How SAP HANA Stores Data?

Knowing the SAP HANA data storage is necessary as data storage in it varies from the old database management systems in numerous ways. Primarily, you should know the differences as well as all the components of SAP HANA. Here are some types of data storage in SAP HANA.

OLAP and OLTP Data Storage

As compared to the traditional database, storing the data in the SAP HANA is different. The first point is SAP HANA is RDBMS (Relational Database Management System) in which data storage is done completely in memory despite of the relational data, and stored completely on hardware.

Earlier, storing the data in memory was a revolutionary concept, which had the critics making statements like "Data for warehouse structure or application will never fit in the memory." It was an unconventional idea which took time to catch on. Most of the renowned vendors have in-memory services as well as pushing stance and in-memory platform for SAP. The data that is loaded in the SAP HANA can be used by the external apps performing at blazing fast speed. In simple words, response time is exceedingly fast.

OLTP Storage Methods

Relational database or OLTP stores the data normally at the core. Basically, the data is standardized to minimize the redundant data as well as patterns of data storage in order to optimize the premium disk space; hence, writing the data on disk is very fast.

Retrieving the data through OLTP system needs various combinations of different yet related tables. As far as processing in the database designs is considered, it is an expensive technique. Mostly, reporting in the systems is an afterthought. In order to solve these issues, techniques like OLAP were invented.

OLAP Storage Methods

The data storage methods of OLAP were developed in order to combat the slowness of data access to and from the disk as well as due to the data stored in relational databases. OLAP data storage technology physically stores data in various ways since traversing the relational database on the disk is not the fastest solution for retrieving or reading the data. The star schema, or OLAP structure, permits flexibility of data drilling in case complex hierarchies occur in the data base, or you are utilizing date dimension in order to search as well as sort. OLAP also offers calculations or data-based aggregations.

Columnar Data Storage

One of the most relevant data storage technologies to SAP HANA is columnar data storage. The columnar data bases work out the issue of disk slowness by changing the method of storing the data on disk. It is essential for you to have common understanding of the columnar architectures. The columnar databases have been around since long ago, and this concept was not founded with the SAP HANA. Instead, it was design methodology, integrated in the SAP HANA for several data storage characteristics and unique features brought to data storage by the columnar data storage. Moreover, columnar databases use tables in order to store the data, whereas the data placed on disk varies from usual row-store tables. The data values are collected and then stored in the columns irrespective of rows in SAP HANA

The main components of SAP HANA architecture are as follows:

1) Client libraries: These are imported into the applications and help connect the latter to data engines.
2) SAP HANA Index Server: This is the main server that stores and processes data.

The components of this server are discussed below:

Data engines: This component comprises multiple engines depending on your configuration.
Session and Transaction Manager: This component creates and validates sessions for users. When a session has been created, the manager keeps a track of the connection status and grants user permissions depending on their profiles.
Persistence Layer: This layer is responsible for maintaining transaction logs and ensuring the durability of transactions.
Repository: As the name implies, this part stores the output from the data engines.
SQL Processor: This performs the function of processing the incoming SQL queries.

3) Name Server: This server determines which components of the SAP HANA are active and where data has been stored.
4) Statistical server: Statistical server is responsible for assessing the health of SAP HANA components. It keeps a track of the overall system performance and also monitors the allocation of resources.
5) Preprocessor server: This is used by the index server to extract and analyze text data as per the search made by users.
6) XS Engine: This is an optional component of HANA that can be used to connect HTML or Java-based applications with HANA using HTTP or HTTPS.
7) Update Components:

SAP HANA architecture also includes several update components such as:

Software Update Manager
SAP HANA Studio Repository
SAP Host Agents