Altering/updating table schemas

TimescaleDB supports using the ALTER TABLE command to modify the schema of the hypertable. A change to the hypertable schema results in changes to the schema of each underlying chunk.

This change can be a potentially expensive operation if it requires a rewrite of the underlying data. However, a common modification is to add a field with a default value of NULL (if no DEFAULT clause is specified, then the default will be NULL); such a schema modification is inexpensive. More details can be found in the Notes section of the PostgreSQL documentation on ALTER TABLE.