Hello Zotov,
Somehow the equivalence d2.basedon=d1.id is not used in the slow query,
probably because the equivalence constant value would be used inside a
not-base expression (the OR). You can see that the equivalence values
*are* used by changing the or to an and and compare both queries. Th
I have a query:
SELECT d1.ID, d2.ID
FROM DocPrimary d1
JOIN DocPrimary d2 ON d2.BasedOn=d1.ID
WHERE (d1.ID=234409763) or (d2.ID=234409763)
i think what QO(Query Optimizer) can make it faster (now it seq scan and on
million records works 7 sec)
SELECT d1.ID, d2.ID
FROM DocPrimary d1
J
