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SAP BW/4HANA › Overview & Simplification
Getting Started

Overview & Simplification

SAP BW/4HANA is SAP's next-generation data warehouse, built entirely and exclusively for the SAP HANA database. It represents a massive simplification over legacy BW systems.

The "Simplification" Philosophy

In traditional SAP BW (BW 7.x), modelers had to choose from over a dozen object types (InfoCubes, standard DSOs, Write-Optimized DSOs, MultiProviders, InfoSets, PSAs). In BW/4HANA, the object model has been drastically reduced and consolidated.

Legacy BW ObjectReplaced by in BW/4HANA
InfoCubeAdvanced DSO (aDSO)
DataStore Object (Classic, Write-Optimized, Direct Update)Advanced DSO (aDSO)
PSA (Persistent Staging Area)Advanced DSO (aDSO) or obsolete via ODP
MultiProvider & InfoSetCompositeProvider (HCPR)
VirtualProvider / TransientProviderOpen ODS View
Modeling Interface: SAP GUI (RSA1) is largely retired for modeling. All BW/4HANA data modeling is performed in Eclipse via the SAP BW Modeling Tools (BWMT).

Key Benefits

  • HANA Pushdown: Logic is pushed down to the HANA database level (via AMDP) rather than running in the ABAP application server, resulting in exponential performance gains.
  • Agile Modeling: Virtualization (Open ODS views) allows connecting to data without physically copying it.
  • Modern UI: Administration is handled in the web-based SAP BW/4HANA Cockpit (Fiori).
Getting Started

LSA++ Architecture

Layered Scalable Architecture (LSA++) is the best-practice framework for designing the data warehouse layers in BW/4HANA.

Evolution from LSA to LSA++

Traditional LSA (for non-HANA DBs) required heavy physical data duplication across multiple layers (Staging > Integration > Data Mart) to achieve acceptable query performance. LSA++ leverages HANA's in-memory speed to eliminate unnecessary physical layers and rely heavily on virtualization.

The LSA++ Layers

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Open Operational Data Store Layer

Entry point for data. Uses Field-based aDSOs or Open ODS Views to expose source data exactly as it is, without mapping to InfoObjects yet. Highly agile.

🗄️
Core Data Warehouse Layer

The "single version of truth." Data is cleansed, harmonized, and physically stored in InfoObject-based aDSOs. Historical tracking and delta mechanisms occur here.

🌐
Virtual Data Mart Layer

Replaces physical InfoCubes. This layer is entirely virtual, utilizing CompositeProviders to join and union data from the Core layer for reporting in SAP Analytics Cloud or Analysis for Office.

Data Modeling

InfoObjects

InfoObjects remain the semantic backbone of BW/4HANA, providing shared master data, texts, and hierarchies across the warehouse.

Characteristics vs. Key Figures

  • Characteristics: Represent business entities (e.g., Customer, Material, Cost Center). Can contain Attributes (properties), Texts (descriptions), and Hierarchies.
  • Key Figures: Represent quantifiable measures (e.g., Revenue, Quantity, Discount). Must be associated with a Currency or Unit of Measure.

BW/4HANA Enhancements to InfoObjects

While the concept of InfoObjects existed in legacy BW, BW/4HANA introduces several optimizations:

  • HANA Views: You can automatically generate an external SAP HANA Calculation View for an InfoObject to consume its master data directly in native HANA SQL or third-party tools.
  • Enhanced Master Data Update: Master data can now be updated concurrently, removing legacy lock issues.
  • XXL Attributes: Support for Extra Extra Large attributes (like strings or raw data up to 2GB) attached to a characteristic.
Field-based vs. InfoObject-based Modeling: In BW/4HANA, you don't *have* to use InfoObjects everywhere. You can model aDSOs using simple database fields (like CHARACT or INTEGER). This allows for rapid prototyping (Open ODS Layer). However, for governed reporting and hierarchy usage, InfoObjects are still required.
Data Modeling

Advanced DSO (aDSO)

The Advanced DataStore Object (aDSO) is the central persistence (storage) object in BW/4HANA, replacing all legacy InfoCubes and classic DSOs.

aDSO Table Architecture

An aDSO consists of three underlying HANA tables (similar to the classic DSO, but highly optimized):

  1. Inbound Table (/BIC/A...1): Where newly loaded data lands first.
  2. Active Data Table (/BIC/A...2): The table containing the compressed, harmonized "current state" of the data.
  3. Change Log (/BIC/A...3): Records the delta (before/after images) during activation, used to supply delta records to downstream targets.

Modeling Properties (Templates)

When creating an aDSO in Eclipse, you select a template property that dictates how the object behaves. This determines which of the 3 tables are used.

Property NameLegacy EquivalentBehavior
Standard DSOStandard DSOData writes to Inbound table. Requires Activation step. Generates a Change Log for downstream deltas.
Staging DSOWrite-Optimized DSO / PSAData writes directly to Inbound table only. No activation required. Highly performant for initial ingestion.
Data Mart DSOInfoCubeData is activated, but aggregates directly into the Active table. No Change Log is generated. Used for multidimensional reporting.
Direct Update DSODirect Update DSOData is written directly to the Active table via APIs or planning functions. Used in BW-IP / BPC Embedded.
Data Modeling

CompositeProvider (HCPR)

The CompositeProvider is the universal virtual modeling object in BW/4HANA, replacing MultiProviders and InfoSets.

Core Functionality

A CompositeProvider (technically HCPR) does not store data. It executes UNION and JOIN operations on underlying physical providers (aDSOs, InfoObjects, or HANA Views) at query runtime using the speed of the HANA database.

JOIN vs. UNION:
• UNION: Appends data sets vertically. (e.g., combining Actuals from aDSO A and Plan data from aDSO B).
• JOIN: Appends data sets horizontally. Supports Inner, Left Outer, and Full Outer joins. (e.g., joining Sales Fact aDSO with a native HANA view containing external customer classifications).

Key Features

  • Graphical drag-and-drop editor in Eclipse.
  • Allows mapping of field-based data directly to InfoObjects at the virtual layer without writing physical transformation logic.
  • The primary consumption object for BW Queries (Analytics Engine).
Data Modeling

Open ODS Views

Open ODS Views enable agile, virtual access to external data sources without the need for physical data extraction (ETL).

Agile Data Warehousing

Traditionally, bringing a new flat file or database table into BW took weeks (create InfoObjects, build DataSource, build DSO, build transformations, load data). With an Open ODS View, you can virtually consume a HANA database table or a remote source (via Smart Data Access) immediately.

Capabilities

  • Field-Based: Exposes the raw structure of the source table.
  • Semantics: Allows you to define which fields are characteristics and which are key figures, without creating actual InfoObjects.
  • Swap Source: You can start virtually (pointing to a remote table), and later seamlessly swap the source to a physical aDSO without breaking the downstream reports.
Data Integration

ODP Framework (Operational Data Provisioning)

ODP is the strategic data extraction and replication framework in BW/4HANA, replacing traditional mechanisms like RSA7 delta queues and InfoPackages.

What is ODP?

ODP acts as a universal buffer (the Operational Delta Queue - ODQ) between source systems and BW/4HANA. It handles full and delta extractions highly efficiently, with built-in compression.

ODP Contexts (Source Types)

When creating a DataSource in BW/4HANA, you select an ODP Context based on the source:

ODP ContextUsed For
ODP-SAPIClassic SAP Extractors (e.g., 2LIS_02_ITM, 0FI_GL_4) from ECC or S/4HANA. Replaces the old RSA7 setup.
ODP-CDSExtracting data from ABAP Core Data Services (CDS) Views in S/4HANA. The modern way to extract S/4 data.
ODP-SLTTrigger-based real-time replication via SAP Landscape Transformation Replication Server.
ODP-BWExtracting data from another BW or BW/4HANA system.
InfoPackages are Obsolete: Because the PSA layer is gone, InfoPackages no longer exist in BW/4HANA. Data is loaded directly from the ODP source into the aDSO using a Data Transfer Process (DTP).
Data Integration

Transformations & AMDP

Transformations map and convert data between source and target objects. In BW/4HANA, this logic is pushed down to the HANA database for maximum performance.

HANA Pushdown (AMDP)

In classic BW, transformations ran in the ABAP application server. Data had to be extracted from the DB, moved to the App server, processed row-by-row, and written back to the DB. This was slow.

BW/4HANA utilizes ABAP Managed Database Procedures (AMDP). If a transformation meets certain criteria (no complex ABAP custom logic), the system automatically compiles the transformation into a HANA SQLScript procedure. The entire transformation executes inside the HANA database memory instantly.

Custom Routines

If you need custom logic (Start Routine, Field Routine, End Routine), you have two choices in BW/4HANA:

  • ABAP Routines: Classic ABAP. Forces the transformation to run on the ABAP server (slow).
  • AMDP Script Routines: Write the routine using HANA SQLScript. Keeps the transformation pushed-down to the DB layer (fast).
Data Integration

DTPs & Process Chains

Data Transfer Processes move the data, and Process Chains orchestrate the automation.

Data Transfer Process (DTP)

In BW/4HANA, the DTP is the only object used to move data. It extracts directly from the ODP source (bypassing the PSA) and loads through the transformation into the aDSO.

  • Delta Handling: The DTP communicates with the Operational Delta Queue (ODQ) to request only new/changed records.
  • Error Stack: If records fail transformation, they are written to the DTP Error Stack. After fixing the data, an "Error DTP" can be run to process only the failed records.

Process Chains

Process chains are the scheduling and orchestration tool. They string together DTPs, aDSO Activation steps, DTO tiering movements, and attribute change runs into automated nightly batch jobs.

Streaming Process Chains: BW/4HANA introduces "Streaming" chains. Instead of running on a fixed schedule (e.g., 2:00 AM), streaming chains execute continuously in near-real-time as soon as new delta records arrive in the ODP queue.
Reporting & Analytics

BW Queries (Analytic Engine)

BW Queries are built on top of CompositeProviders to define the reporting dataset for end-users, utilizing the powerful SAP BW Analytic Engine.

BW Query Designer in Eclipse

BEx Query Designer is retired. Queries are now built exclusively within the Eclipse BW Modeling Tools.

Key Analytic Engine Capabilities

FeatureDescription
Calculated Key Figures (CKF)Mathematical formulas executed at query runtime (e.g., Profit = Revenue - Cost).
Restricted Key Figures (RKF)A key figure pre-filtered by a characteristic (e.g., "Revenue" restricted to Year = 2024).
VariablesPrompts that ask the user for input (e.g., select a Region) before executing the query.
Exceptions & ConditionsExceptions highlight data (red/green) based on thresholds. Conditions filter the result set (e.g., "Top 10 Customers by Revenue").
Consumption: BW Queries are consumed directly by SAP Analytics Cloud (via Live Connection) or SAP Analysis for Microsoft Office.
Administration

Data Tiering Optimization (DTO)

HANA in-memory storage is expensive. DTO is a framework to automatically move older, less frequently accessed data to cheaper storage tiers based on rules.

The Temperature Concept

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HOT

Storage: SAP HANA In-Memory.
Data: Highly accessed, recent data.
Performance: Maximum.

☀️
WARM

Storage: SAP HANA Extension Node / Native Storage Extension (NSE - disk).
Data: Less frequently accessed.
Performance: Slightly reduced.

❄️
COLD

Storage: SAP IQ (Near-line Storage - NLS) or Hadoop.
Data: Historical data required for compliance.
Performance: Slow, read-only.

How DTO Works

In the aDSO settings, you enable DTO and select a partitioning field (usually a Date or Time characteristic). You then define temperature rules (e.g., "Data older than 2 years moves to WARM. Data older than 5 years moves to COLD"). A DTO background job executes these rules, physically moving the partitions behind the scenes. The data remains completely transparent to the BW Query—the Analytic Engine knows where to find it.

Administration

BW/4HANA Cockpit

The web-based SAP Fiori interface used for monitoring and administrating the BW/4HANA system.

Replacing SAP GUI (RSA1)

While modeling moved to Eclipse, administration moved to the Web. The BW/4HANA Cockpit provides Fiori tiles for:

  • Process Chain Monitoring: Visual flowcharts of running chains, with error tracking and restart capabilities.
  • Data Volume Management: Dashboards showing which aDSOs are consuming the most HANA memory, assisting with DTO strategies.
  • Manage aDSOs: Activating data, deleting requests, and managing the active/inbound tables.
  • Connections: Managing Source Systems (ODP, HANA, SDA).
Administration

Migration Paths

Moving from a legacy BW system (7.x) to BW/4HANA requires converting legacy objects (InfoCubes) to BW/4HANA optimized objects (aDSOs).

The Three Transition Paths

PathScenarioProcess
In-Place ConversionCurrent system is already BW on HANA and highly standardized.System is kept intact. Legacy objects are converted to aDSOs using the Transfer Tool within the same system, step-by-step.
Remote ConversionCurrent system is messy, but you want to keep existing data and models.Build a brand new, empty BW/4HANA system. Use the Transfer Tool to import data models and historical data over the network from the old system, converting them on the fly.
Shell ConversionGreenfield approach.Similar to Remote, but only the metadata (structure) is moved and converted. No historical data is transferred. Data is re-loaded from the source systems.
SAP Readiness Check: Before any migration, SAP provides a Readiness Check tool that analyzes the legacy BW system and flags custom ABAP code or obsolete objects that will break in BW/4HANA.
Quick Reference

Interview Quick Reference

Key concepts and common interview questions for SAP BW/4HANA.

Key Terms to Know Cold

  • LSA++: Layered Scalable Architecture optimized for HANA, utilizing virtual layers to reduce physical data copies.
  • aDSO: Advanced DataStore Object. The central persistence object replacing InfoCubes and classic DSOs. Has Inbound, Active, and Change Log tables.
  • CompositeProvider (HCPR): Virtual object that executes UNIONs and JOINs at query runtime.
  • ODP: Operational Data Provisioning. The new extraction framework bypassing the PSA.
  • AMDP: ABAP Managed Database Procedures. Pushes transformation logic down to the HANA DB.
  • DTO: Data Tiering Optimization. Moving data between Hot, Warm, and Cold storage automatically.

Common Interview Questions

  1. What are the major simplifications in BW/4HANA compared to BW 7.4/7.5? (Explain object reduction).
  2. What are the different modeling properties (templates) available for an aDSO, and what legacy objects do they replace?
  3. Explain the difference between a JOIN and a UNION in a CompositeProvider.
  4. Why is there no PSA in BW/4HANA, and how is data extraction handled instead?
  5. What is HANA Pushdown, and how do AMDP transformations contribute to it?
  6. How does Data Tiering Optimization (DTO) differ from classic Near-Line Storage (NLS)?
  7. What is an Open ODS View, and in which LSA++ layer would you use it?
  8. Describe the difference between an In-Place conversion and a Remote conversion to BW/4HANA.