SQL Server 2017 end of support

The instance keeps working — nothing stops on the day, which is exactly what makes this easy to defer. What stops is security updates, so any vulnerability disclosed after 12 October 2027 stays unpatched. You also lose the ability to raise a Microsoft support case, and you will fail patch-currency expectations under the ACSC Essential Eight and most enterprise supply-chain reviews.

Comfortably, if the application work starts now. A year is roughly one budget cycle plus one vendor certification round plus one change freeze. The database migration itself is usually a single change window; the time goes on confirming which SQL Server version each application vendor certifies, and on testing against a restored copy. Upgrades that miss the date almost always miss it because that started late.

It depends on the application, not the database. Upgrading in place is usually cheapest over three years and keeps everything familiar to your team. Azure SQL Managed Instance ends the upgrade treadmill permanently because Microsoft patches the platform, but it needs the application to tolerate a small set of T-SQL differences. We test compatibility before recommending either, rather than after.

ESUs are paid security patches that continue after extended support ends, for up to three further years. They are a bridge, not a destination — the cost rises each year and the version keeps ageing. They make sense when a migration is genuinely planned and dated, and they are expensive when used to avoid making the decision. Confirm current pricing and eligibility with your licensing partner, because ESU terms change.

Near-zero downtime is achievable using Always On availability groups or log shipping — moving the workload to the upgraded instance and cutting over. Whether that is worth the extra complexity depends on what an hour of downtime actually costs you, and we will tell you honestly when it is not.

Onsys consultants based in Australia. Database work is Australian-only: every login to a client database instance is made by an Australian-based Onsys DBA, and no offshore engineer holds credentials to a client database. Upgrades run as fixed-price projects, scoped after the assessment so the price reflects your estate rather than an assumption about it.