Node name: XANDOR
Represents: The index over XML data ANDing of the results of multiple index scans, used for the evaluation of complex predicates from a single query.
If any of these conditions are not met the Index intersection operation will be used instead.
Rows RETURN ( 1) Cost I/O | 0.00915933 NLJOIN ( 2) 985.789 98.9779 /--+--\ 2.96215 0.00309213 FETCH XSCAN ( 3) ( 11) 340.113 217.976 19 27 /---+---\ 2.96215 210000 RIDSCN TABLE: DB2XML ( 4) TPCHX 332.008 18 | 2.96215 SORT ( 5) 331.957 18 | 2.96215 XANDOR ( 6) 331.784 18 +----------------+--------+-------+----------------+ 355.62 6996.81 105000 105000 XISCAN XISCAN XISCAN XISCAN ( 7) ( 8) ( 9) ( 10) 165.892 3017.54 1.6473e+06 851554 9 81 27768 14898 | | | | 210000 210000 210000 210000 XMLIN: DB2XML XMLIN: DB2XML XMLIN: DB2XML XMLIN: DB2XML TPCHX_IDX TPCHX_IDX TPCHX_IDX TPCHX_IDX
Each XISCAN node will perform an index scan and feed the XANDOR node with the XML node IDs that qualify. The XANDOR node will apply the AND and OR predicates and return the XML nodes that satisfy the XML pattern for the query.