May 28, 2026: Dynamic tables immutability constraints renamed to frozen regions¶
The dynamic tables feature formerly known as the immutability constraint is now called the
frozen region of a dynamic table. As part of this rename, the IMMUTABLE WHERE clause is
also renamed to FROZEN WHERE.
The terminology changes are as follows:
| Old | New |
|---|---|
| Immutability constraint (feature name) | Frozen region of a dynamic table |
IMMUTABLE WHERE (SQL keyword) | FROZEN WHERE |
| Immutable region | Frozen region |
| Mutable region | Active region |
METADATA$IS_IMMUTABLE (metadata column) | METADATA$IS_FROZEN |
The rename is backward compatible. The IMMUTABLE WHERE keyword still works in CREATE DYNAMIC TABLE
and ALTER DYNAMIC TABLE, the METADATA$IS_IMMUTABLE metadata column still works, and existing
dynamic tables don’t need any changes.
For more information, see Frozen regions and backfill, CREATE DYNAMIC TABLE, and ALTER DYNAMIC TABLE.