Behavior Change Management¶

Overview¶

Snowflake implements behavior changes monthly in bundles included in regularly-scheduled releases. During the testing period and opt-out period for each behavior change bundle, you can enable or disable the bundle in your account. This document explains how to check whether a particular bundle is enabled in your account and how to enable or disable it.

In this document, bundle_name is the name of the behavior change bundle in the form YYYY_NN, found in the Behavior Change Log.

Checking the Status of a Behavior Change Bundle in Your Account¶

To check whether a specific behavior change bundle is enabled in your account, use the SYSTEM$BEHAVIOR_CHANGE_BUNDLE_STATUS function with the bundle_name as the argument:

SELECT SYSTEM$BEHAVIOR_CHANGE_BUNDLE_STATUS('2021_02');

+-------------------------------------------------+
| SYSTEM$BEHAVIOR_CHANGE_BUNDLE_STATUS('2021_02') |
|-------------------------------------------------|
| DISABLED                                        |
+-------------------------------------------------+

Copy

Enabling a Behavior Change Bundle in Your Account¶

To enable a particular behavior change in your account, use the SYSTEM$ENABLE_BEHAVIOR_CHANGE_BUNDLE function and specify the bundle_name that contains the change:

SELECT SYSTEM$ENABLE_BEHAVIOR_CHANGE_BUNDLE('2021_02');

+-------------------------------------------------+
| SYSTEM$ENABLE_BEHAVIOR_CHANGE_BUNDLE('2021_02') |
|-------------------------------------------------|
| ENABLED                                         |
+-------------------------------------------------+

Copy

Disabling a Behavior Change Bundle in Your Account¶

To disable a particular behavior change in your account, use the SYSTEM$DISABLE_BEHAVIOR_CHANGE_BUNDLE function and specify the bundle_name that contains the change:

SELECT SYSTEM$DISABLE_BEHAVIOR_CHANGE_BUNDLE('2021_02');

+-------------------------------------------------+
| SYSTEM$DISABLE_BEHAVIOR_CHANGE_BUNDLE('2021_02')|
|-------------------------------------------------|
| DISABLED                                        |
+-------------------------------------------------+

Copy

Mitigating Masking Policy Return Value Updates¶

In a future behavior change release bundle, Snowflake plans to return values for length, precision, and scale in masking policy conditions (collectively: “return value updates”). When these return value updates are made, a query on a column protected by a masking policy fails when the following are true:

• The bundle is enabled.

• The masking policy conditions return a value whose length, scale, or precision is greater than the length, scale, or precision of the column to which the masking policy is assigned. For example:

  Create a policy:

  CREATE MASKING POLICY MP AS (s string)
  RETURNS STRING -> 'abcdef';
  

  Copy

  Assign the policy:

  CREATE TABLE t(col1 string(2));
  
  ALTER TABLE t MODIFY COLUMN col1 SET MASKING POLICY mp;
  

  Copy

  Query the column (fails):

  SELECT * FROM t;
  

  Copy

To determine the impact of this change and provide enough time to update the masking policy conditions to protect data, query the SNOWFLAKE.BCR_ROLLOUT.BCR_2022_07_DDM_ROLLOUT view to understand how the future return value updates affect your account.

The BCR_2022_07_DDM_ROLLOUT view is temporary. Snowflake will remove the view when the return value updates are generally enabled in a future behavior change bundle. At this point, you will not be able to query the view to determine affected columns and policies or prevent column query or masking policy assignment operation failures due to return value updates.