# When should an application use a database read replica?

Canonical URL: https://help.iagenify.com/faqs/databases/when-should-an-application-use-a-database-read-replica

[← Back to Databases FAQs](https://help.iagenify.com/faqs/databases)

HELP CENTER · FAQ Databases 1 min read
# When should an application use a database read replica?
A read replica can serve eligible queries from a copy of the primary database, helping distribute workload when the database and application support that pattern. Replication is often asynchronous, so a replica may lag and should not automatically be treated as the source of the latest committed data.
IaGenify
Databases

## Route only reads that tolerate lag
Reports, search views, and queries where a short delay is acceptable are good candidates. Keep writes and read-after-write flows on the primary when users must immediately see a change they just made.
Measure replication lag and query health, and define what the application should do if the replica falls behind or becomes unavailable. Blind routing can return stale values or shift an outage elsewhere in the product.
## Validate consistency and cost
Test the database features and transaction behavior your application uses; not every query or session setting behaves identically across primary and replica. Check provider documentation for supported modes and failover limits.
Compare benefits with extra compute, storage, network, and monitoring costs. A replica is not a backup: deletion or corruption may replicate, so keep independent backups and test restores. [← Back to Databases FAQs](https://help.iagenify.com/faqs/databases)