In this chapter you will come to know how SAP HANA collaborates transactional and analytical data into one to allow  seamless activities on the database. The database of SAP HANA is developed in C++ and consists of more than one servers. Let us learn about the servers :

• Index Server – It is the prime server of SAP HANA that contains actual data and processing engines. This server processes the SQL and MDX statements when authentication and transactions are required.

• Persistence Layer – This layer maintains atomicity and durability of transactions. It is accountable to make sure that the database is able to be restored to the recent state and transactions are properly executed or not left in the middle.

• Preprocessor Server – This server analyzes text data and extracts information with the help of Preprocessors.

• Name Server – This server maintains the detailed information about the system topology. It keeps the updates about all the components and their location.

• Statistic Server – This server maintains log of other servers and their details such as status, performance, allocation/consumption of resources, etc. This data is used to keep track of the clients and alert monitors.

• Session and Transaction Manager – This server monitors the database transactions and their execution. When a transaction is committed or rolled back, Transaction manager informs the storage engines to take necessary measures.

• XS Engine – This server facilitates communication between external applications and SAP HANA system via HTTP in a web browser.