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Schema modifications

You can modify the schema of compressed hypertables in recent versions of TimescaleDB.

Schema modificationBefore TimescaleDB 2.1TimescaleDB 2.1 to 2.5TimescaleDB 2.6 and above
Add a nullable column
Add a column with a default value and a NOT NULL constraint
Rename a column
Drop a column
Change the data type of a column

To perform operations that aren't supported on compressed hypertables, first decompress the table.

Add a nullable column

To add a nullable column:

ALTER TABLE <hypertable> ADD COLUMN <column_name> <datatype>;

For example:

ALTER TABLE conditions ADD COLUMN device_id integer;

Note that adding constraints to the new column is not supported before TimescaleDB 2.6.

Add a column with a default value and a NOT NULL constraint

To add a column with a default value and a not-null constraint:

ALTER TABLE <hypertable> ADD COLUMN <column_name> <datatype>
    NOT NULL DEFAULT <default_value>;

For example:

ALTER TABLE conditions ADD COLUMN device_id integer
    NOT NULL DEFAULT 1;

Rename a column

To rename a column:

ALTER TABLE <hypertable> RENAME <column_name> TO <new_name>;

For example:

ALTER TABLE conditions RENAME device_id TO devid;

Drop a column

You can drop a column from a compressed hypertable, if the column is not an orderby or segmentby column. To drop a column:

ALTER TABLE <hypertable> DROP COLUMN <column_name>;

For example:

ALTER TABLE conditions DROP COLUMN temperature;

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