Managing Column Families
JSON tables store data in column families, which are collections of fields that are stored together on disk.
Each table has a default column family, which is default storage for all fields in the documents of a table. You can create additional column families to store data for a collection of fields in a separate location on disk. Queries that operate only on data that is stored in a column family are more efficient and better performing than queries on the same data when that data is stored with other data in a table. You can also cache values from a column family in memory.
Applications do not need to be aware of the existence of column families. They perform CRUD
operations by using the paths of fields in a document. For example, to update any of the
fields below a.c
, an application does not need to be aware that the field
is in the column family at the path a.c
. The application simply moves
through the document along the path to the field.
For more information, see Column Families in JSON Tables.