How does a messaging product support queries?

AMPS has the capability to store real-time messages in a State of the World (SOW) database by topic -- similar to how a SQL database stores data in a table.

AMPS allows queries to the SOW database (the set of current values for each message) using content filters, similar to the way in which you query a SQL database.

The content filter uses an XPath-like Locator to identify the content of a message, similar to the use of column names in SQL database query. The SOW database in AMPS was designed with lock-free mechanisms, so that it can perform hundreds of thousands updates a second without impacting query performance.

For more information on the State of the World, see the AMPS User Guide chapter on State of the World (SOW) Topics.