Data reconciliation is a process that verifies data migration by comparing source and target data to ensure correct transfer. It has three key steps: capture source data, scrub data by validating, standardizing, and enhancing values, and transform data into the target schema and structure before loading into the data warehouse. Reconciled data forms the single authoritative source for decision making, while derived and aggregated data are formatted views of reconciled data to support end users.

1. Data Warehouse: 12
Reconciled Data Layers
Prof Neeraj Bhargava
Vaibhav Khanna
Department of Computer Science
School of Engineering and Systems Sciences
Maharshi Dayanand Saraswati University Ajmer

2. What is Data Reconciliation?
• Data reconciliation
• (DR) is defined as a process of verification
of data during data migration. In this process
target data is compared with source data to
ensure that the migration architecture is
transferring data correctly.

3. Reconciled and derived data
• Reconciled data: detailed, current data intended
to be the single, authoritative source for all
decision support.
• Derived data: Data that have been selected,
realigned, formatted, and aggregated for end-
user decision support application. (generally in
the form of Materialized Views)
• Metadata: technical and business data that
describe the properties or characteristics of other
data.

4. Three layered Architecture

5. Data Characteristics
Status vs. Event Data

6. Transient vs Periodic Data
• In the case of transient
(operational)data the
changes to existing records
are written over previous
records, thus destroying the
previous data content
• Whereas in Periodic Data of
Data Warehouse, the Data
are never physically altered
or deleted once they have
been added to the store

7. Steps in data reconciliation: Capture

8. Steps in data reconciliation: Scrub

9. Steps in Data Reconciliation: Transform

10. Steps in Data Reconciliation: Load

11. Assignment
• 1. What is data Reconciliation. Briefly discuss
the steps in data reconciliation during ETL
• Thank You