Sunday, March 25, 2012

Does SQL 2005 take XML query time into acount?

if there's an [untyped] XField.Query() in a select, does SQL 2005 do
anything (internally) like an automatic sub-select if there's standard
fields to compare, saving the XML analysis for later, (to avoid uneccessary
calculations)?
Hello Jerry,
XML queries do cache their query plans, of course, like any other T-SQL query.
However, unindexed XML has to reconstruct the node table each time. That's
an expensive unit of work (usually), so the best thing you can (usually)
do is create an primary XML index over those instances. That "kind of" does
that you're looking for here.
Cheers,
Kent
|||> XML queries do cache their query plans, of course, like any other T-SQL
> query. However, unindexed XML has to reconstruct the node table each time.
> That's an expensive unit of work (usually), so the best thing you can
> (usually) do is create an primary XML index over those instances. That
> "kind of" does that you're looking for here.
Thanks for all, Kent ;)
sql

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