Can Velox LazyVectors Do Async IO ?

[adongfan]

Hi Guys,

I noticed the introduction of LazyVector in Velox, along with its related code implementation. The design concept of LazyVector is excellent; it employs lazy loading to only fetch the necessary rows of data as needed during expression evaluation, thereby minimizing I/O as much as possible.

However, I find it somewhat odd that, the loading process for LazyVector is synchronous, whereas data loading by the connector is generally performed asynchronously from storage. Moreover, since expression execution occurs on threads rather than coroutines, this synchronous calling can continuously occupy thread resources when encountering I/O wait.

Is this current approach viable? Or are there any other techniques or considerations to take into account when using it?