conversionSpec

Specifies the timestamp format of the source data. Valid values are:

• epoch_sec - Unix epoch timestamp in seconds

• epoch_milli - Unix epoch timestamp in milliseconds

• iso - ISO 8601 formatted timestamp

Only specify ConversionSpec when using timestamp-based partition functions (year, month, day, or hour). Glue Zero-ETL uses this parameter to correctly transform source data into timestamp format before partitioning.

Do not use high-cardinality columns with the identity partition function. High-cardinality columns include:

• Primary keys

• Timestamp fields (such as LastModifiedTimestamp, CreatedDate)

• System-generated timestamps Using high-cardinality columns with identity partitioning creates many small partitions, which can significantly degrade ingestion performance.