+1 big-time on this. With the restriction that every index'able property must be indexed at put-time when put into the datastore (using setProperty as opposed to setUnindexedProperty), it has 2 MAJOR disadvantages with far-reaching repercussions:
- you cannot index entities after they have been put (even with a custom index). You will have to re-write the entity to index it. - Each put is 4X more expensive in latency/clock-time (potentially), CPU-cost and storage. This seems un-necessary, especially if a single custom index will suffice all your querying needs. I was really hoping to use custom indexes to buy major performance savings (in latency, CPU-cost and storage), and also be able to re- index every entity after the fact. But this restriction is heavy (preventing direct solution to a problem everyone may end up facing), and very expensive (costing us big-time). Can one of the google guys respond to this, before we file a bug? Thanks. On Mar 16, 2:07 pm, Jeff Schnitzer <[email protected]> wrote: > On Mon, Mar 15, 2010 at 11:04 PM, John Patterson <[email protected]> > wrote: > > > On 16 Mar 2010, at 12:25, Jeff Schnitzer wrote: > > >> I'm puzzled by the behavior of custom indexes. I have a simple test > >> case below, a simple equality filter on one property combined with a > >> descending sort on another property. If I set the properties with > >> setUnindexedProperty(), the query fails to find the result. If I set > >> the properties with setProperty(), it does. > > > I also wondered why - I assume that the custom index build reads the single > > property indexes directly which must be more efficient than reading the > > Entities "table". > > I guess that is possible, but seems like a poor design decision. It > makes adding custom indexes after-the-fact really, really painful. > > Can someone official chime in on this? Is it intended behavior, or > should we file an issue against it? The documentation doesn't say > much on the subject, and all the conceptual explanation of queries > suggests that these extra single-property indexes will be unused. > > Jeff -- You received this message because you are subscribed to the Google Groups "Google App Engine for Java" 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/google-appengine-java?hl=en.
