Considerations when using Amazon Redshift Serverless - Amazon Redshift

Considerations when using Amazon Redshift Serverless

For a list of AWS Regions where the Amazon Redshift Serverless is available, see the endpoints listed for Redshift Serverless API in the Amazon Web Services General Reference.

Some resources used by Amazon Redshift Serverless are subject to quotas. For more information, see Quotas for Amazon Redshift Serverless objects.

When you DECLARE a cursor, the result-set size specifications for Amazon Redshift Serverless is specified in DECLARE.

Maintenance window – There is no maintenance window with Amazon Redshift Serverless. Software version updates are automatically applied. There's no interruption for existing connection or query execution when Amazon Redshift switches versions. New connections will always connect and work with Amazon Redshift Serverless instantly.

Availability Zone IDs – When you configure your Amazon Redshift Serverless instance, open Additional considerations, and make sure that the subnet IDs provided in Subnet contain at least three of the supported Availability Zone IDs. To see the subnet to Availability Zone ID mapping, go to the VPC console and choose Subnets to see the list of subnet IDs with their Availability Zone IDs. Verify that your subnet is mapped to a supported Availability Zone ID. To create a subnet, see Create a subnet in your VPC in the Amazon VPC User Guide.

Three subnets – You must have at least three subnets, and they must span across three Availability Zones. For example, you might use three subnets that map to the Availability Zones us-east-1a, us-east-1b, and us-east-1c. An exception to this is the US West (N. California) Region. It requires three subnets, in the same manner as the other regions, but these must span across only two Availability Zones. A condition is that one of the Availability Zones spanned must contain two of the subnets.

Free IP address requirements – You must have free IP addresses available when you create an Amazon Redshift Serverless workgroup. The minimum number of IP addresses scales higher as the number of Redshift Processing Units (RPUs) for the workgroup increases. Specifically, each subnet in your workgroup's VPC requires a minimum number of IP addresses. For more information on allocating IP addresses, see IP addressing in the Amazon VPC User Guide.

The number of minimum free IP addresses required when creating a workgroup are as follows:

Number of free IP addresses required for each subnet
Redshift Processing Units (RPUs) Free IP addresses required Minimum CIDR size
8 9 /27
16 15 /27
32 13 /27
64 21 /27
128 37 /26
256 69 /25
512 133 /24

You also need free IP addresses when updating your workgroup to use more RPUs. The number of free IP addresses required when updating the subnets for a workgroup are as follows:

Number of free IP addresses required when updating a subnet
Redshift Processing Units (RPUs) Updated Redshift Processing Units (RPUs) Free IP addresses required
8 16 10
16 32 13
32 64 16
64 128 28
128 256 52
256 512 100

Storage space after migration – When migrating small Amazon Redshift provisioned clusters to Amazon Redshift Serverless, you might see an increase in storage-space allocation after migration. This is a result of optimized storage-space allocation, resulting in preallocated storage space. This space is used over a period of time as data grows in Amazon Redshift Serverless.

Datasharing between Amazon Redshift Serverless and Amazon Redshift provisioned clusters – When datasharing where Amazon Redshift Serverless is the producer and a provisioned cluster is the consumer, the provisioned cluster must have a cluster version later than 1.0.38214. If you use a cluster version earlier than this, an error occurs when you run a query. You can view the cluster version on the Amazon Redshift console on the Maintenance tab. You can also run SELECT version();.

Max query execution time – Elapsed execution time for a query, in seconds. Execution time doesn't include time spent waiting in a queue. If a query exceeds the set execution time, Amazon Redshift Serverless stops the query. Valid values are 0–86,399.

Migrating for tables with interleaved sort keys – When migrating Amazon Redshift provisioned clusters to Amazon Redshift Serverless, Redshift converts tables with interleaved sort keys and DISTSTYLE KEY to compound sort keys. The DISTSTYLE doesn't change. For more information on distribution styles, see Working with data distribution styles in the Amazon Redshift Developer Guide. For more information on sort keys, see Working with sort keys.

VPC sharing – You can create Amazon Redshift Serverless workgroups in a shared VPC. If you do so, we recommend that you don't delete the resource share as it can result in the workgroup becoming unavailable.