Grouping records in the log_link_visit_action table by page impression

I’m trying to look at data in the log_link_visit_action table from a page impression point of view. I’m in 3.x Piwik.

It seems like the field to group records on for a single impression is the idpageview record. It also seems like because that is just a 6 character field that only utilizes 62 distinct values [a-zA-Z0-9] there is a reasonably high likelihood of collisions on that field over time. It allows for about 56.8 billion unique possible values. If I’m hitting 1 billion page views in a year I’ve got a decent chance that I’m going to have a collision, especially if I’m pulling that field over to other tables for reporting purposes and will be looking at that data over multiple years.

I’m fine with that. If we filter on other things (do some filtering by time, visitor, visit) with the idpageview, the likelihood of accidentally munging two separate page impressions into one goes way down so the error rate is negligible.

My question: Is idpageview the correct field to use to determine a group of records in the log_link_visit_action table or is there a better field?

I’m not seeing any other combination of columns in the table that would allow me to determine a unique page impression.

I would like an answer to this question as well.