The Print When Expression

The Print When Expression

The print when expression in Jasper Studio or Jasper iReport is very useful in so many requirements and it is defined as the name itself implies
i.e Print /Show a String, Column and so on Based on a condition passed.
Now here are some requirements on how/when we can implement The Print when expression.

Requiremnt: Show a particular column when a parameter is selected
Here we made a parameter Called ShowLocation with values either ‘Y’ or ‘N’/blank space
now when ‘Y’ is selected then a Location column should show and when ‘N/blank space then it doesn’t show.

2 ways i did approach this:

1. I made a 2 Table Components one with the Location Column added and the other without the Location Column added.
one on top the other.
so when my parameter calls a ‘Y’ value it picks the Table with the Location Column and vice versa.

This approach is good but can be time and performance consuming

the 2nd approach was:

2. Only one Table Component was used, Opened the Table Component and selected the Column i want to restrict/show based on the parameter passed, in my scenario or requirement it is the Location column as
shown in the image below:


now i would select the cell button

Cellin the properties Tab and then Select the
Print When Expression.

Now here in the print when expression box i would write :
$P{showlocation}.equals(“Y”) as shown above


and you are good to go for a preview.
Now Let’s have to put a N or blank space in the parameter showlocation we get the following output
and now let’s pass ‘Y’ in the showlocation parameter

So Now with this condition it will show the column when the parameter is checked in with a ‘Y’ Value.
and voila the output:


Sohail Izebhijie.

Jasper BI And Pentaho Reports Performance Optimization

In any BI solution, we create a lot of reports and dashboard. Often the developers come across the problem that the solution is not performing well, the reports are

taking a lot of time to load.
In this blog we will try to discuss the different approaches which could be used to optimize the performance.

a. Having good hardware. This ensures that the processing is not taking much time

b. Having good internet speed : This reduces latency

c. Reports with many pages: Let’s say if we are generating a report which is having 100 pages. Good part in viewing the same via BI (via web browser) (Jaspersoft and Pentaho) is that we don’t need to load all the pages before we can show it to the end user. As soon as the pages are loaded end customer can start viewing it. Hence he
can start seeing first couple of pages immediately and meanwhile the remaining pages will keep on loading and rendering to the user. But the case is not the same with other formats, if a client wants to download the report in excel/pdf/csv format, he can only download once the entire report has been loaded.

d. Caching at BI level : Jaspersoft & Pentaho, both are having caching facility. We can increase the size of the caching memory, thus this leads to improved performance.

e. Caching at database level : If we feel that some of the reports / db generally takes  a lot of time, what can be done is we can create temp tables inside db and we can put the values required for those reports in this tables. This way we can have multiple level of caching (application level and database level).

f. Optimization at query level: Using the best practices of writing sqlqueries (like avoid writing nested queries, including too many Joins etc).

g. Database indexing and controlling of users on database will also increase performance of report execution.

h. Remove unused variables / parameters / table columns with in the report.

i. Maximum Usage of built in functions which are available with in jasper and pentaho reports for calculating total / percentages / avg and for type conversions like

string to integer etc will also increase the performance of report.

j. Whenever a BI solution is developed directly hitting the transactional database, the performance is compromised. Hence its always suggested that there is separate

reporting database (or data warehouse).

k. If there are multiple input parameters (like the one present in the below snapshot), then on the submit button only the report should change.
BI Report Performance
Otherwise it will result in firing many queries to the database. Also for the report/dashboard, ideally there should not be multiple input parameters.

Navin Dasari
Helical IT Solutions