ADF : af:table or adf form or adf page taking too much time to load

During the development sometimes we come across this problem. In our case we had a table on a page and it was taking too much time to load, even though there were only one row in the database table but then also it was taking more than enough time to load. After the analysing the problem finally we were able to solved the problem.

The main problem was with the List of Values with SingleSelection which was inserted in the table. In a column we had to show the name in place of the id, so the developer created a List of Values in the viewObject and put it in the table on page. At first it was working fine but later as the number of rows grown in the List of values the list started taking time to load.

The main cause was the number of rows in the list of values. Single selection list of values matches the id with the value and shows values, so inorder to map it needs all the rows, so whenever the table was being load the ListOfValues started to fetch all the rows, and as the number of rows was too much so abviously it was taking too much time. So, we had to replace the list of values but we also had to show the name in place of id. 

So there are many ways to do that : 

1. We can include the name that we have to display in the query of the table itself, because of which we can simply display it in a column.

2. Otherwise we have to use a viewobject with query that returns a less number of rows and better if it returns one row with the id and DisplayName. 

Suppose we have to show Department Name in place of department id in Employees Table. The query will be something like this : SELECT DEPARTMENT_NAME FROM DEPARTMENTS WHERE DEPARTMENT_ID = :DeptIdBind

And then we need to show the display name so we created a transient attribute.

Then in the getter of the transient attribute, get the viewObject and pass the bindVariables and execute the query. The query will return a row and then we can fetch the name from the view object and show it by returning it.

There is a disadvantage of using this method, as the query is executed for all the rows fetched in the table. But page load problem will be solved. 

This may depend on the use case.  For us both worked well.

I will suggest never to use SingleSelection List of Values that contains large number of rows in the page. Not even on the adf form. Because due to that it will take too much time to load.

Thanks for reading. If you have any question, Please feel free to ask.