john-bodley opened a new pull request, #25995: URL: https://github.com/apache/superset/pull/25995
<!--- Please write the PR title following the conventions at https://www.conventionalcommits.org/en/v1.0.0/ Example: fix(dashboard): load charts correctly --> ### SUMMARY At Airbnb (as mentioned previously) we have an uber wide dataset (circa thousands of columns) which is can be somewhat problematic for certain workflows. One such workflow is fetching sample data—which is used in explore and drill-to-detail. The existing logic constructs and executes a query for fetching both the sample data and `COUNT(*)` where the former is rather complex—relying on a very expensive SQLAlchemy query to fetch all the columns—before processing the results. This PR introduces an optimization which first constructs and executes the `COUNT(*)` query (which is both cheap to construct and execute) and only proceeds to the sample data if the first query succeeds. Given that (in out formulation) the `COUNT(*)` aggregate is not supported the endpoint returns in a few seconds as opposed from a few minutes. ### BEFORE/AFTER SCREENSHOTS OR ANIMATED GIF #### BEFORE <img width="873" alt="Screenshot 2023-11-15 at 2 16 57 PM" src="https://github.com/apache/superset/assets/4567245/0ab6e286-c065-4d91-a0af-7d21240dafb7";> #### AFTER <img width="873" alt="Screenshot 2023-11-15 at 2 17 15 PM" src="https://github.com/apache/superset/assets/4567245/4fe44f19-3e2c-433a-bc95-1abcd9dc36d1";> ### TESTING INSTRUCTIONS Existing unit tests. ### ADDITIONAL INFORMATION <!--- Check any relevant boxes with "x" --> <!--- HINT: Include "Fixes #nnn" if you are fixing an existing issue --> - [ ] Has associated issue: - [ ] Required feature flags: - [ ] Changes UI - [ ] Includes DB Migration (follow approval process in [SIP-59](https://github.com/apache/superset/issues/13351)) - [ ] Migration is atomic, supports rollback & is backwards-compatible - [ ] Confirm DB migration upgrade and downgrade tested - [ ] Runtime estimates and downtime expectations provided - [ ] Introduces new feature or API - [ ] Removes existing feature or API -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
