# AWS Lambda function and parameter reference
Following is the reference for the functions and parameters to use for invoking Lambda with RDS for PostgreSQL.
**Topics**
+ [aws\$1lambda.invoke](#aws_lambda.invoke)
+ [aws\$1commons.create\$1lambda\$1function\$1arn](#aws_commons.create_lambda_function_arn)
+ [aws\$1lambda parameters](#aws_lambda.parameters)
## aws\$1lambda.invoke
Runs a Lambda function for an RDS for PostgreSQL DB instance.
For more details about invoking Lambda functions, see also [Invoke](https://docs.aws.amazon.com/lambda/latest/dg/API_Invoke.html) in the *AWS Lambda Developer Guide.*
**Syntax**
------
#### [ JSON ]
```
aws_lambda.invoke(
IN function_name TEXT,
IN payload JSON,
IN region TEXT DEFAULT NULL,
IN invocation_type TEXT DEFAULT 'RequestResponse',
IN log_type TEXT DEFAULT 'None',
IN context JSON DEFAULT NULL,
IN qualifier VARCHAR(128) DEFAULT NULL,
OUT status_code INT,
OUT payload JSON,
OUT executed_version TEXT,
OUT log_result TEXT)
```
```
aws_lambda.invoke(
IN function_name aws_commons._lambda_function_arn_1,
IN payload JSON,
IN invocation_type TEXT DEFAULT 'RequestResponse',
IN log_type TEXT DEFAULT 'None',
IN context JSON DEFAULT NULL,
IN qualifier VARCHAR(128) DEFAULT NULL,
OUT status_code INT,
OUT payload JSON,
OUT executed_version TEXT,
OUT log_result TEXT)
```
------
#### [ JSONB ]
```
aws_lambda.invoke(
IN function_name TEXT,
IN payload JSONB,
IN region TEXT DEFAULT NULL,
IN invocation_type TEXT DEFAULT 'RequestResponse',
IN log_type TEXT DEFAULT 'None',
IN context JSONB DEFAULT NULL,
IN qualifier VARCHAR(128) DEFAULT NULL,
OUT status_code INT,
OUT payload JSONB,
OUT executed_version TEXT,
OUT log_result TEXT)
```
```
aws_lambda.invoke(
IN function_name aws_commons._lambda_function_arn_1,
IN payload JSONB,
IN invocation_type TEXT DEFAULT 'RequestResponse',
IN log_type TEXT DEFAULT 'None',
IN context JSONB DEFAULT NULL,
IN qualifier VARCHAR(128) DEFAULT NULL,
OUT status_code INT,
OUT payload JSONB,
OUT executed_version TEXT,
OUT log_result TEXT
)
```
------Input parameters
**function\$1name**
The identifying name of the Lambda function. The value can be the function name, an ARN, or a partial ARN. For a listing of possible formats, see [ Lambda function name formats](https://docs.aws.amazon.com/lambda/latest/dg/API_Invoke.html#API_Invoke_RequestParameters) in the *AWS Lambda Developer Guide.*
*payload*
The input for the Lambda function. The format can be JSON or JSONB. For more information, see [JSON Types](https://www.postgresql.org/docs/current/datatype-json.html) in the PostgreSQL documentation.
*region*
(Optional) The Lambda Region for the function. By default, RDS resolves the AWS Region from the full ARN in the `function_name` or it uses the RDS for PostgreSQL DB instance Region. If this Region value conflicts with the one provided in the `function_name` ARN, an error is raised.
*invocation\$1type*
The invocation type of the Lambda function. The value is case-sensitive. Possible values include the following:
+ `RequestResponse` – The default. This type of invocation for a Lambda function is synchronous and returns a response payload in the result. Use the `RequestResponse` invocation type when your workflow depends on receiving the Lambda function result immediately.
+ `Event` – This type of invocation for a Lambda function is asynchronous and returns immediately without a returned payload. Use the `Event` invocation type when you don't need results of the Lambda function before your workflow moves on.
+ `DryRun` – This type of invocation tests access without running the Lambda function.
*log\$1type*
The type of Lambda log to return in the `log_result` output parameter. The value is case-sensitive. Possible values include the following:
+ Tail – The returned `log_result` output parameter will include the last 4 KB of the execution log.
+ None – No Lambda log information is returned.
*context*
Client context in JSON or JSONB format. Fields to use include than `custom` and `env`.
*qualifier*
A qualifier that identifies a Lambda function's version to be invoked. If this value conflicts with one provided in the `function_name` ARN, an error is raised.Output parameters
*status\$1code*
An HTTP status response code. For more information, see [Lambda Invoke response elements](https://docs.aws.amazon.com/lambda/latest/dg/API_Invoke.html#API_Invoke_ResponseElements) in the *AWS Lambda Developer Guide.*
*payload*
The information returned from the Lambda function that ran. The format is in JSON or JSONB.
*executed\$1version*
The version of the Lambda function that ran.
*log\$1result*
The execution log information returned if the `log_type` value is `Tail` when the Lambda function was invoked. The result contains the last 4 KB of the execution log encoded in Base64.
## aws\$1commons.create\$1lambda\$1function\$1arn
Creates an `aws_commons._lambda_function_arn_1` structure to hold Lambda function name information. You can use the results of the `aws_commons.create_lambda_function_arn` function in the `function_name` parameter of the aws\$1lambda.invoke [aws\$1lambda.invoke](#aws_lambda.invoke) function.
**Syntax**
```
aws_commons.create_lambda_function_arn(
function_name TEXT,
region TEXT DEFAULT NULL
)
RETURNS aws_commons._lambda_function_arn_1
```Input parameters
*function\$1name*
A required text string containing the Lambda function name. The value can be a function name, a partial ARN, or a full ARN.
*region*
An optional text string containing the AWS Region that the Lambda function is in. For a listing of Region names and associated values, see [Regions, Availability Zones, and Local Zones](Concepts.RegionsAndAvailabilityZones.md).
## aws\$1lambda parameters
In this table, you can find parameters associated with the `aws_lambda` function.
| Parameter | Description |
| --- | --- |
| `aws_lambda.connect_timeout_ms` | This is a dynamic parameter and it sets the maximum wait time while connecting to AWS Lambda. The default values is `1000`. Allowed values for this parameter are 1 - 900000. |
| `aws_lambda.request_timeout_ms` | This is a dynamic parameter and it sets the maximum wait time while waiting for response from AWS Lambda. The default values is `3000`. Allowed values for this parameter are 1 - 900000. |
| `aws_lambda.endpoint_override` | Specifies the endpoint that can be used to connect to AWS Lambda. An empty string selects the default AWS Lambda endpoint for the region. You must restart the database for this static parameter change to take effect. |