20K records is generally not a large volume for Qlik Sense. If the dashboard is taking a long time to open, I would first check the data model, number of visualizations on the sheet, and complex expressions/Set Analysis.
Also check for synthetic keys, unnecessary fields, Section Access, and Engine CPU/RAM utilization while opening the app. Reducing the number of objects and optimizing heavy expressions can significantly improve sheet opening time.
Qlik’s official performance guidance also recommends reviewing the data model, visualizations, and expressions when troubleshooting app performance.
Important: With only ~20K records, I would first investigate chart expressions, number of objects, data model design, and Qlik Compose/SQL processing rather than the data volume itself.
Is it the first open or subsequent opens as well? Look into the details of the opening steps to get an idea where the problem may be. You can get opening step detail with timings from the commercial QSDA Pro or free Qlik Explorer for Developers.
