But OrderBy runs on the server (SELECT ... ORDER BY ...), so it has nothing to do with hashing algorithms...
RP On Friday, October 10, 2014 5:33:57 AM UTC+1, Darren Kopp wrote: > > I would guess that the performance you see on your machine is the same as > on Azure, but you're likely hitting your cpu limits. I'm not sure ordering > would have any issue on hydration, unless perhaps you have a poor hash code > algorithm and perhaps were hitting worst case scenarios on hash tables, but > that also seems pretty suspect. Do you have any .net profiling data > comparing the two scenarios you outlined? > > On Wednesday, October 8, 2014 7:14:11 AM UTC-6, Lauri Kotilainen wrote: >> >> Hi, >> >> I encountered a really weird situation today. I've got a NHLinq query >> that does an OrderBy, then adds a bunch of Fetches and finally ToLists the >> whole thing. The query returns about 700 root entities from a total of >> about 2000 rows. It's a fairly heavy query, and on my development machine, >> it takes between 1 and 3 seconds to finish hydrating the entities. >> >> The weird part starts, unfortunately, with a production database. The DB >> is running on Azure SQL Databases. And on the production db, the query >> takes anywhere between 15 and 20 seconds to execute. However, if I export >> the production database to a copy and run the query against the copy, we're >> back to between 1 and 3 seconds. >> >> OK, I think to myself, maybe the import/export does something to >> rearrange the data. Except... according to NHProf, the query itself takes >> under 200ms to execute, and the rest of the time is spent in hydration. >> I've confirmed this with SQL Server Management Studio -- the SQL query >> itself completes in under a second. >> >> And here's where it gets *really* weird: if I remove the OrderBy clause >> from the NHLinq query, we're back to 1-3 second execution times. >> >> I guess my question is basically: what can the OrderBy call possibly do >> that would make hydration an order of magnitude slower in some cases? >> >> -Lauri >> > -- You received this message because you are subscribed to the Google Groups "nhusers" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at http://groups.google.com/group/nhusers. For more options, visit https://groups.google.com/d/optout.
