# Limits for Neptune Analytics
<a name="analytics-limits"></a>

## Regions
<a name="limits-regions"></a>

Neptune Analytics is available in the following AWS Regions:
+ US East (N. Virginia):   `us-east-1`
+ US East (Ohio):   `us-east-2`
+ US West (N. California):   `us-west-1`
+ US West (Oregon):   `us-west-2`
+ Asia Pacific (Singapore):   `ap-southeast-1`
+ Asia Pacific (Sydney):   `ap-southeast-2`
+ Asia Pacific (Malaysia):   `ap-southeast-5`
+ Asia Pacific (Tokyo):   `ap-northeast-1`
+ Asia Pacific (Seoul):   `ap-northeast-2` (Note: `ap-northeast-2d` Availability Zone is not available)
+ Asia Pacific (Osaka):   `ap-northeast-3`
+ Asia Pacific (Mumbai):   `ap-south-1`
+ Asia Pacific (Hong Kong):   `ap-east-1`
+ Europe (Ireland):   `eu-west-1`
+ Europe (London):   `eu-west-2`
+ Europe (Paris):   `eu-west-3`
+ Europe (Frankfurt):   `eu-central-1`
+ Europe (Zurich):   `eu-central-2`
+ Europe (Stockholm):   `eu-north-1`
+ Canada (Central):   `ca-central-1`
+ Canada West (Calgary):   `ca-west-1`
+ South America (São Paulo):   `sa-east-1`
+ Middle East (Bahrain):   `me-south-1`
+ Middle East (UAE):   `me-central-1`
+ Israel (Tel Aviv):   `il-central-1`
+ Africa (Cape Town):   `af-south-1`

**Note**  
Neptune Analytics is not available in the AWS GovCloud (US-West) or AWS GovCloud (US-East) Regions.

## Quotas
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Your AWS account has default quotas, formerly referred to as limits, for each AWS service. Unless otherwise noted, each quota is Region-specific. You can request increases for some quotas, and other quotas cannot be increased.

To view the quotas for Neptune Analytics, open the [Service Quotas console](https://console.aws.amazon.com/servicequotas/home). In the navigation pane, choose **AWS services** and select **Neptune Analytics**.

To request a quota increase, see [Requesting a Quota Increase](https://docs.aws.amazon.com/servicequotas/latest/userguide/request-quota-increase.html) in the *Service Quotas User Guide*. If the quota is not yet available in Service Quotas, use the [limit increase form](https://console.aws.amazon.com/support/home#/case/create?issueType=service-limit-increase).

## Vertex enumeration is not memory bounded
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The following quotas and limits apply to Neptune Analytics:

The current implementation of vertex enumeration and counting is not memory bounded. As a consequence, queries such as `MATCH (n) RETURN count(n)` will require a significant amount of memory and, depending on the chosen capacity and dataset shape, may run into out-of-memory exceptions.

Where possible, we recommend replacing such queries with queries that operate on a per-label basis. For instance, a query such as `MATCH (n : Person) RETURN count(n)` will be significantly more efficient, both in terms of memory consumption and memory utilization.

## Parameterized openCypher queries not supported for algorithms
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Neptune Analytics supports [parameterized openCypher queries](https://docs.aws.amazon.com/neptune/latest/userguide/opencypher-parameterized-queries.html) with the limitation that parameters are not allowed inside algorithms.

For instance, a query such as `CALL neptune.algo.degree($id)` where `$id` is passed in as a parameter is currently not supported.

## Size limits on properties, labels and strings
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 The maximum length of the strings supported is 1,048,062 bytes. The limit would be lower for strings with unicode characters since some unicode characters are represented using multiple bytes. 

## Labelless vertices with only embeddings are not supported
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 Neptune Analytics supports labelless vertices, which are vertices without vertex labels. The labelless vertices may or may not have vertex properties. However, there is a limitation that labelless vertices with only vector embeddings are not supported. They must either have a vertex label or a vertex property.