SQL Optimizer for DB2 ZOS 5.6 - User Guide

WFSCAN

Scan a work file.

A work file scan construct contains a WFSCAN node plus a work file node that is labeled WORKFILE.

WORKFILE

Denotes a work file or temporary table that DB2 generates.

DB2 labels a work file node with the word WORKFILE or with specific name. Sort (for JOIN, UNION, DISTINCT, GROUP BY, or ORDER BY operations) is the most common operation for generating work files.

XIXAND

Denotes operation where DB2 returns intersection of two sorted DOCID lists. Output includes only DOCIDs in both lists.

XIXOR

Denotes operation for XML data where DB2 returns the union of two sorted DOCID lists.

The output includes any DOCID that exists in at least one of the DOCID lists and removes duplicate DOCIDs.