Auto Encoding recommends string column encodings. Using the right string column encodings can reduce the amount of memory required on HeatWave nodes and improve query performance. HeatWave supports two string column encoding types: variable-length and dictionary. HeatWave applies variable-length encoding to string columns by default when data is loaded. Auto Encoding generates string column encoding recommendations by analyzing column data, HeatWave query history, query performance data, and available memory on the MySQL node. For more information about string column encoding, see Section 2.7.1, “Encoding String Columns”.