DocAnalyzer is a tool to help tune the performance — response time and resource requirements — of a Qlikview QVW. DocAnalyzer can identify unused Fields and pinpoint slow charts.
How do you use DocAnalyzer? After identifying the QVW to be analyzed. press the “Extract Metadata” button to begin the analysis process. When the extract is complete, you’ll receive a popup message. The extract can take anywhere from a few seconds to several minutes for documents with many thousands of objects.
When the extract is complete, you must run a Reload of Document Analyzer. A button is provided for this or you can do Ctrl-R.
What can you discover in the analysis? Here are a few items.
– The Fields sheet will give you an overview of what fields are used and unused and where they are used — Dimensions, Expressions, Variables, etc.
A Listbox is provided with suggested DROP FIELD script statements for the unused fields.
Select $date and $timestamp in “Field Tag” listbox. Examine the “Symbols Size” column in the Field References chart. Dates and Timestamps can be stored in 8 bytes, but frequently get converted to longer string representations during loading. The impact is only significant if there are a large amount of Distinct Values.
– The Memory sheet provides an overview and detail of RAM requirements and estimates how much memory could be saved by dropping unused fields.
– The Object sheet lists all Objects along with their Calc Time and RAM Size.
Selecting a single object will enable a “Goto Object” that open the target document and Activate that object so you can examine it’s properties.
There are many other areas you can examine such as the use and performance of Calculated Dimensions, Groups, Expression contents and what properties use those expressions.
Document Analyzer is one of the Tools that Oleg Troyansky will present in his “Performance Tuning” session at the upcoming Masters Summit for Qlikview in Amsterdam Oct 1. I hope you can join us there for more performance tips and a chance to learn advanced Qlikview development skills.