How DATASKIP affects table I/O

The DATASKIP configuration parameter allows you to specify which dbspaces, if any, queries can skip when those dbspaces are unavailable as the result of a disk failure. You can list specific dbspaces and turn data skipping on or off for all dbspaces.

When data skipping is enabled, the database server sets the sixth character in the SQLWARN array to W..
Warning: The database server cannot determine whether the results of a query are consistent when a dbspace is skipped. If the dbspace contains a table fragment, the user who executes the query must ensure that the rows within that fragment are not needed for an accurate query result. Turning DATASKIP on allows queries with incomplete data to return results that can be inconsistent with the actual state of the database. Without proper care, that data can yield incorrect or misleading query results.