Tuesday, June 24, 2014

Everything in its Place


The Problem

“Is there an easy way to fully expand and fully collapse my pivot chart?” or its cousin,“Can I just press a button to get the pivot chart back to a default?”
These are relatively frequent questions that I never had fully satisfactory answers for.
Before we get into the tip, I used to recommend Right Click à Collapse All or Right Click à Collapse Dimension Columns to collapse the chart and Right Click à Expand All to expand columns (one-by-one).

That solution is not great because first, if you are expanding the chart all the way out, you still have to do it one column at a time.  But the biggest problem presents once you pivot a dimension horizontally.  At that point, you cannot collapse the pivoted column without first un-pivoting the column.

Solution – The Layout Bookmark

The solution to this is actually pretty neat.  It involves a special kind of bookmark – The Layout Bookmark.  Our example will simply involve a collapsed state and a fully expanded and pivoted year column state.

First create a pivot chart and manipulate the columns so that none are pivoted and all are collapsed. 

Then we simply create a document bookmark Bookmarks à Add Bookmarks as follows.


Notice that we have unchecked “Include Selections in Bookmark”.  We want to be able to invoke this bookmark without affecting the current selections.  The only thing this bookmark will change will be the “layout state” of the application.
Next, expand out all the columns and then pivot the year column horizontally. 

Create another layout bookmark.
Now we need to create a couple buttons that will simply invoke each of these layout bookmarks.  But first, we need to know the id’s.  Go to Bookmarks à More…

There you can see that the id’s for these bookmarks are BM01 and BM02.  Take note of them.
Finally, create the buttons. 
You can name the button whatever you want and then for the button action, use Bookmark à Apply Bookmark along with the id for the bookmark you with to trigger.
Here is the finished product.  Hitting the buttons will expand or collapse the chart to the desired setting.


There are some complications to be aware of when creating layout bookmarks.
·         The layout state affects the entire sheet.  When you create a layout bookmark, it is taking a snapshot of the entire sheet layout, not just the pivot chart you are concerned with.  This includes minimize/restored settings and cyclic dimensions for all objects within the sheet.

·         The layout state activates the sheet.  This means that if you put this button on a different sheet, it will activate the sheet the bookmark was created on.  This could be good or bad but is important to understand for your use-case.

·         Layout states are hidden in containers.  If your charts are in a container, the layout state for objects within the container will not be saved.


Some of the other things that might be done using layout bookmarks.
·         Default sheet state
·         Set a cyclic dimension to be shown
·         Set a grouped expression to be shown
·         Set restored or minimized objects on a sheet
·         Set which object is shown within a single style container
I would love to hear any other ideas you have for this concept or other feedback.  Happy Qliking.


Wednesday, June 18, 2014

Easy Way to Collect QVD Stats


Collecting Stats Helps Debugging and Alerts You to Problems

Most organizations will use QVD Generators to build out QVD data layers suitable for QlikView’s consumption.  There is generally no need to create any visualizations in these QVD Generators except for maybe some validation tables and some QVD statistics.  Today we will focus on an easy way to gather those statistics.  The statistics I generally gather help me answer questions regarding the output QVDs.
·         Which QVDs were written with this application?
·         How long did it take to create this QVD?
·         How many rows were written?
·         How many fields were in each table?
Obviously, being able to easily answer these questions helps us better understand and serve the BI enterprise.  It also provides a helpful tool for debugging logical errors in our QlikView scripts.
And because we actually take this statistics table and write it to QVD as well, we can use it in later loads as needed to create a data source lineage for a particular application.  Another benefit of creating this statistics QVD(s) is that I can drop all the tables that created the QVDs while still retaining the statistics.  This leaves the application light and quick to save.
Here is an example of the front end to show you what kind of data will be collected and displayed.  Of course, the stats you collect and present are really up to you, the developer.

How to set up the collection

I use blocks of code that can be basically put into any script and adjusted as needed.  We basically have four chunks of code that get deposited into our script.
1.       Set up any needed global variables and set up the statistics table structure.
2.       Set up a sub-routine that creates the stat table.
3.       Change the start time and table name each time we go to a new QVD.
4.       Call the subroutine.

Set up any needed global variables and set up the statistics table structure

First, create any variables that will need to be collected in your statistics or displayed in your front end.  For this example, we are using a variable to determine my directory, the name of my environment, the source, division and the path for my statistics QVD.  These two chunks of script should be inserted towards the beginning of the script before any loading occurs.
set vDir = 'C:\Users\Aaron\Documents\QlikView Apps\Blog Apps\Statistics Collection';
set vEnv = 'Dev';
//set vDir = 'D:\QlikView Documents\Production\Sales';

//   Set variables for qvd naming
set vDivision=  'QAP';
set vSource =   'BAAN';

LET StatisticsPath = '$(vDir)\ETL_Statistics_$(vDivision)_$(vSource).qvd';
We also will look for an existing statistics QVD and if one is not found, we will create it.
IF FileSize('$(StatisticsPath)') > 0 THEN //  The Statistics QVD already exists.
ELSE // The Statistics QVD needs to be created

    TableName, Division, Source, ReloadedDate, StartTime, EndTime, Duration, Records, Fields
    , ]

STORE Statistics INTO $(StatisticsPath)(qvd);
DROP TABLE Statistics;

Set up a sub-routine that creates the stat table

Next we create a subroutine that appends the statistics each time we load new data into a QVD.  This script records all of the needed data from whatever load has just occurred, adds it to the existing statistics records and then saves the whole thing back to QVD.  This script gets inserted just below the prior set up stuff and will be called at various times later in the script.
sub Stats

//   Call this script between qvd store and drop table commands to gather statistics for the qvd. 
     //   There must be a vStartTime and a vTable variable
     LET vEndTime = NOW();
LET vRecords = NoOfRows('$(vTable)');
LET vFields  = NoOfFields('$(vTable)');
LOAD * FROM $(StatisticsPath)(qvd)   WHERE TableName <> '$(vTable)';
JOIN (Statistics)
LOAD DISTINCT '$(vTable)' AS TableName, '$(vDivision)' AS Division, '$(vSource)' as Source, DATE(NOW()) AS ReloadedDate, '$(vStartTime)' AS StartTime, '$(vEndTime)' AS EndTime,
INTERVAL(NUM('$(vEndTime)') - NUM('$(vStartTime)'),'hh:mm:ss') AS Duration, $(vRecords) AS Records, $(vFields) as Fields
RESIDENT Statistics;
STORE Statistics INTO $(StatisticsPath)(qvd);
DROP TABLE Statistics;

end sub 

Change the start time and table name each time we go to a new QVD

So now we go about the business of loading data from our data sources and creating QVDs.  The basic idea is that we will need to establish some variables at the beginning of each load and then run the subroutine at the end of each load.  Using this approach we can collect statistics for every QVD that gets created.  Start by adding this script to the top of each data loading section.  Note the vTable variable could also be used within your load statements to name your table.
//   Append this script to the start of each qvd creation.
LET vStartTime = NOW();
SET vTable = 'ETL_Sales_Header'; 

Call the subroutine

Finally, we can call the statistics subroutine that will record our ending variables and append the QVD.  This simple code will run the routine we created in the second step.
//   call subroutine to gather statistics for the qvd.
call Stats;
Place this code after we store each data QVD.  One thing to note is that you should wait to drop the data QVD until after this subroutine runs or simply drop them all at the end of your script.


There are many ways we can simplify the data we are collecting or expand the data.  Hopefully this structure is clear and economical enough for you to adjust to your needs.  The example I provided is simply what I use to complete this task and I tweak the code depending on the situation.
As always, I hope you find this valuable.  Please let me know what you think.  And if you accomplish statistics collection differently or can improve upon this, please participate in the discussion.

Tuesday, June 3, 2014

6 Pictures Only QlikView Developers will Understand

Donald Farmer and Tommy Chong
Gurus of their respective fields
We all talk a big game with our complex table structures and fancy visualizations.  But once in a while, it is OK to let our hair down (for those of us that have some) and have some fun at our own expense.  I thought it would be a nice change of pace to offer up a few examples that might relate to our collective QlikView development experiences.  See if you can guess what QlikView concepts the pictures below represent.  I went ahead and put the caption text in white so highlighting the caption should give you the answers (might not work?).  The answers were also added at the bottom of the post.  Enjoy!
Concatenated Keys

Link Table

Synthetic Key

Section Access


Cycle Group

Here are the answers in order:
1. Concatenated Keys
2. Link Table
3. Synthetic Key
4. Section Access
5. Reload
6. Cycle Group
Thanks to  DV  over at QlikShare for the inspiration for this post.
As usual, your comments and shares are much appreciated.