OQL

On the surface, OQL seems remarkably similar to SQL, and thus supposedly just as powerful and easy to use.

The syntax for OQL is similar to that of SQL but it lets you query the object model rather than directly querying the database.

Internally, Castor's OQL implementation translates the OQL query into the appropriate SQL for the database.

Further details on the Castor OQL implementation are beyond the scope of this article.

Castor provides an implementation of a subset of the ODMG 3. 0 specification for the Object Query Language (OQL).

OQL queries can also invoke methods on the objects themselves, use regular expressions as part of the query, and use built-in query tools.

Other less familiar query languages include Object Query Language (OQL) and XQuery.

Combining jhat with OQL is a powerful way to do a targeted investigation of a misbehaving heap.

Fortunately, jhat supports an OQL syntax for doing that analysis.

Ramnarayan added that GFMon also provides ad-hoc querying facilities via OQL.

The drawback of OQL is that it wants to return . . . what?

Below are some simple examples of OQL queries.

For example, running an OQL query for all Strings with more than 100 characters would look like this