8.1.2 The rpd_columns Table

The rpd_columns table provides column encoding information for columns of tables loaded in MySQL HeatWave.

The rpd_columns table has these columns:

• TABLE_ID

  A unique identifier for the table.

• COLUMN_ID

  A unique identifier for the table column.

• NDV

  The number of distinct values in the column.

• ENCODING

  The type of encoding used.

• DATA_PLACEMENT_INDEX

  The data placement key index ID associated with the column. Index value ranges from 1 to 16. For information about data placement key index values, see Section 5.8.2, “Data Placement Keys”. NULL indicates that the column is not defined as a data placement key. For a DATA_PLACEMENT_INDEX query that identifies columns with data placement keys, see Section 4.5, “Retrieve MySQL HeatWave Metadata”.

• DICT_SIZE_BYTES

  The dictionary size per column, in bytes.

The rpd_columns table is read-only.