The number of events returned is less than expected when applying both epoch value filtering and epoch time filtering

Tech Note: TN0836
Product: OpenEx, OpenExplorer, OpenDeveloper
Version: 2.6, 2.8
Date Added: 2008-08-06


This issue is known to occur in OpenExplorer and OpenDeveloper when using epoch value filters as well as an epoch time filter but might occur in other OpenEx clients that access and filter data. The overall time range of events could be limited erroneously, resulting in events returned for only a fraction of the total desired time range.

For example, you have a block of data that includes spike snippets and epochs storing stimulus parameters. You apply value filters to the epoch stimulus events while also applying an epoch time filter to the snippet data before reading back the spike events. Your data is known to have good epoch conditions spanning timestamps from 0 to N seconds and spike events timestamped in the range from 0 to N seconds. After applying both epoch value and time filters, the number of events returned reduces drastically and the query appears to miss events that should be returned, with maximum timestamps of the spike events being much less than N seconds.


Upgrade to OpenEx version 2.10 or later.