# Other Features * **default** can be used to set a default value for an attribute * `create index on ()` can be used to create an index for an attribute of a relation * Large objects are stored as “large object” * **blob** (**b**inary **l**arge **ob**ject): object is a large collection of uninterpreted binary data whose interpretation is left to an application outside of the database system – video, image, etc * **clob** (**c**haracter **l**arge **ob**ject): object is a large collection of char data – book review, book content, etc * When a query returns a large object, a pointer is returned rather than the large object itself * create type can be used to create a user-defined data type: ``` create type Dollars as numeric (12,2) final ``` * create domain can be used to create user-defined domains: ``` create domain person_name char(20) not null ``` --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://vikram-bajaj.gitbook.io/cs-gy-6083-principles-of-database-systems/main-1/sql/intermediate-sql/more-sql-data-types-and-schemas/other-features.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.