Poor performance with ISDESCENDANTNODE and OR

[Robert Haycock]

I have the following query using ISDESCENDANTNODE.

SELECT * FROM [nt:customNode] AS document

WHERE (

     ISDESCENDANTNODE(document,
'/ourRoot/4709617c-2b4a-4dbd-ab63-4a97ca66c5c2/2917bd05-74f7-43da-9506-3
0dd7631cafc')

     OR ISDESCENDANTNODE(document,
'/ourRoot/4709617c-2b4a-4dbd-ab63-4a97ca66c5c2/libraries/378d57e4-0036-4
537-bdd4-305e62aa9a67/1')

) 

AND (

    CONTAINS (document.name, 'bye') 

    OR CONTAINS (document.alias, 'Greeting')

) 

AND (

    documentType='FLOW' 

    OR documentType='LANGUAGE_OBJECT'

)

 

This takes 1394ms. When I comment out the first ISDESCENDANTNODE the
query takes 149ms. When I comment out the other, instead, the query
takes 172ms.

 

It seems to me that the original query shouldn't take almost 10 times as
long with both ISDESCENDANTNODE in.