Effect of the dataskip feature on transactions

If you turn the dataskip feature on, a SELECT statement always executes. In addition, an INSERT statement always succeeds if the table is fragmented by round-robin and at least one fragment is online. However, the database server does not complete operations that write to the database if a possibility exists that such operations might compromise the integrity of the database. The following operations fail:
  • All UPDATE and DELETE operations where the database server cannot eliminate the down fragments

    If the database server can eliminate the down fragments, the update or delete is successful, but this outcome is independent of the DATASKIP setting.

  • An INSERT operation for a table fragmented according to an expression-based distribution scheme where the appropriate fragment is down
  • Any operation that involves referential constraint checking if the constraint involves data in a down fragment

    For example, if an application deletes a row that has child rows, the child rows must also be available for deletion.

  • Any operation that affects an index value (for example, updates to a column that is indexed) where the index in question is located in a down chunk

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