Hey everyone 👋 Can a star-tree index be used with a multi-dimensional column specified in the split order?

you mean multi-valued column?

Yes, sorry

No, start-tree index cannot support multi-valued column.. the behavior is undefined

When you say cannot support, do you mean currently, or ever?

ever

Suppose you have a table which has these following dimensions

entityId: String
groupIds: List of strings
status: String

And a query looking like this

SELECT COUNT(*) FROM table WHERE entityId = 'ID' AND groupIds CONTAINS 'group_1' AND status = 'ONLINE'

If there are 2 billion rows here, this could be a very intense query. If the star tree index could pre-aggregate on each value in groupId, you could potentially make this lookup much more performant. This is pretty much a problem we have today. A group can contain multiple entities, and an entity can be in multiple groups. There is a many to many relationship, meaning this is a dynamic constraint of our queries. Some queries will ignore group, (that would be the star node), while some need to access the aggregation on a group basis.

if there is only one attribute in the query, we can solve it but its hard to solve groupIds contains group_1, group_2

Right that makes perfect sense. In my case the query would only ever contain one groupId, so I guess in theory that could work then

yeah, thats a possibility to support it with that constraint.. can you please file a github issue with the example you have

Yes 👍 I'll do that