Deleting Column Families

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 Whole Volume ACEs.

Behavior

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.

{
 "a" : {
         "b" : "value_b",
         "c" : {
                 "d" : "value_d",
                 "e" : "value_e",
                 "f" : {
                         "g" : "value_g",
                         "h" : "value_h"
                       }
                }
       }
}

{
 "a" : {
         "b" : "value_b",
         "c" : {
                 "d" : "",
                 "e" : "",
                 "f" : {
                         "g" : "value_g",
                         "h" : "value_h"
                       }
                }
       }
}

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);
      }
    }
}