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SHOW VARIABLES
Shows a list of variable bindings.
Syntax
SHOW [CLUSTER] [LOCAL|GLOBAL] VARIABLES [EXTENDED]
[LIKE 'pattern' | WHERE expression]
Arguments
pattern
- Can contain the%
wildcard which represents zero or more characters. Can also contain the_
wildcard which represents one character.expression
- A SQLWHERE
clause.
Remarks
CLUSTER
- Displays the list of variables that can sync to all nodes._SYNC
andCLUSTER
are synonymous. Use either of the options in the command.LOCAL
- Displays the list of variable bindings in the current connection to the node. This includes the values of global variables that have been set. Values of session variables that can be set globally are not included, when these variables are set globally.SESSION
andLOCAL
are synonymous. Use either of the options in the command.GLOBAL
- Displays the list of global variable bindings. Values of session variables that can be set globally are also included, when these variables are set globally.- If the
_SYNC|CLUSTER
option is specified,GLOBAL
variables are shown by default. - If the
_SYNC|CLUSTER
option is not specified,LOCAL
variables are shown by default. EXTENDED
- Displays additional information about the variables in the output:Variable_type
- Displays the type of sync variable. For non-sync variables and session variables that can also be set globally, the value isLocal
.Cluster_type
- If the variable is global, has the same value asVariable_type
. If the variable is a session variable that can also be set globally, displays the type of sync variable. If the variable is not a sync variable, the value isLocal
.
- This command can be run on any SingleStore node (see Node Requirements for SingleStore DB Commands).
Examples
Using SHOW VARIABLES
with a Wildcard
SHOW VARIABLES LIKE 'auto%';
****
+--------------------------+-------+
| Variable_name | Value |
+--------------------------+-------+
| auto_attach | ON |
| auto_increment_increment | 1 |
| auto_increment_offset | 1 |
| auto_replicate | OFF |
| autocommit | ON |
+--------------------------+-------+
Behavior of SHOW LOCAL VARIABLES
When a Global Variable is Set
When a global variable is set, its value becomes effective in the current connection to the node. For this reason, after setting the global variable connect_timeout
to 20
, this value is shown in the SHOW LOCAL VARIABLES
output:
SET GLOBAL connect_timeout = 20;
SHOW LOCAL VARIABLES LIKE 'connect_timeout';
****
+-----------------+-------+
| Variable_name | Value |
+-----------------+-------+
| connect_timeout | 20 |
+-----------------+-------+
Behavior of SHOW LOCAL VARIABLES
When a Session Variable that can be Set Globally is Set
When a session variable that can also be set globally is set globally, its value is not effective in the current connection to the node. For this reason, after setting the variable enable_broadcast_left_join
to OFF
, the value is not shown in the SHOW LOCAL VARIABLES
output:
SET GLOBAL enable_broadcast_left_join = OFF;
SHOW LOCAL VARIABLES LIKE 'enable_broadcast_left_join';
****
+----------------------------+-------+
| Variable_name | Value |
+----------------------------+-------+
| enable_broadcast_left_join | ON |
+----------------------------+-------+
Using the EXTENDED
Clause
In this example, the value of Variable_type
is Local
because character_set_server
is a session variable that can be set globally. The value of Cluster_type
is not Local
because character_set_server
is a sync variable.
SHOW VARIABLES EXTENDED LIKE 'character_set_server';
****
+----------------------+-------+---------------+----------------------------+
| Variable_name | Value | Variable_type | Cluster_type |
+----------------------+-------+---------------+----------------------------+
| character_set_server | utf8 | Local | Cluster-wide for all nodes |
+----------------------+-------+---------------+----------------------------+