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Limits in Amazon Redshift

Quotas and Limits

Amazon Redshift has quotas that limit the total number of nodes that you can provision, and the number of snapshots that you can create; these quotas are per AWS account per region. Amazon Redshift has a default quota for each of these, which are listed at AWS Service Limits. If you attempt to exceed any of these quotas, the attempt will fail. To increase these Amazon Redshift quota limits for your account in a region, request a change by submitting an Amazon Redshift Limit Increase Form.

In addition to quotas, Amazon Redshift has limits for the following per-cluster values. These limits cannot be increased:

• The number of nodes that you can allocate per cluster, which is based on the cluster's node type. This limit is separate from the limit for your AWS account per region. For more information about the current node limits for each node type, see Clusters and Nodes in Amazon Redshift.

• The maximum number of tables is 9,900 for large and xlarge cluster node types and 20,000 for 8xlarge cluster node types. The limit includes temporary tables. Temporary tables include user-defined temporary tables and temporary tables created by Amazon Redshift during query processing or system maintenance. Views are not included in this limit. For more information about creating a table, see Create Table Usage Notes in the Amazon Redshift Database Developer Guide. For more information about cluster node types, see Clusters and Nodes in Amazon Redshift.

• The number of user-defined databases you can create per cluster is 60. For more information about creating a database, see Create Database in the Amazon Redshift Database Developer Guide.

• The number of schemas you can create in each database in a cluster is 9,900, however, pg_temp_* schemas do not count towards this quota. For more information about creating a schema, see Create Schema in the Amazon Redshift Database Developer Guide.

• The number of concurrent user connections that can be made to a cluster is 500. For more information, see Connecting to a Cluster in the Amazon Redshift Cluster Management Guide.

• A workload management (WLM) configuration can define a total concurrency level of 50 for all user-defined queues. For more information, see Defining Query Queues in the Amazon Redshift Database Developer Guide.

• The number of AWS accounts you can authorize to restore a snapshot is 20 for each snapshot and 100 for each AWS Key Management Service (AWS KMS) key. That is, if you have 10 snapshots that are encrypted with a single KMS key, then you can authorize 10 AWS accounts to restore each snapshot, or other combinations that add up to 100 accounts and do not exceed 20 accounts for each snapshot. For more information, see Sharing Snapshots in the Amazon Redshift Cluster Management Guide.

• The maximum size of a single row loaded by using the COPY command is 4 MB. For more information, see COPY in the Amazon Redshift Database Developer Guide.

• A maximum of 10 IAM roles can be associated with a cluster to authorize Amazon Redshift to access other AWS services on behalf of the user that owns the cluster and IAM role. For more information, see Authorizing Amazon Redshift to Access Other AWS Services on Your Behalf.

Spectrum limits

Amazon Redshift Spectrum has the following limits when using the Athena or AWS Glue data catalog:

• A maximum of 10,000 databases per account.

• A maximum of 100,000 tables per database.

• A maximum of 1,000,000 partitions per table.

• A maximum of 10,000,000 partitions per account.

• All S3 data must be located in the same region as the Redshift cluster.

• Timestamps in ION and JSON must use ISO8601 format.

• The maximum allowed size of a row object in a ION/JSON file is 8MB.

  Objects in ION or JSON files are the data enclosed by brackets, for example (`{ "col1": "data1", "col2": "data2" }`).

• The maximum allowed size of a string value in an ION or JSON file is 16KB.

• External compression of ORC files is not supported.

• Text, OpenCSV and Regex SERDEs do not support octal delimiters larger than `\177`

• You must specify a predicate on the partition column to avoid reads from all partitions.

  For example, the following predicate will filter on the column ship_dtm but will not apply the filter to the partition column ship_yyyymm:

  WHERE ship_dtm > '2018-04-01'.

  To skip unneeded partitions you need to add a predicate WHERE ship_yymmm = '201804'. This predicate will limit read operations to the partition \ship_yyyymm=201804\.

• The column limit for external tables is 1598 with pseudo columns enabled and 1600 without.

You can request a limit increase by contacting AWS Support.

These limits don’t apply to a Hive metastore.

Naming Constraints

The following table describes naming constraints within Amazon Redshift.

Cluster identifier	A cluster identifier must contain only lowercase characters. It must contain from 1 to 63 alphanumeric characters or hyphens. Its first character must be a letter. It cannot end with a hyphen or contain two consecutive hyphens. It must be unique for all clusters within an AWS account.
Database name	A database name must contain 1 to 64 alphanumeric characters. It must contain only lowercase letters. It cannot be a reserved word. For a list of reserved words, see Reserved Words in the Amazon Redshift Database Developer Guide.
Master user name	A master user name must contain only lowercase characters. It must contain from 1 to 128 alphanumeric characters. Its first character must be a letter. It cannot be a reserved word. For a list of reserved words, see Reserved Words in the Amazon Redshift Database Developer Guide.
Master password	A master password must be between 8 and 64 characters in length. It must contain at least one uppercase letter. It must contain at least one lowercase letter. It must contain one number. It can be any printable ASCII character (ASCII code 33 to 126) except ' (single quotation mark), " (double quotation mark), \, /, @, or space.
Parameter group name	A parameter group name must be 1 to 255 alphanumeric characters or hyphens. It must contain only lowercase characters. Its first character must be a letter. It cannot end with a hyphen or contain two consecutive hyphens.
Cluster security group name	A cluster security group name must contain no more than 255 alphanumeric characters or hyphens. It must contain only lowercase characters. It must not be Default. It must be unique for all security groups that are created by your AWS account.
Subnet group name	A subnet group name must contain no more than 255 alphanumeric characters or hyphens. It must contain only lowercase characters. It must not be Default. It must be unique for all security groups that are created by your AWS account.
Cluster snapshot identifier	A cluster snapshot identifier must contain no more than 255 alphanumeric characters or hyphens. It must contain only lowercase characters. It must not be Default. It must be unique for all security groups that are created by your AWS account.