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Dynamic System Tables › Using SQC Table to Cancel SQL Requests › Processing Details

Processing Details

When a delete is processed, the rows in the SQC Dynamic System Table are not actually deleted. Instead, the following steps occur:

  1. A flag is set for each corresponding transaction to be aborted when the next row is read by either SQL or Compound Boolean Selection (CBS).
  2. When the request is aborted, SQLCODE -128, LUW ABORTED, is generated.
  3. The application is then given the opportunity to issue a commit or rollback.
  4. Until the transaction is ended, all subsequent requests to read rows are also aborted with the SQLCODE -128, but subsequent transactions initiated by the application are not affected.

Note: Once the abort flag has been set, there is no way to reset it until the transaction ends. Neither is there a way to report on which transactions have the abort flag set but have not yet ended.