rasql insert within an MDD object

[Dimitar Misev]

In the way partial updates are supported we should support insert into an existing MDD object. This would allow to insert time slices in a time-series for example, after some data has already been ingested.

Example

insert into 3Dcube[5,*:*,*:*]
values VALUES

This would insert the VALUES (a 2D object) into the existing 3D objects in 3Dcube at slice t=5. The existing slices at t≥5 will be moved to t+1, i.e. slice 5 becomes 6, etc.

Implementation: this could be implemented efficiently without moving any data but just shifting some OIDs in the index.