How the express and deluxe modes work

A deluxe-mode load simulates an INSERT statement, except that the High-Performance Loader (HPL) allows the load to handle parallel data streams.

The sequence of events when you run an express-mode load is as follows:
  1. The onpload utility locks the table with a shared lock.

    Other users can read data in existing rows.

  2. The onpload utility creates new extents and fills them with the new rows. However, onpload does not update the database structures that track extents.

    The new extents are not visible to the user.

  3. At the end of the express load, onpload updates the internal structures of the database.
  4. The onpload utility sets the table to read-only.

    This setting occurs because in express mode onpload does not log data, and therefore, the table is in an unrecoverable state.

  5. The onpload utility unlocks the table and enables the constraints. The new rows become visible to the user for read only.
  6. The user performs a level-0 backup.
  7. Your database server sets the table to read/write.

If the load fails, onpload discards the extents and clears the internal information that says the table is unrecoverable.

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