pedro-r-marques opened a new pull request, #27899: URL: https://github.com/apache/superset/pull/27899
### SUMMARY As per issue #27897, SqlAlchemy recommends that """ The typical usage of [create_engine()](https://docs.sqlalchemy.org/en/20/core/engines.html#sqlalchemy.create_engine) is once per particular database URL, held globally for the lifetime of a single application process. A single [Engine](https://docs.sqlalchemy.org/en/20/core/connections.html#sqlalchemy.engine.Engine) manages many individual [DBAPI](https://docs.sqlalchemy.org/en/20/glossary.html#term-DBAPI) connections on behalf of the process and is intended to be called upon in a concurrent fashion. The [Engine](https://docs.sqlalchemy.org/en/20/core/connections.html#sqlalchemy.engine.Engine) is not synonymous to the DBAPI connect() function, which represents just one connection resource - the [Engine](https://docs.sqlalchemy.org/en/20/core/connections.html#sqlalchemy.engine.Engine) is most efficient when created just once at the module level of an application, not per-object or per-function call. """ The superset.models.core::Database class is currently allocating Engine objects whenever a Database object is instantiated which happens twice(?) per 'api/v1/chart/data' API access. This is not the intended usage of the SQL Alchemy API and causes mechanisms such as connection pooling not to work correctly. Connection pooling is an important feature in order to control access to databases. For instance when using 'duckdb', it is recommended that one uses a small number of concurrent requests (or a single concurrent request) and instead take advantage of the inherent parallelism in the database engine. Other engines will have other ideal settings. ### TESTING INSTRUCTIONS <!--- Required! What steps can be taken to manually verify the changes? --> Configure a connection pool using the `DB_CONNECTION_MUTATOR` hook. ### 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: notifications-unsubscr...@superset.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org --------------------------------------------------------------------- To unsubscribe, e-mail: notifications-unsubscr...@superset.apache.org For additional commands, e-mail: notifications-h...@superset.apache.org
