SET {session variable}

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The SET statement can modify one of the session configuration variables. These can also be queried via SHOW. By default, session variable values are set for the duration of the current session.

CockroachDB supports setting session variables for the duration of a single transaction, using the LOCAL keyword.

Required privileges

To set the role session variable, the current user must be a member of the admin role, or a member of the target role.

All other session variables do not require privileges to modify.

Synopsis

The SET statement can set a session variable for the duration of the current session (SET {variable}/SET SESSION {variable}), or for the duration of a single transaction (SET LOCAL {variable}).

SET SESSION

SET LOCAL

Parameters

Supported variables

The following session variables are exposed only for backwards compatibility with earlier CockroachDB releases and have no impact on how CockroachDB runs:

Special syntax cases

CockroachDB supports the following syntax cases, for compatibility with common SQL syntax patterns:

Examples

Set simple variables

The following examples demonstrate how to use SET to configure the default database for the current session:

SET application_name = movr_app;

SHOW application_name;

  application_name
--------------------
  movr_app
(1 row)

Set variables to values containing spaces

The following demonstrates how to use quoting to use values containing spaces:

SET application_name = "movr app";

SHOW application_name;

  application_name
--------------------
  movr app
(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

SHOW search_path;

     search_path
----------------------
  pg_catalog, public
(1 row)

SET search_path = DEFAULT;

SHOW search_path;

    search_path
-------------------
  "$user", public
(1 row)

Set a variable for the duration of a single transaction

To set a variable for the duration of a single transaction, use the SET LOCAL statement.

SHOW application_name;

  application_name
--------------------
  movr app
(1 row)

BEGIN;
SET LOCAL application_name = demo;
SHOW application_name;

  application_name
--------------------
  demo
(1 row)

COMMIT;
SHOW application_name;

  application_name
--------------------
  movr app
(1 row)

Roll back session variables set for a transaction

You can roll back session variable settings to savepoints.

SHOW timezone;

  timezone
------------
  UTC
(1 row)

BEGIN;
SET timezone = '+3';
SAVEPOINT s1;
SHOW timezone;

  timezone
------------
  +3
(1 row)

SET LOCAL timezone = '+1';
SHOW timezone;

  timezone
------------
  +1
(1 row)

ROLLBACK TO SAVEPOINT s1;
SHOW timezone;

  timezone
------------
  +3
(1 row)

COMMIT;
SHOW timezone;

  timezone
------------
  +3
(1 row)

Assume another role

To assume another role for the duration of a session, use SET ROLE <role>. SET ROLE <role> is equivalent to SET role = <role>.

SHOW role;

  role
--------
  root
(1 row)

CREATE ROLE new_role;
SHOW ROLES;

  username | options | member_of
-----------+---------+------------
  admin    |         | {}
  new_role | NOLOGIN | {}
  root     |         | {admin}
(3 rows)

SET ROLE new_role;
SHOW role;

    role
------------
  new_role
(1 row)

To reset the role of the current user, use a RESET statement. RESET ROLE is equivalent to SET role = 'none' and SET role = current_user().

RESET ROLE;
SHOW role;

  role
--------
  root
(1 row)

To assume a role for the duration of a single transaction, use SET LOCAL ROLE.

BEGIN;
SET LOCAL ROLE new_role;
SHOW role;

    role
------------
  new_role
(1 row)

COMMIT;
SHOW role;

  role
--------
  root
(1 row)

SET TIME ZONE

You can control the default time zone for a session with SET TIME ZONE. This will apply an offset to all TIMESTAMPTZ/TIMESTAMP WITH TIME ZONE and TIMETZ/TIME WITH TIME ZONE values in the session. By default, CockroachDB uses UTC as the time zone for SET TIME ZONE offsets.

Parameters

The input passed to SET TIME ZONE 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, or UTC-7, UTC+7) or GMT (e.g., GMT-7, GMT+7). The numeric offset input can also be colon-delimited (e.g., -7:00, GMT+7:00).

When setting a time zone, note the following:

• Timezone abbreviations are case-insensitive.

• To see a list of supported timezones, their nicknames, and their offsets, run the following query:

  SELECT * FROM pg_timezone_names;

• DEFAULT, LOCAL, or 0 sets the session time zone to UTC.

• Only offsets specified by integers (e.g., -7, 7) use the ISO 8601 time offset (i.e., the offset input is parsed as hours east of UTC). If you explicitly specify UTC or GMT for the time zone offset (e.g., UTC-7,GMT+7), or if the numeric input is colon-delimited (e.g., -7:00, GMT+7:00), CockroachDB uses the POSIX time offset instead (i.e., hours west of the specified time zone). This means that specifying an offset of -7 (i.e., -7 east of UTC) is equivalent to specifying GMT+7 (i.e., 7 west of UTC).

Example: Set the default time zone via SET TIME ZONE

> SET TIME ZONE 'EST'; -- same as SET "timezone" = 'EST'

> SHOW TIME ZONE;

  timezone
+----------+
  EST
(1 row)

> SET TIME ZONE DEFAULT; -- same as SET "timezone" = DEFAULT

> SHOW TIME ZONE;

  timezone
+----------+
  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.

Known Limitations

SET does not properly apply ROLLBACK within a transaction. For example, in the following transaction, showing the TIME ZONE variable does not return 2 as expected after the rollback:

SET TIME ZONE +2;
BEGIN;
SET TIME ZONE +3;
ROLLBACK;
SHOW TIME ZONE;

timezone
------------
3

Tracking GitHub Issue

See also

• RESET
• SET TRANSACTION
• SET CLUSTER SETTING
• SHOW {session variable}
• The TIMESTAMP and TIMESTAMPTZ data types.
• SHOW TRACE FOR SESSION
• pg_catalog

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