Hana is a Database or Memory and why BW on Hana?

[Former Member]

Dear Experts,

I have read few documents regarding Hana and I am confused?

Following is my understanding. Correct me if I am wrong in my understanding?

1. I believe Hana is a database(a different kind of data base with Software and hardware) which stores the data and is very fast.

This Hana Database comprises of both Drive and Ram. Hana's Drive is for storing the Data permanently and Hana's Ram is where the full data from Drive is transferred to Ram and in-memory calculation happens which is very fast.

2. I read that we can have 2 options,a Standalone Hana which reads data from SAP ERP and BW on Hana. Why do we need to have BW on Hana, we can just have Hana itself right, because even without BW its faster?

Please correct me if I am wrong.

Regards

Sam

[Former Member]

A) hana is a database, which combines memory and technology.

A common hana server has at leaste 128gb ram. why? because the tables (or columns of that tables) are loaded in memory and are consumed from there. Hana uses compresion (1:11 ratio) and use columnar tables, because it speeds up the data reading from the database.

Hana have 3 parts of storage:

1) memory (explained above)

2) data: the disk where data is recorded

3) log: the disk where the last transactions are logged and it provides with recovery fails

B) you can have diferents scenearios (I will explain some of them):

BW on hana: it speeds up the data access due to hana technology

suite on hana: ERP and BW on hana

Hana has your DW database: you can use hana like a common database and benefits your organization with the speed of hana.

hope it helps.

this image can show you the diferents scenarios

http://esj.com/articles/2014/07/25/~/media/ECG/VirtualizationReview/Images/2014/07/0714vrm_hana.png