" IMHO all these blanket statements simply show a narrow-minded approach to problem solving."
That sums it up perfectly. Know how the keys work, in NHibernate and on the DBMS, and make an informed choice. /G 2012/11/29 eag <[email protected]>: > Costa, Oskar is correct, using Identity columns does not perform, you are > better off using HiLo instead. You can easily prove it, if you have a long > transaction inserting many records in the table with an identity column, > even the INSERT commands are delayed to the end of the process, the Save > method in NHibernate returns the Id, that round trip is a killer. I have > seen processes were 10k records had to be created that were 10 times slower > using Identity instead of HiLo. Any communication between the AppServer and > Database server on the wire is expensive. > > As Oskar also mentions, batching can also improve performance, again, > because you might reduce the number of loops between AppServer and Database. > > > On Wednesday, November 28, 2012 8:39:28 PM UTC, costa wrote: >> >> @Gunnar Liljas: If you are joking ignore my message. If you are not joking >> this is the query that gets executed by NH when a new record is inserted in >> a table with an identity(1, 1) field: >> >> INSERT >> INTO >> [ >> dbo].[DataType] ( >> [Name] >> ) >> VALUES >> (@p0); >> select >> SCOPE_IDENTITY(); >> >> Note the select SCOPE_IDENTITY(); statement that's returning the new id in >> the same database call. Yes, it's an additional statement to get it but it's >> embedded in the same call and it should be very fast to get that value. >> >> As Sam pointed out, there is a price to pay for using GUIDS. I actually >> have done performance tests because I had an idiot at work that started to >> use them everywhere, and the performance starts to degrade pretty soon. They >> are also ugly when you write and run queries. >> >> >> >> > -- > You received this message because you are subscribed to the Google Groups > "nhusers" group. > To view this discussion on the web visit > https://groups.google.com/d/msg/nhusers/-/HoICwo6my_8J. > > To post to this group, send email to [email protected]. > To unsubscribe from this group, send email to > [email protected]. > For more options, visit this group at > http://groups.google.com/group/nhusers?hl=en. -- You received this message because you are subscribed to the Google Groups "nhusers" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/nhusers?hl=en.
