(Glue-2002) Selective Deletion

Owned by SNP
Sept 17, 2019

Transaction:

/DVD/GL_SEL_DEL

This functionality enables you to delete data, which you have selected in Glue Data Browser through the transaction /DVD/GL_SEL_DEL. The procedure for selection of data is the same as described in (Glue-2002) Data Browser documentation.

Requirements

(Glue-2002) Data Browser


Soft selective deletion

Soft selective deletion is a functionality that is available for Hadoop storages which use Hive or Impala. The functionality is accessible through the transaction /DVD/GL_SEL_DEL. Data which should be deleted is selected the same way as in Data Browser, for more information see the (Glue-2002) Data Browser chapter.

An administrator should assign this transaction only to relevant users.

For Hive and Imala storages, you must specify a hint: "UseNativeQuery=1;" in storage settings.

Prerequisites for soft selective deletion

  • fields GLREQUEST (Request) and DVD_DELETION_INDICATOR (of type XFELD) are included in the table structure.

To execute soft selective deletion follow these steps:

  1. Go to /DVD/GL_SEL_DEL
  2. Enter a table name
  3. Enter deletion criteria in select-options
  4. Click Program > Soft Sel. Deletion
  5. Schedule the program to execute the Soft selective deletion

The deletion process can be monitored through the transaction SM37. Once the deletion ends successfully, the following can be observed on the particular table:

  • Program copied everything from the specified table that complies with select-options criteria under a new Glue Request.
  • Program also sets X in the field DVD_DELETION_INDICATOR.

The table content after specified select-options and executed soft deletion can look the following way:

We can see in the figure that the five entries with the Glue Request 71.983 were copied into the same table under the new Glue Request 71.988. These new entries also have the field 'DVD_DELETION_INDICATOR' set to 'X'. The "X" indicates that these entries were deleted in SAP. The request with the greater number (in this case Glue Request 71.988 ) contains the current information about the record.

Soft selective deletion doesn't manipulate data that is already in Hadoop - instead, it copies corresponding data with adjusted values GLREQUEST and DVD_DELETION_INDICATOR.

Hard selective deletion

Hard selective deletion is also available for Hadoop storages, which use SQL execution engines. Run the deletion with the same transaction /DVD/GL_SEL_DEL.

We recommend to use partitioning carefully, as it can improve performance. It is only necessary to access affected partitions.

Procedure to execute hard selective deletion is similar to soft selective deletion:

  1. Go to the transaction /DVD/GL_SEL_DEL
  2. Enter a table name
  3. Enter deletion criteria in select-options
  4. Click Program > Hard Sel. Deletion
  5. Schedule the program to execute the Hard selective deletion

The deletion process can be monitored through the transaction SM37. Once the deletion process ends successfully, the following can be observed in the table:

  • Program deleted everything from the specified table that complies with select-options criteria

The hard selective deletion manipulates with data that is present on Hadoop. It physically deletes entries that comply with the select-options. This process is irreversible, which means deleted data can't be recovered.

If you try to find the data the following message appears: