awsredshiftdatacost-optimization

AWS Redshift Serverless cost: you pay per RPU-hour of query time

Redshift Serverless bills per Redshift Processing Unit (RPU) hour while queries run, plus managed storage, with no cluster to pause. It suits variable, intermittent analytics; steady heavy load is cheaper on a provisioned cluster. Here is how to size it.

The C3X Team··5 min read

Quick answer

Redshift Serverless bills per RPU-hour (Redshift Processing Unit) while queries run, metered per second with a minimum, plus managed storage per GB-month. It scales capacity to the workload with nothing to pause. Serverless suits variable, intermittent analytics; a provisioned cluster (with reservations) is cheaper for steady, heavy query load.

Redshift Serverless removes cluster management from data warehousing: instead of provisioning nodes, you pay for the compute your queries consume, measured in RPUs. The convenience is priced, so the decision against a provisioned cluster is the familiar variable-versus-steady tradeoff.

RPU-hours and storage

You set a base capacity in RPUs and pay per RPU-hour, metered per second with a minimum charge per query burst, only while queries run. Idle periods cost nothing for compute. Storage is managed and billed per GB-month separately. So a warehouse queried in bursts pays for those bursts, not for a cluster sitting idle overnight.

Serverless vs provisioned

ModeBills forBest when
ServerlessRPU-hours while querying + storageVariable, intermittent, spiky
ProvisionedNode-hours, always onSteady, heavy, predictable

Serverless wins when query load is variable or the warehouse is often idle, since you avoid paying for provisioned nodes doing nothing. A provisioned cluster, especially with reserved nodes, is cheaper for steady, heavy, predictable query volume, the same crossover as Redshift versus Athena.

Controlling serverless cost

Set a sensible base RPU capacity and a maximum so a runaway query cannot scale cost without bound, and use the usage limits and alerts to cap spend. Reduce RPU-hours the same way you reduce any query cost: good table design, sort and distribution keys, and avoiding scans of data you do not need. If a serverless workload grows into steady heavy use, re-evaluate against a provisioned cluster.

FAQ

How is Redshift Serverless priced?

Per RPU-hour (Redshift Processing Unit) while queries run, metered per second with a minimum, plus managed storage per GB-month. Idle periods cost nothing for compute, so a warehouse queried in bursts pays for those bursts rather than an always-on cluster.

Is Redshift Serverless cheaper than a provisioned cluster?

For variable, intermittent, or often-idle query load, yes, because you avoid paying for provisioned nodes sitting idle. For steady, heavy, predictable load a provisioned cluster, especially with reserved nodes, is cheaper. Match the mode to your query pattern.

What is an RPU?

A Redshift Processing Unit, the compute-billing unit for Redshift Serverless. You set a base RPU capacity and pay per RPU-hour while queries run. More RPUs mean more parallelism and cost, so sizing the base and maximum controls spend.

How do I cap Redshift Serverless cost?

Set a base RPU capacity and a maximum so a runaway query cannot scale cost without bound, and configure usage limits and alerts to cap spend. Reduce RPU-hours with good table design, sort and distribution keys, and avoiding unnecessary scans.

When should I switch to a provisioned Redshift cluster?

When query load becomes steady and heavy enough that always-on provisioned nodes, especially reserved, cost less than the RPU-hours a serverless workload of the same volume would consume. As load grows and stabilizes, provisioned becomes cheaper.

Does C3X estimate Redshift cost?

C3X prices provisioned Redshift clusters from your Terraform directly. For Serverless, cost depends on RPU-hours consumed by queries, which is a usage input you model, plus managed storage that scales with data volume.

What to do next

Compare serverless and provisioned before you choose. C3X reads your Terraform and prices Redshift and the rest of your stack against a live catalog. Start with the quickstart.

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