# Configuring functions

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This page was generated from content adapted from the [AWS Developer Guide](https://github.com/awsdocs/aws-lambda-developer-guide.git)
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## Configuring function options

* **Note**\
  Configuring ephemeral storage past the default 512 MB allocated incurs a cost. For more information, see [Lambda pricing](https://aws.amazon.com/lambda/pricing).
* **Note**\
  Compute Optimizer supports only functions that use x86\_64 architecture.

## Environment variables

* **Note**\
  To increase database security, we recommend that you use AWS Secrets Manager instead of environment variables to store database credentials. For more information, see [Configuring database access for a Lambda function](https://docs.aws.amazon.com/lambda/latest/dg/configuration-database.html).
* **Note**\
  In some cases, you may need to use the following format:
* **Note**\
  To increase database security, we recommend that you use AWS Secrets Manager instead of environment variables to store database credentials. For more information, see [Configuring database access for a Lambda function](https://docs.aws.amazon.com/lambda/latest/dg/configuration-database.html).

## Versions

* **Note**\
  Lambda doesn't create a new version if the code in the unpublished version is the same as the previous published version. You need to deploy code changes in $LATEST before you can create a new version.

## Creating layers

* **Note**\
  For Node.js runtimes, Lambda doesn't currently support ES module dependencies in layers.
* **Note**\
  Each time that you call `publish-layer-version`, you create a new version of the layer.