After updating the value in the database, it should reflect in the screen

I think your best bet is to use the a!refreshVariable() function inside a!localVariables(): 

https://docs.appian.com/suite/help/latest/fnc_evaluation_a_refreshvariable.html

This function can refresh the interface on an interval to show changes after a database operation. There are also a few interface patterns that describe how to do this: https://docs.appian.com/suite/help/latest/recipe-refresh-until-asynchronous-action-completes.html

Hi,

I did try using refreshVariable, but it is taking about 30 seconds to change. Is there any other way which we can use so that the changes reflect immediately after the database save? 

What method of database save are you referring to?  Is it a process model with a Write to Data Store node, or an on-form database save, or something else?

It is a process model with a Write to Data Store Node.

Is the database update initiated by the user on the form or is it a completely asynchronous activity? If it's asynchronous from the interface, then using the refreshVariable is probably your only option. However, if the database update is triggered by the user on the interface, you might be able to use the a!writeToDataStoreEntity() function instead of a process model. This function lets you receive a response from the database with the data written after it completes using the onSuccess parameter. See this page for more information: https://docs.appian.com/suite/help/latest/recipe-use-the-write-to-data-store-entity-smart-service-function-on-an-interface.html

is this process 100% asynchronous, i.e. the user never leaves the record?
OR
does the user leave the record when this process is started via a related action that navigates them to a task form that they would submit.

I know it's very specific, but if it's the latter, you can try activity chaining from the first flow of the process to at least the flow that follows the write to data store entity.  This would ensure that the user isn't navigated back to the record until after the write is completed.

is this process 100% asynchronous, i.e. the user never leaves the record?
OR
does the user leave the record when this process is started via a related action that navigates them to a task form that they would submit.

I know it's very specific, but if it's the latter, you can try activity chaining from the first flow of the process to at least the flow that follows the write to data store entity.  This would ensure that the user isn't navigated back to the record until after the write is completed.