Cache Behavior of Jedox Web Spreadsheets

When a Jedox Web Spreadsheet loads in the browser, or when a user scrolls through a spreadsheet, Jedox Web is aware of the viewport (i.e. the area that is visible in the user's browser window) and fetches data only for that viewport, plus a buffer space. This reduces the amount of data that needs to be transferred from the Jedox Web server to the browser. On the other hand, this also implies that when a user navigates/scrolls through the spreadsheet, at some point additional data needs to be fetched. This can cause a very short pause in the scrolling mechanism.

You can increase the amount of data that is fetched both during the initial load of a spreadsheet and when scrolling through the sheet. To do so, go to Administration > Settings and look under the heading Spreadsheet. The following two keys control the cache behavior:

Preload coefficient Controls the amount of data fetched during the initial load of spreadsheet.
Read-ahead coefficient Controls the amount of data that appears when scrolling.

The values are factors for the buffer of data fetched in relation to the viewport (the visible area of your screen). When you view a spreadsheet on your monitor, Jedox fetches the data for the portion of the spreadsheet that you can see plus a factor of X, as defined in the cache settings. By default, the cache is set to 2, which is roughly two screens of a spreadsheet.

Depending on the layout of the spreadsheet (specifically, the height of rows and thus their amount in the visible area of web spreadsheets), it may be necessary for Jedox Web to fetch data when scrolling is started in some cases, regardless of the aforementioned setting values.

Note: the default values for both settings appear as 0 in the user interface, but in practice, the default values are 2. This anomaly is due to legacy constraints in the software.

Increasing the cache behavior settings may prevent data fetching while scrolling in a spreadsheet, but it also increases the time required for the initial load of the sheet, as more data has to be fetched upfront.

See also

Spreadsheet Calculation in Jedox Web

Updated January 29, 2024