There are certain events that happen as part of a Workflow - example, person X signed off, Approvals are completed, rejections, etc that need to be part of a query on the content itself. Example: Get all specs that were approved by a person between x and y dates. Given that content model and workflow events are separate entities how are companies handling such queries? Please note that good performance is expected while performing such queries.
Re: Query for content along with Workflow properties
Most of the time (95-98%) companies are not handling this at all. Workflow data is only transient data and normally not relevant for long term / export. If workflow properties are relevant, then the workflow should contain logic that sets the relevant metadata on the document itself, so that there is a clean separation between transient data (workflow-only metadata) and relevant data (metadata on affected nodes). That way you can query for the relevant data / nodes like you query for any node - with the Alfresco search functionality, i.e. SOLR and/or transactional metadata queries.