In Secondary Indexes of DynamoDB, which of the following is NOTcorrect?

1. Global secondary index – An index with a partition key and sortkey that can be different from those on the table.
2. DynamoDB requires that you use indexes, and they give yourapplications more flexibility when querying your data
3. A secondary index lets you query the data in the table using analternate key, in addition to queries against the primarykey
4. Local secondary index – An index that has the same partitionkey as the table, but a different sort key.