Alter a hypertable

You can alter a hypertable, for example to add a column, by using the PostgreSQL ALTER TABLE command. This works for both regular and distributed hypertables.

You can add a column to a hypertable using the ALTER TABLE command. In this example, the hypertable is named conditions and the new column is named humidity:

ALTER TABLE conditions
  ADD COLUMN humidity DOUBLE PRECISION NULL;

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If the column you are adding has the default value set to NULL, or has no default value, then adding a column is relatively fast. If you set the default to a non-null value, it takes longer, because it needs to fill in this value for all existing rows of all existing chunks.

Important

You cannot add a column with constraints or defaults to a hypertable that has compression enabled. To add the column, you need to decompress the data in the hypertable, add the column, and then compress the data.

You can change the name of a hypertable using the ALTER TABLE command. In this example, the hypertable is called conditions, and is being changed to the new name, weather:

ALTER TABLE conditions
  RENAME TO weather;

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