David, thank you very much for your reply. It's great to see that all questions are answered on this list.
> > I understand that the mapper implementation is not optimized. > > This is not correct. The Mapper stuff is fairly well optimized. It, in > general, executes 6 times faster than ActiveRecord, running the same queries > (thus destroying any of Rail's claims about the time being spent in the > database.) Good to know. Now I know that the problem was the amount of queries, not Lift's handling of SQL. > I generally write hand-code that pre-fetches. This generally results in > significant performance improvements (and 2 or 3 queries per page-load.) Thanks for the example. The reason I asked was, that I have two mappers, Blog and BlogEntry. BlogEntry links to the Blog with an owner field. If I have lots of BlogEntries and ask every item for the blog it creates a lot of SQL queries (one for each entry), even if they link to the same blog. So I thought it would be great to have something like caching or prefetching build-in so a second query to the same blog is not necessary any more. Your example helps to speed this up, but usually I want to work with the objects itself. I've build a simple CachedMetaMapper trait for my classes, which caches findAll and find(Any). Not optimal, but some improvement. > > - What is a good way to cache queries generated by MetaMapper.find() > > and findAll() ? > > I leave this to the RDBMS. If you're doing a read-heavy app (like a CMS > system), I'd manually build a cache in memory... as long as I was sure there > were no external apps that could update the RDBMS out from under me. That's what I finally did. Together with manual tuning (e.g. with a prefetched map) it works very well. Thank you for your patience and help :) Joachim --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Lift" group. To post to this group, send email to liftweb@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/liftweb?hl=en -~----------~----~----~----~------~----~------~--~---
