In SAP ABAP Data Dictionary, what is the difference between transparent tables and pooled tables?

Introduction / Context:
SAP uses different table types in the ABAP Data Dictionary to optimize storage and performance. Two important types are transparent tables and pooled tables. Interviewers often ask this question to see whether you understand how these table types map to the underlying database and what kind of data they store. Knowing the difference matters when analyzing SQL traces, troubleshooting performance, or designing new tables.

Given Data / Assumptions:

• Transparent tables are used mainly for application data such as master and transaction records.
• Pooled tables belong to table pools and are used for many small logical tables.
• The database underneath SAP is a relational database such as Oracle, SQL Server, or HANA.
• The question focuses on mapping and typical usage, not every technical setting.

Concept / Approach:
A transparent table has a direct, one to one relationship with a physical table in the database. The table name and structure in the ABAP Data Dictionary match the table name and columns in the database. This makes it straightforward for SQL based tools to access the data. Pooled tables, however, are many logical tables combined into a single physical table called a table pool. Each record in the pool contains information that identifies which pooled table it belongs to and stores the data in a compact way. Pooled tables are typically used for control, customizing, or temporary configuration data and are less common in modern SAP installations, especially with newer database technologies.

Step-by-Step Solution:
Step 1: Recall that transparent tables map directly to real database tables with the same name and structure. Step 2: Remember that pooled tables are grouped together in a table pool, so multiple logical ABAP tables share one physical table. Step 3: Look for the option that explicitly states this one to one versus many to one mapping and mentions typical data usage. Step 4: Option A correctly describes that transparent tables hold application data in one to one mapping, while pooled tables group many logical tables in a single physical pool.

Verification / Alternative check:
You can verify by thinking about how external reporting tools see SAP tables. Transparent tables are visible directly in the database catalog and can be queried by name. Pooled tables are not visible individually; instead, only the pool table appears. To interpret entries, you must know the pool structure. This confirms that only transparent tables have a one to one mapping. In addition, modern design guidelines recommend using transparent tables for most application data, while pooled tables are often reserved for special system uses.

Why Other Options Are Wrong:
Option B is wrong because buffering is a technical setting that can apply to transparent tables, and pooled tables are not always fully buffered. Option C is incorrect because business critical data such as orders or materials is stored in transparent tables, not pooled tables. Option D reverses the mapping and is factually incorrect. Option E is wrong because views and indexes are separate objects and are not used to distinguish between transparent and pooled tables.

Common Pitfalls:
A common pitfall is to assume that all ABAP Dictionary tables behave the same in the database. Another mistake is to think pooled tables are suitable for large transactional datasets, which can cause performance issues. Understanding the structural differences between transparent and pooled tables helps you interpret SQL traces correctly and design data models that work well with the underlying database.

Final Answer:
A transparent table has a one to one mapping to a physical database table for application data, while pooled tables are many logical tables stored together in one physical pool table for control and customizing data