or will not work. For example, on the command line,
ON OFF
[447] works but
| Value
| 1
| 1
| ON
| 50
| /
| 8388600
| /var/lib/mysql/
| 32768
|
| 10000
| OFF
| /tmp/
| 32768
| 8388608
| latin1
| latin1
| latin1
| latin1
| latin1
| utf8
| /usr/share/mysql/charsets/
| latin1_swedish_ci
| latin1_swedish_ci
| latin1_swedish_ci
| 8
| 0
| 8388608
| ON
| 0
| 500
| ibdata1:10M:autoextend
|
| 5.0.19
| MySQL Community Edition - (GPL)
| i686
| pc-linux-gnu
| 28800
[896]
LIKE
509
statement by setting
SET
or 0. However, to set such
OFF
--delay_key_write=ON
SHOW VARIABLES
clause as shown:
or 0;
1
--
[447]
statement:
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[896]
LIKE