Learn about how SAP HANA and SAP BusinessObjects visualization panel data is shared.
The difference is not too much — it is almost always less than 1 percent, which leads to suspicion that this could be a possible rounding issue.
Here is this is the reason for the data mis-match: Explorer sends out two SQL queries internally to the database: One for the facets part and one for the visualizations part. These queries are sent sequentially, and there is a time lag between when the queries are fired.
From the time the facets query is fired to the time when the visualization query is fired (the time is approximately 15 seconds), additional data is replicated into the HANA database, and the query for the visualizations fetches data from the facets query plus additional replicated data.
This is yet another piece of evidence that HANA performs replication and query performance at high speed. Imagine, new data is loaded, available for reporting, and picked up by the Explorer query, all in 15 seconds. This means the second query fetched data from the system which is less than 15 seconds old.
Does this mean HANA is too fast for Explorer? This particular situation was unique because of the rate of data replication into the system. There was no point in time in which data was not being replicated.
As you can imagine, this is not the case always. Explorer is designed to explore on historic data, which means even if there are a few records added in the time lag between queries, it would not affect the user’s decision. A refresh on Explorer synchronizes data, and both facets and visualizations show the latest data. The facets are used mostly for filtering and drilling down, and the “actual” data is viewed via the visualizations. And if the program was altered to refresh the different parts all at once, it would affect performance.
These are still early days for in-memory technology. With HANA and other products, SAP is on the right track in removing IT as a bottleneck in providing management information to business.
Rakesh Kalyankar
Rakesh Kalyankar is an SAP NetWeaver BW- and HANA-certified lead and architect, working with SAP Global Delivery in Bangalore, India. He speaks regularly at events, such as SAP TechEd and BIIG. He is also an SAP trainer and writes frequently about SAP NetWeaver BW and SAP HANA topics. Prior to his starting his consulting work, he was part of the SAP NetWeaver BW research and development team at SAP Labs, and he has worked on the development life cycles of SAP NetWeaver BW releases, including versions 7.30 and 7.03.
If you have comments about this article or would like to submit an article idea, please contact the BI editor.
You may contact the author at rakesh.kalyankar@gmail.com.
If you have comments about this article or publication, or would like to submit an article idea, please contact the editor.
Premium
