Perf: Course dashboard performance issues

[bmtcril]

Tested with the 300M row dataset on ClickHouse Cloud I've found the following issues:

OOM Errors:

• Problem Results
• Problem Interactions
• Watched Video Segments
• Partial and full views per video

Slow Queries (> 3 seconds):

• Problems attempted per section/subsection (43 rows, 5 seconds)
• Video views per section/subsection (24 rows, 4 seconds)
• Page views per section/subsection (37 rows, 3 seconds)

[SoryRawyer]

I have been trying to make changes to int_problem_results in dbt, but so far the best results have been when I could filter the subqueries individually. This suggests to me that we should move int_problem_results into Superset and rely on templating to make sure queries make proper use of indexes.

I will look into a similar approach for the watched video segments query.

[Ian2012]

@SoryRawyer I think I can move this dataset to a MV with MergeEngine: https://github.com/openedx/aspects-dbt/blob/b16a7957de4506e22768cb4a610798113c9868a2/models/problems/int_problem_results.sql#L4

Would that also be a suitable solution? cc @bmtcril

[bmtcril]

Fixes for everything but problem interactions and problem results are here #808

[Ian2012]

fixes for problem interactions - problem results are here: #825

[bmtcril]

I believe these issues are all fixed now!