5.4.5 The rpd_preload_stats Table

The rpd_preload_stats table stores column level statistics collected from InnoDB tables. The statistics are used to estimate the number of HeatWave nodes required for a given dataset prior to loading the tables into the HeatWave Cluster.

The rpd_preload_stats table has these columns:

  • TABLE_SCHEMA

    The schema name.

  • TABLE_NAME

    The table name.

  • COLUMN_NAME

    The column name.

  • AVG_BYTE_WIDTH_INC_NULL

    The average byte width of the column. The average value includes NULL values.

The rpd_preload_stats table has the following characteristics:

  • It is read-only. DDL, including TRUNCATE TABLE, is not permitted.

  • It is truncated before new statistics are added.

  • It cannot be dropped, truncated, or modified by DML statements directly.

  • Statistics are not persisted when the server is shut down.

  • It has a limit of 65536 rows.

  • Statistics are approximate, based on an adaptive sample scan.

  • Statistics are deterministic, provided that the data does not change.