Ohad Levy wrote:

once new facts comes in, old facts (e.g. facts that dont exists in the new facts set) gets deleted automatically.

If I stop collecting a custom fact or rename the custom fact, does that fact automatically get deleted? The main reason I came up with the solution is that we were collecting some poorly built custom facts that resulted in ~174k fact_name entries and ~12 million fact values in the database. The sheer volume of the facts broke the javascript on the drop down box for "Trendable" when creating a new trend counter.

We have since stopped collecting the facts that were adding the extra entries that we weren't really using. I have come up with a coded solution similar to reports:expire that allows me to delete the fact name and values for the fact names that we are not longer collecting which allowed me to get the total values down far enough to use the trendable drop down box to create a new trend.