Using mgo tx is it possible to convert the pending collection to a capped collection?

[Davis Ford]

The pending collection is growing large in our dataset, and manually truncating it and compressing after is a pain.  

Can I convert the pending collections to capped with a TTL to expire the docs and remove them without an issue?

Thanks

[Ivan Mladenovic]

Yes, 

Just create TTL index and mongo will take over.

But depending on how large collection is , you may experience issues like slowdown.