Deleting Custom Column Families
You can delete a column family in a JSON table either with the
command maprcli table cf delete
or with the
Admin.deleteFamily()
Java method.
Permissions Required
The readAce
and writeAce
permissions on the volumes where
the JSON tables are located. For information about how to set
permissions on volumes, see Setting/Modifying Whole Volume ACEs.
Example of using the Admin.deleteFamily()
method
public void deleteColumnFamily(String tablePath, String familyName) throws DBException {
try (Admin admin = MapRDB.newAdmin()) {
if (admin.tableExists(tablePath)) {
admin.deleteFamily(tablePath, familyName);
}
}
}
Parameter | Description |
---|---|
tablePath |
The path of the table in the MapR file system. See Table Paths. |
familyName |
The name of the column family to delete. You cannot delete the default column family. If familyName is equal to "default", the API returns an exception. |
The data that is in the specified column family is deleted. If the column family is
followed by one or more column families in a hierarchy, the other column families in the
hierarchy are unaffected and still accessible. For example, if column family
CF1
at path a.c
is followed by column family
CF2
at path a.c.f
, CF2
remains
accessible and only the data in CF1
is deleted.
Before deleting the column family CF1 at a.c
|
After deleting the column family CF1 at a.c
|
---|---|
|
|