nested transactions?

[mighdoll]

I'd like to determine the duration between a transaction and a later event in the log. You could think of it as a transaction containing a transaction... Is there a clever way to do this?

Here's a stylized example. I'd like to know the amount of time spent driving w/o seat belt. The log contains the following events. I want the duration between the pair (unfastenend,start) to end.

• seat-belt-fastened
• seat-belt-unfastened
• start-driving
• end-driving

[melting]

This is doable with lookups. There is a good blog article about how to do this from Alex Raitz:
maintain state