Grids and large datasets

Hi Yalim,

Thanks for the response; for a few hundred or even a few thousand rows grids do seem to perform very well but getting to 10k and beyond performance does decrease considerably; I have to remind myself that when working with FS that it is not FS that is the bottleneck but the browser itself.

Thanks,

Craig.

At some point we will implement infinite scrolling. Once that's implemented I think we can even circumvent this browser limitation.

Hi Craig,

You may also consider using a paging mechanism while working with large datasets. You can easily implement such a mechanism through the paging components.

Regards,
Ibrahim

Hi Ibrahim,

Thanks for your input; I have looked at paging and certainly in some scenarios it will be a good idea but in others scenarios not so good.

Quick question about grids or rather datasources, once the data has been fetched from the DBand delivered to a grid, is it possible to iterate through the data row by row and also it is possible to read row X without performing the fetch again?

Also, once data is in a grid (whether paging or not), what kind of programmatic row navigation is available in terms of setting the current row, i.e. first row, last row, set row X?

Thanks,

Craig

Hi Craig,

Once the data has been fetched from the DBand delivered to a grid, is it possible to iterate through the data row by row?
Yes, the datasource always keeps the copy of the data delivered to a grid. Therefore, you can access these rows through the datasource APIs. If you need to loop through all rows, you can use api_datasource.getRows API. If you need to loop through the rows meeting certain criteria, you can use api_datasource.getQuery API.

It is possible to read row X without performing the fetch again?
You can access a specific row in two ways:

• Through its primary key (if a primary key column is defined in the datasource definition) using api_datasource.getRowByPK API.
• Through its row id using api_datasource.getRow API.

What kind of programmatic row navigation is available in terms of setting the current row, i.e. first row, last row, set row X?

• api_datasource.firstRow sets first row of the datasource as the current row.
• api_datasource.lastRow sets last row of the datasource as the current row.
• api_datasource.nextRow changes the current row of the datasource to the next one.
• api_datasource.previousRow changes the current row of the datasource to the previous one.
• api_datasource.setCurrentRow sets the row with the specified row id as the current row.
• api_datasource.setCurrentRowByPK sets the row with the specified primary key as the current row(a primary key column should be defined to use this API).
• api_datasource.setCurrentRowByRowNR sets the row with the specified index(rownum) as the current row.

Hope this helps,
Ibrahim