Glossary · Database

Query Latency

Query latency is the time between submitting a database query and receiving its results.

Query latency determines whether data exploration feels like a conversation or a chore. Sub-second responses keep people asking follow-up questions; thirty-second waits end the session. Latency comes from several places–query complexity, missing indexes, table size, network distance, and load on the database–and in AI query tools there is an extra component: the time the model takes to generate the SQL. Why it matters commercially: analytics that people actually use is analytics that responds fast, and chronically slow queries against a production database can also degrade the application that database serves, which is why heavy analytics often runs on a read replica.

Fig — every answer ships with the tables, rows and SQL behind it.