Platform-independent Runtime Issues¶

Data Type Return Values Do Not Match Expected Return Values¶

When passing arguments to or from an external function, ensure that the data types are appropriate. If the value sent can’t fit into the data type being received, the value might be truncated or corrupted in some other way.

For more details, see Ensure that arguments to the external function correspond to arguments parsed by the remote service.

Error: Row numbers out of order¶

Possible Causes:

The row numbers you return within each batch should be monotonically ascending integers starting at 0. The input row numbers must also follow this rule, and each output row should match the corresponding input row. For example, the output in output row 0 should correspond to the input in input row 0.

Possible Solutions:

Ensure that the row numbers you return are the same as the row numbers you received, and that each output value uses the row number of the corresponding input. If this doesn’t work, then the input row numbers may not be correct or you did not return the rows in the correct order.

Next, ensure that the output row numbers start from 0, increase by 1, and are in order.

For more information about data input and output formats, see When Snowflake sends data to a remote service, or receives data from a remote.

Error: “Error parsing JSON: Invalid response”¶

Possible Causes:

The most likely cause is that the JSON returned by the remote service (e.g. AWS Lambda function) is not constructed correctly.

Possible Solutions:

Ensure that the external function returns an array of arrays, with one inner array returned for each input row received. Review the description of the output format at Data format received by Snowflake.

Error: Format of the returned value is not JSON¶

Possible Causes:

Your return value includes double quotes inside the value.

Possible Solutions:

Although JSON strings are delimited by double quotes, the string itself should not start and end with a quotation mark in most cases. If the embedded double quotes are incorrect, remove them.

Error: Function received the wrong number of rows¶

Possible Causes:

The remote service tried to return more or fewer rows than it received. Even though the function is nominally scalar, it might receive multiple rows in the body field of the event parameter, and should return exactly as many rows as it received.

Possible Solution(s):

Ensure that the remote service returns one row for each row that it receives.