Oracle Database 19c: Data Warehousing Techniques — Lesson 2: ETL and ELT Loading, External Tables, SQL*Loader, Direct Path, and Merge

Learning Objectives

• Explain the architecture, workflow, or business purpose behind staging layers, load windows, dependencies, and restartability.
• Apply external tables, SQL*Loader conventional and direct-path concepts and INSERT APPEND, parallel DML, MERGE, and set-based transformation in a controlled scenario.
• Validate outcomes and troubleshoot risks involving error logging, reject handling, reconciliation, audit columns, and load evidence.

Detailed Topics

• staging layers, load windows, dependencies, and restartability
• external tables, SQL*Loader conventional and direct-path concepts
• INSERT APPEND, parallel DML, MERGE, and set-based transformation
• error logging, reject handling, reconciliation, audit columns, and load evidence

Instructor Demonstration

Demonstrate staging layers, load windows, dependencies, and restartability within a growing sales warehouse redesigned for faster loads, predictable refreshes, and responsive analytical queries, then capture the exact configuration, command, transaction, report, model, query, code, or process evidence that proves the result for lesson 2.

Hands-On Exercise

Implement a controlled exercise covering external tables, SQL*Loader conventional and direct-path concepts and INSERT APPEND, parallel DML, MERGE, and set-based transformation, then introduce and resolve an exception involving error logging, reject handling, reconciliation, audit columns, and load evidence while preserving before-and-after evidence.

1. Confirm the environment, identities, inputs, dependencies, risks, and expected outcome.
2. Complete the course-specific configuration, development, analysis, or process workflow.
3. Capture settings, commands, data, outputs, logs, reports, screenshots, calculations, or test results.
4. Compare the observed result with acceptance criteria and document corrective action.

Scenario Analysis

• Identify the technical or business decision that must be made.
• Compare valid approaches and their security, performance, reliability, cost, compliance, and support trade-offs.
• Define rollback, recovery, ownership, communication, and evidence requirements.

Troubleshooting Guidance

Diagnose issues across staging layers, load windows, dependencies, and restartability, external tables, SQL*Loader conventional and direct-path concepts, INSERT APPEND, parallel DML, MERGE, and set-based transformation, error logging, reject handling, reconciliation, audit columns, and load evidence without making an unverified production change. Separate symptoms from causes, gather evidence, test the smallest reversible correction, rerun validation, and record preventive action.

Validation Checklist

• The requirement, scope, inputs, dependencies, and expected result are documented.
• The result is reproducible and supported by course-specific evidence.
• Normal, boundary, failure, security, performance, and operational conditions are reviewed.
• Exceptions, rollback, ownership, and the next improvement priority are recorded.

Lesson Outcome

Learners can apply ETL and ELT Loading, External Tables, SQL*Loader, Direct Path, and Merge in a realistic Oracle Database 19c: Data Warehousing Techniques scenario and validate the result with documented evidence.