user1151: I wonder if they use a relational database like MySQL or do they opt for a NoSQL like CouchDB or MongoDB.
The Bitcoinica source code reveals that they used a MySQL database. 

user4023: There are multiple Bitcoin Exchanges out there, most likely they are using different DB Systems.
To be sure you should contact the particular representatives of the Exchanges.

1151: <p>I wonder if they use a relational database like MySQL or do they opt for a NoSQL like CouchDB or MongoDB.</p>

<p>The Bitcoinica source code reveals that they used a MySQL database. </p>
 4023: <p>There are multiple Bitcoin Exchanges out there, most likely they are using different DB Systems.<br>
To be sure you should contact the particular representatives of the Exchanges.</p>
