The SET
statement can modify one of the session configuration variables. These can also be queried via SHOW
.
SET
statements are lost. It is therefore more reliable to configure the session in the client's connection string. For examples in different languages, see the Build an App with CockroachDB tutorials.Required Privileges
No privileges are required to modify the session settings.
Synopsis
SET
statement for session settings is unrelated to the other SET TRANSACTION
and SET CLUSTER SETTING
statements.Parameters
The SET <session variable>
statement accepts two parameters: the
variable name and the value to use to modify the variable.
The variable name is case insensitive. The value can be a list of one or more items. For example, the variable search_path
is multi-valued.
Supported Variables
Variable name | Description | Initial value | Can be viewed with SHOW ? |
---|---|---|---|
application_name |
The current application name for statistics collection. | Empty string | Yes |
database |
The current database. | Database in connection string, or empty if not specified | Yes |
default_transaction_isolation |
New in v2.0: The default transaction isolation level for the current session. See Transaction parameters and SET TRANSACTION for more details. |
Settings in connection string, or "SERIALIZABLE " if not specified |
Yes |
default_transaction_read_only |
The default transaction access mode for the current session. If set to on , only read operations are allowed in transactions in the current session; if set to off , both read and write operations are allowed. See SET TRANSACTION for more details. |
off |
Yes |
sql_safe_updates |
If true , disallow potentially unsafe SQL statements, including DELETE without a WHERE clause, UPDATE without a WHERE clause, and ALTER TABLE ... DROP COLUMN . See Allow Potentially Unsafe SQL Statements for more details. |
true for interactive sessions from the built-in SQL client unless --safe-updates=false is specified,false for sessions from other clients |
Yes |
search_path |
Changed in v2.0: A list of schemas that will be searched to resolve unqualified table or function names. For more details, see Name Resolution. | "{public} " |
Yes |
server_version_num |
New in v2.0: The version of PostgreSQL that CockroachDB emulates. | Version-dependent | Yes |
timezone |
The default time zone for the current session. This value can be a string representation of a local system-defined time zone (e.g., 'EST' , 'America/New_York' ) or a positive or negative numeric offset from UTC (e.g., -7 , +7 ). Also, DEFAULT , LOCAL , or 0 sets the session time zone to UTC .See Setting the Time Zone for more details. Changed in v2.0: This session variable was named "time zone" (with a space) in CockroachDB 1.x. It has been renamed for compatibility with PostgreSQL. |
UTC |
Yes |
tracing |
The trace recording state. See SET TRACING for more details. |
off |
Yes |
transaction_isolation |
The isolation level of the current transaction. See Transaction parameters for more details. Changed in v2.0: This session variable was called transaction isolation level (with spaces) in CockroachDB 1.x. It has been renamed for compatibility with PostgreSQL. |
SERIALIZABLE |
Yes |
transaction_priority |
The priority of the current transaction. See Transaction parameters for more details. Changed in v2.0: This session variable was called transaction priority (with a space) in CockroachDB 1.x. It has been renamed for compatibility with PostgreSQL. |
NORMAL |
Yes |
transaction_read_only |
New in v2.0: The access mode of the current transaction. See Set Transaction for more details. | off |
Yes |
transaction_status |
The state of the current transaction. See Transactions for more details. Changed in v2.0: This session variable was called transaction status (with a space) in CockroachDB 1.x. It has been renamed for compatibility with PostgreSQL. |
NoTxn |
Yes |
client_encoding |
Ignored; recognized for compatibility with PostgreSQL clients. Only possible value is "UTF8 ". |
N/A | No |
client_min_messages |
Ignored; recognized for compatibility with PostgreSQL clients. Only possible value is "on ". |
N/A | No |
extra_float_digits |
Ignored; recognized for compatibility with PostgreSQL clients. | N/A | No |
standard_conforming_strings |
Ignored; recognized for compatibility with PostgreSQL clients. | N/A | No |
Special syntax cases:
Syntax | Equivalent to | Notes |
---|---|---|
USE ... |
SET database = ... |
This is provided as convenience for users with a MySQL/MSSQL background. |
SET NAMES ... |
SET client_encoding = ... |
This is provided for compatibility with PostgreSQL clients. |
SET SESSION CHARACTERISTICS AS TRANSACTION ISOLATION LEVEL ... |
SET default_transaction_isolation = ... |
This is provided for compatibility with standard SQL. |
SET TIME ZONE ... |
SET timezone = ... |
This is provided for compatibility with PostgreSQL clients. |
Examples
Set Simple Variables
The following demonstrates how SET
can be used to configure the
default database for the current session:
> SET database = bank;
> SHOW database;
+----------+
| database |
+----------+
| bank |
+----------+
(1 row)
Set Variables to Values Containing Spaces
The following demonstrates how to use quoting to use values containing spaces:
> SET database = "database name with spaces";
> SHOW database;
+---------------------------+
| database |
+---------------------------+
| database name with spaces |
+---------------------------+
(1 row)
Set Variables to a List of Values
The following demonstrates how to assign a list of values:
> SET search_path = pg_catalog,public;
> SHOW search_path;
+---------------------------+
| search_path |
+---------------------------+
| pg_catalog, public |
+---------------------------+
(1 row)
Reset a Variable to Its Default Value
RESET
to reset a session variable as well.> SET default_transaction_isolation = SNAPSHOT;
> SHOW default_transaction_isolation;
+-------------------------------+
| default_transaction_isolation |
+-------------------------------+
| SNAPSHOT |
+-------------------------------+
(1 row)
> SET default_transaction_isolation = DEFAULT;
> SHOW default_transaction_isolation;
+-------------------------------+
| default_transaction_isolation |
+-------------------------------+
| SERIALIZABLE |
+-------------------------------+
(1 row)
SET TIME ZONE
You can control your client's default time zone for the current session with SET TIME ZONE
. This will apply a session offset to all TIMESTAMP WITH TIME ZONE
values.
SET TIME ZONE
, CockroachDB uses UTC as the default time zone.Parameters
The time zone value indicates the time zone for the current session.
This value can be a string representation of a local system-defined
time zone (e.g., 'EST'
, 'America/New_York'
) or a positive or
negative numeric offset from UTC (e.g., -7
, +7
). Also, DEFAULT
,
LOCAL
, or 0
sets the session time zone to UTC
.
Example: Set the Default Time Zone via SET TIME ZONE
> SET TIME ZONE 'EST'; -- same as SET "timezone" = 'EST'
> SHOW TIME ZONE;
+-----------+
| time zone |
+-----------+
| EST |
+-----------+
(1 row)
> SET TIME ZONE DEFAULT; -- same as SET "timezone" = DEFAULT
> SHOW TIME ZONE;
+-----------+
| time zone |
+-----------+
| UTC |
+-----------+
(1 row)
SET TRACING
SET TRACING
changes the trace recording state of the current session. A trace recording can be inspected with the SHOW TRACE FOR SESSION
statement.
Value | Description |
---|---|
off |
Trace recording is disabled. |
cluster |
Trace recording is enabled; distributed traces are collected. |
on |
Same as cluster . |
kv |
Same as cluster except that "kv messages" are collected instead of regular trace messages. See SHOW TRACE . |
local |
Trace recording is enabled; only trace messages issued by the local node are collected. |