AWS Database Blog

Category: Best Practices

Resolving PostgreSQL replication lag with heartbeat tables in change data capture scenarios

Resolving PostgreSQL replication lag with heartbeat tables in change data capture scenarios

Replication lag during a change data capture (CDC) migration can be counterintuitive: the source is busy, yet replication falls behind and WAL piles up. This post shows how to resolve PostgreSQL replication lag with heartbeat tables using AWS DMS or Debezium, and how to monitor replication slot health with Amazon CloudWatch and SQL diagnostics.

Resolving query plan regressions after a MySQL engine upgrade

Resolving query plan regressions after a MySQL engine upgrade

After a major or minor version upgrade on Amazon Aurora MySQL or Amazon RDS for MySQL, some queries regress because the optimizer’s cost models, defaults, and execution strategies change. This post walks through a diagnostic workflow that traces each regression to the specific version change behind it and applies the right fix.

Getting started with Oracle Database@AWS: A complete onboarding guide

Getting started with Oracle Database@AWS: A complete onboarding guide

A practical, step-by-step guide to getting Oracle Database@AWS up and running. It covers the five procurement and onboarding steps, from securing your AWS Marketplace offer through validating prerequisites, linking your OCI tenancy, and configuring IAM, so you can move from purchase to a provisioning-ready environment.

Characterizing SQL*Net latency in your application for Oracle Database@AWS migrations

Oracle Database@AWS places Oracle Exadata infrastructure inside AWS data centers, so SQL*Net latency between your application and the database can change after migration. This post presents the CRET methodology, a three-phase approach using AWR, Active Session History, and SQL Trace, to identify latency-sensitive SQL and quantify the impact before you migrate.

Build zero-downtime write architectures for Amazon Neptune

Build zero-downtime write architectures for Amazon Neptune

Learn how to build zero-downtime write architectures for Amazon Neptune using a write queue pattern with Amazon SQS, Amazon Kinesis Data Streams, or Amazon MSK. By decoupling write acceptance from write execution, your application keeps accepting graph writes during maintenance windows, failovers, and scaling operations.

Detect CDC failures faster with AWS DMS

AWS DMS uses exponential backoff for recoverable errors, and default settings can let a change data capture (CDC) task retry silently for up to 30 minutes before failing. This post shows how to tune four recoverable-error settings so CDC tasks fail within minutes, and how to pair them with Amazon EventBridge and Amazon CloudWatch alerts.

Improve query performance with EXPLAIN plans in Amazon Aurora DSQL

In this post, we show you how to use EXPLAIN plans to diagnose and improve query performance in Amazon Aurora DSQL. We introduce a three-layer filter model as a practical framework for understanding where your predicates are evaluated, and walk through the architecture differences that make Aurora DSQL plans unique, the anatomy of an EXPLAIN output, access method selection, and a step-by-step query improvement workflow.

Pagination patterns in Amazon Aurora DSQL

In this post, you learn three pagination techniques for Aurora DSQL: OFFSET/LIMIT, cursor-based (keyset), and temporal. You implement keyset pagination in SQL and Python, build it into an API layer, optimize with composite indexes, handle batch processing within the 3,000-row transaction limit, and avoid five common anti-patterns. By the end, you can choose the right pagination method for your workload and implement it with confidence.