Grooming tables

Deployment options: Netezza Performance Server for Cloud Pak for Data System Netezza Performance Server for Cloud Pak for Data

Groom Table processes and reorganizes the table records in each data slice in a series of steps. You can perform operations such as SELECT, UPDATE, DELETE, and INSERT while the online data grooming is taking place. The SELECT operations run in parallel with the groom operations. The INSERT, UPDATE, and DELETE operations run serially between the groom steps. For CBTs, the groom steps are longer than for non-CBT tables, so the INSERT, UPDATE, and DELETE operations might be pending for a longer time until the current step completes.

You can run the Groom Table operation to remove outdated and deleted records from tables while allowing access to all tables in the system.

About this task

Use the Groom Table functionality to reclaim disk space from deleted or outdated rows. You can also use this option to reorganize tables based on the clustered base table organizing keys or to migrate data from tables that have multiple stored versions.

Procedure

  1. Go to the Databases page.
  2. From the menu Objects, click on the Tables tab.
  3. Select the table you want to groom.
  4. In the table list, on the right side of the table, click on the drop down menu to expand it.
  5. Click Groom.
    Note:
    • To run the Groom Table operation, a user must have the GROOM object privilege.

      Grooming a table is done as a user, not an administrator, so to run Groom Table, you must have object privileges on that table as well.

    • You cannot run Groom Table inside a transaction block (begin or commit pair) or with a stored procedure.
    • When you specify organizing keys for an existing table to make it a CBT, the new organization can impact the compression size of the table. The new organization can create sequences of records that improve the overall compression benefit, or it can create sequences that do not compress so well. Following a groom operation, your table size can change compared with its previous organization.