Performance relation of xquery with Schema

Hi
Some relation exists that improve the searches in xml (xquery) utilizing
schema colletion or they are independent?
Thank
Cristián
Hello sqlextreme,

> Hi
> Some relation exists that improve the searches in xml (xquery)
> utilizing
> schema colletion or they are independent?
There's three performance related benefits of using schema-bound XML.
a.) it prevents the query processor from doing an impossible yet potentially
expensive query. The query is checked against schema first to see if even
possible.
b.) The query processor better understands the structure of the underlying
XML which may result in more effecient query plans.
c.) Since the schema can providing typing information, ranging and comparsion
operations can be more efficient.
Does it make a big difference? It can, but in general practice, I've seldom
seen it amount to more than a 5% difference in actual query costs.
Thanks!
Kent Tegels
DevelopMentor
http://staff.develop.com/ktegels/
|||Hi Kent
Thank you so much for your time, this helps me a lot.
Cristián
"Kent Tegels" wrote:

> Hello sqlextreme,
>
> There's three performance related benefits of using schema-bound XML.
> a.) it prevents the query processor from doing an impossible yet potentially
> expensive query. The query is checked against schema first to see if even
> possible.
> b.) The query processor better understands the structure of the underlying
> XML which may result in more effecient query plans.
> c.) Since the schema can providing typing information, ranging and comparsion
> operations can be more efficient.
> Does it make a big difference? It can, but in general practice, I've seldom
> seen it amount to more than a 5% difference in actual query costs.
> Thanks!
> Kent Tegels
> DevelopMentor
> http://staff.develop.com/ktegels/
>
>