In 2018, we have created 2 custom records, waves (header) and waves lines (lines). Waves has an id and waves lines as the waveid, which is the id of the waves. It's been working fine but now, we have "tons" of records. So when we look at the waves lines for a waves, performance is affected. Is there's a way to add an index to a custom record ? In our case I would like to add an index on waves_lines.waveid ?

Just curious.. When you say tons of records, how many records you're talking about approx.? When you say performance is affected, is it to specifically run saved searches on these custom records or even to create/edit these records?