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