In a DB2 Explain Plan, what does
TBSCAN GENROW (line 5 below) mean?
SELECT STATEMENT ( Estimated Costs = 1.811E+03 [timerons] ) 1 RETURN 2 NLJOIN 3 [O] TBSCAN 4 SORT 5 TBSCAN GENROW 6 [I] FETCH EKKO 7 IXSCAN EKKO~1 #key columns: 2
The IBM docs say
"A built-in function that generates a table of rows, using no input from tables, indexes, or operators"
What does that mean from a performance perspective?
Also, this is in an SAP system if that matters.