Deleting Objects

The delete command follows a predictable pattern and looks like this:

DELETE /types/TYPE/buckets/BUCKET/keys/KEY

The normal HTTP response codes for DELETE operations are 204 No Content and 404 Not Found. 404 responses are normal, in the sense that DELETE operations are idempotent and not finding the resource has the same effect as deleting it.

Let’s try to delete the genius key from the oscar_wilde bucket (which bears the type quotes):

Location geniusQuote = new Location(new Namespace("quotes", "oscar_wilde"), "genius");
DeleteValue delete = new DeleteValue.Builder(geniusQuote).build();
client.execute(delete);

bucket = client.bucket_type('quotes').bucket('oscar_wilde')
bucket.delete('genius')

(new /Basho/Riak/Command/Builder/DeleteObject($riak))
  ->buildBucket('oscar_wilde', 'quotes')
  ->build()
  ->execute();

bucket = client.bucket_type('quotes').bucket('oscar_wilde')
bucket.delete('genius')

var id = new RiakObjectId("users", "random_user_keys", null);
var obj = new RiakObject(id, @"{'user':'data'}",
    RiakConstants.ContentTypes.ApplicationJson);
var rslt = client.Put(obj);
string key = rslt.Value.Key;
id = new RiakObjectId("users", "random_user_keys", key);
var del_rslt = client.Delete(id);

// continuing from above example
options = {
    bucketType: 'users', bucket: 'random_user_keys',
    key: generatedKey
};
client.deleteValue(options, function (err, rslt) {
    if (err) {
        throw new Error(err);
    }
});

riakc_pb_socket:delete(Pid, {<<"quotes">>, <<"oscar_wilde">>}, <<"genius">>)

// Continuing from above example
cmd, err = riak.NewDeleteValueCommandBuilder().
    WithBucketType("users").
    WithBucket("random_user_keys").
    WithKey(rsp.GeneratedKey).
    Build()

if err != nil {
    fmt.Println(err.Error())
    return
}

if err := cluster.Execute(cmd); err != nil {
    fmt.Println(err.Error())
    return
}

curl -XDELETE http://localhost:8098/types/quotes/buckets/oscar_wilde/keys/genius

Client Library Examples

If you are updating an object that has been deleted—or if an update might target a deleted object—we recommend that you first fetch the causal context of the object prior to updating. This can be done by setting the deletedvclock parameter to true as part of the fetch operation. This can also be done with the official Riak clients for Ruby, Java, and Erlang, as in the example below:

object.delete
deleted_object = bucket.get('bucket', 'key', deletedvclock: true)
deleted_object.vclock

# It is not currently possible to fetch the causal context for a deleted
# key in the Python client.

Location loc = new Location("<bucket>")
    .setBucketType("<bucket_type>")
    .setKey("<key>");
FetchValue fetch = new FetchValue.Builder(loc)
    .withOption(Option.DELETED_VCLOCK, true)
    .build();
FetchValue.Response response = client.execute(fetch);
System.out.println(response.getVclock().asString());

{ok, Obj} = riakc_pb_socket:get(Pid,
                              {<<"bucket_type">>, <<"bucket">>},
                              <<"key">>,
                              [{deleted_vclock}]).

%% In the Erlang client, the vector clock is accessible using the Obj
%% object obtained above.

$response = (new /Basho/Riak/Command/Builder/FetchObject($riak))
  ->buildLocation('deleted_key', 'in_some_bucket', 'of_a_certain_type')
  ->build()
  ->execute();

echo $response->getVclock(); // a85hYGBgzGDKBVI8m9WOeb835ZRhYCg1zGBKZM5jZdhnceAcXxYA