Database Migration & DMS

Migration Strategies & Tools

AWS DMS Overview

Minimal Downtime

Migrate with continuous data replication

Heterogeneous Migration

Different source and target engines

Homogeneous Migration

Same source and target engines

Continuous Replication

Ongoing data synchronization

Migration Types

Full Load

One-time migration of existing data

Full Load + CDC

Initial load plus ongoing changes

CDC Only

Replicate ongoing changes only

Test Connection

Validate connectivity and settings

Supported Sources & Targets

Relational Databases

Traditional SQL databases

  • • Oracle, SQL Server, MySQL
  • • PostgreSQL, MariaDB
  • • IBM Db2, SAP ASE

NoSQL Databases

Document and key-value stores

  • • MongoDB, DynamoDB
  • • Amazon DocumentDB
  • • Apache Cassandra

Data Warehouses

Analytics and reporting systems

  • • Amazon Redshift
  • • Snowflake, Vertica
  • • Azure Synapse

DMS Components

Replication Instance

EC2 instance running DMS software

Source Endpoint

Connection to source database

Target Endpoint

Connection to target database

Migration Task

Defines what data to migrate

Schema Conversion

AWS SCT

Schema Conversion Tool for heterogeneous migrations

Code Conversion

Convert stored procedures and functions

Assessment Report

Migration complexity analysis

Data Type Mapping

Automatic data type conversion

Migration Strategies

Lift and Shift

Minimal changes

Platform Change

Engine optimization

Refactor

Architecture changes

Hybrid Approach

Phased migration

Best Practices

Test Thoroughly

Validate data integrity and performance

Monitor Progress

Track migration metrics and logs

Plan Rollback

Prepare contingency procedures

Common Challenges

Large Object Migration

LOBs require special handling

Network Latency

Affects replication performance

Schema Differences

Engine-specific features

Migration Exam Tips

  • • DMS supports minimal downtime migrations with continuous data replication
  • • Use AWS SCT for heterogeneous migrations requiring schema conversion
  • • Full Load + CDC is most common for production migrations
  • • Replication instance size affects migration performance
  • • Test connections and validate data before cutover
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