SAP HANA Explained: How It Works Without Disk Storage

Modern business data is huge and needs fast access. Traditional databases use disk drives. This is slow. SAP HANA is different. It keeps data directly in memory (RAM). That’s why it’s super-fast.

If you're joining SAP HANA Online Training, one of the most technical concepts you’ll explore is this: SAP HANA works with little help from disk. It's fast because it doesn't wait to read from or write to disk during normal work.

This shift is major, especially in cities like Delhi. Here, many enterprises are switching to SAP HANA. Their goal is to get rid of slow disk-based databases. The real gain is speed and performance. Many banks, government departments, and telecom companies in Delhi now use SAP HANA for real-time reporting.

How SAP HANA Uses Memory Instead of Disk?

SAP HANA keeps data in main memory. This means data is always available. No need to fetch from disk.

When the system starts, it loads important data into RAM. This includes tables and columns that apps use daily.

When users run a query:

●  HANA processes it directly in RAM.

●  No time is wasted waiting for the disk.

●  This makes it 10x to 100x faster than old systems.

Here’s a simple flow:

●  User opens app → app sends query → HANA processes in RAM → result returned

Disk Is Still There, But Used Differently

SAP HANA still uses disk, but for safety.

Disk stores:

● Logs

● Backups

●  Savepoints (snapshots of current memory)

This makes the system fast and reliable.

So, it’s not like the disk is gone. It's just not involved during most active work.

How HANA Recovers After Crash?

Let’s say the power fails.

SAP HANA restarts.

Here’s how:

●  It reads the latest savepoint from disk.

●  Then applies log files to update memory with the latest changes.

This is faster than traditional databases where the whole system has to scan disk or run checks.

Why Column-Based Storage Helps?

HANA stores data in columns, not rows.

This helps because:

●  It allows better compression

●  RAM is used more efficiently

●  Queries run faster when they touch specific fields

Example:

●  In old DB, if you want to sum salaries, it reads whole rows

●  In HANA, it reads just the "salary" column

That’s faster and uses less CPU.

Table: RAM-Based vs Disk-Based Databases

Feature	Disk-Based DB	SAP HANA (In-Memory)
Data storage location	Disk	RAM
Speed	Slower due to disk reads	Fast due to in-RAM data
Query time	Higher latency	Very low latency
Crash recovery	Slower, checks needed	Fast using logs + savepoints
Data compression	Limited	High (columnar compression)
Concurrency (multi-users)	Affected by disk I/O	Smooth due to memory access

Local Trends: SAP HANA in Delhi

In Delhi, big data projects are everywhere—especially in public transport, health records, and telecom systems. Many of these systems now use SAP HANA. This has led to a rising need for SAP HANA experts. That’s why many learners search for SAP HANA Training Institute in Delhi.

Use Cases That Need No Disk

Here are actions in HANA that work without using the disk:

● Ad hoc reporting

● Real-time analytics dashboards

● Predictive model runs

● OLAP queries

All of these happen in memory. This is why companies love HANA. It supports real-time business.

Sum up,

SAP HANA uses in-memory computing. That’s why it doesn’t rely on disk for active work. The disk is only used for logs and safety backups. It stores data in columns, not rows. This makes it fast and compact. SAP HANA Certification focuses on HANA system sizing, memory management, and crash recovery.

These are real-world problems faced by Delhi-based SAP teams. Delhi’s demand for HANA experts is high because of real-time business applications. Understanding how HANA skips disk is critical for backend and BASIS roles.