title: How well does a unique hash index perform in comparison to the record ID?
body: <p>Following CQRS practices, I will need to supply a custom generated ID (like a <code>UUID</code>) in any <code>create</code> command. This means when using <a href="http://orientdb.com" rel="nofollow noreferrer">OrientDB</a> as storage, I won't be able to use its generated <code>RIDs</code>, but rather perform lookups on a manual index using the <code>UUIDs</code>.</p>
  
  <p>Now in the <a href="http://orientdb.com" rel="nofollow noreferrer">OrientDB</a> docs it states that the performance of fetching records using the <code>RID</code> is independent of the database size <code>O(1)</code>, presumably because it already describes the physical location of the record. Is that also the case when using a <code>UNIQUE_HASH_INDEX</code>?</p>
  
  <p>Is it worth bending CQRS practices to request a <code>RID</code> from the database when assembling the <code>create</code> command, or is the performance difference negligible?</p>