These days, there’s no shortage of database options. Modern databases promise built-in scalability, automatic failover, and serverless everything. Many claim they’re compatible with the system you’re using today. Just export your data, point your app to the new solution, and you’re good to go.
But if your database is already in production, with real customers, data pipelines, alerts, cron jobs, and internal teams relying on it, then a migration is rarely straightforward.
Let’s look at what makes database migrations painful, best practices for switching systems, and when it’s worth considering alternatives that don’t require tearing everything down.
Most migration guides make it sound simple. Dump the data, import it into the new system, change a connection string, test a few queries, and you’re done.
And sure, if you’re migrating a side project, an internal tool, or a dev instance with minimal traffic, it can be straightforward.
But production databases are rarely that simple. They’re tied into background jobs, metrics pipelines, customer workflows, dashboards, data exports, and all kinds of internal tooling.
Replacing such a database isn’t just a technical task. It’s an exercise in uncovering everything that quietly depends on it, and making sure none of it breaks along the way.
Copying data sounds simple until you're doing it at scale. Terabytes take time, and transfers can bog down your primary. If the job crashes halfway through, you have to validate what was copied and what wasn’t. Write-ahead logs (WAL) can balloon if replication falls behind, which starts affecting other workloads.
You can’t shut down a production database while you migrate to a new one, which means you need some way to keep them in sync until you’re confident the new system is ready to take over.
Here’s a breakdown of the usual approaches:
Even if the new database claims compatibility, plenty can still break:
And beyond queries, you also have to coordinate things like:
Staging environments can’t always recreate real-world usage patterns. Everything that touches the database needs to be tested, ideally under production-like conditions, including:
When teams start planning a database migration, they often think in terms of days or weeks. The reality depends heavily on your scale and complexity.
For smaller organizations with straightforward setups (a single application, minimal background jobs, and a small team), migrations can happen relatively quickly. A few weeks of planning, testing, and execution might be enough.
But for mature organizations with production databases that have grown over time, timelines can stretch significantly. This includes planning and dependency mapping, setting up replication and testing, coordinating with other teams, validating everything under load, and managing cutover and post-migration.
And engineering cost scales with complexity too. A simple migration might need one engineer for a few weeks. A complex one can easily consume months across multiple roles and teams: from senior engineers to DevOps, QA, and DBAs.
That represents a significant opportunity cost.
While your team is deep in migration work, they are not shipping features, fixing bugs, or improving other parts of the system. The migration becomes a full-time project that delays everything else by months.
If you do decide to proceed with a migration, preparation is crucial.
In particular, it helps to think beyond the schema and the data itself. A production database is surrounded by tooling, workflows, and systems. Monitoring, backups, alerting, and pipelines can break in subtle ways when you swap out the underlying database.
Systems and tools to review before cutover:
And then there’s the impact on your customers. Early-stage teams might get away with being cavalier, but mature organizations with significant customers need a serious rollout plan.
If your migration requires downtime, build a plan that includes:
Even when compatibility seems solid, real workloads can reveal problems. Here are some of the issues that tend to slip through early validation:
Individually, these issues might seem small. But they add up, especially in production systems that have grown over time.
The tricky part is that many of these problems don’t surface right away. A job might run fine for days before failing. A dashboard might return bad data without throwing an error. A background job might silently skip over the records it’s supposed to process.
Some migrations are necessary. Maybe your current system is being deprecated. Maybe you’re under new compliance requirements, or shifting to a completely different architecture. If the need is clear and the benefits are long-term, it might be worth the time and effort.
But most of the time, teams aren’t migrating for those reasons.
They’re migrating because reads are getting slow, costs are going up, or infrastructure is getting harder to manage.
We ran into this ourselves.
At our previous SaaS company, we hit the limits of our Postgres database powering near-realtime analytics dashboards. Hourly jobs updated large tables with web traffic data, while users triggered complex analytical queries against those same tables. These read and write workloads clashed, causing slow queries and delayed dashboards.
We explored migrating the data to a warehouse, but the complexity of syncing customer data and rewriting queries held us back. Read replicas sounded easier, but still required proxying or application changes to support.
In the end, we made smaller optimizations to buy us more time. But that experience is what inspired us to build Springtail.
Springtail adds elastic read capacity to your existing Postgres database without requiring a migration, schema changes, or new infrastructure to manage. If your bottleneck is read traffic, Springtail can give you more capacity without the risk and burden of a full cutover.
Before you commit to a database migration, it’s worth asking what you are actually trying to improve. If the answer is performance, scalability, or manageability, you might not need to start over. You might just need a better way to extend what you already have.
Explore our docs or book a demo to get started.
