Improve the data loading performance of table visual

Hi all.

I have started preparing a Power BI report to visualize information using table visual with drill down information option in a secondary tab in the same report. I want to increase the speed of the visualization as much as possible based on the customer filtrations.

This report has 4 DIM tables which has maximum up to 6 columns and around 10K rows in each table. Also, there's 1 fact table which contains around 1.8Milion rows with 8 columns.

This report is using direct query option to load data from oracle database. I have used SQL query to exact required columns to minimize the data modelling in the tables.  And I have made column values which need conditional formatting using "Case" function in SQL query prior to the data load. In addition to that I have disabled the auto date/time option from the global settings as well. All these were made significant improvement in report refreshing.

But even after all this, I don't see much improvement in data visualization loading. Please guide me to find the cause and solve this issue. Much appreciated community support.

Thanks.