Hi Jeff, On Thu, Mar 18, 2010 at 4:49 PM, Jeff Schnitzer <[email protected]> wrote:
> On Thu, Mar 18, 2010 at 9:32 AM, Nick Johnson (Google) > <[email protected]> wrote: > > Hi Jeff, > > Unindexed properties are excluded from all indexing, not just from > indexing > > by the built-in indexes. > > -Nick Johnson > > Ah ha. The next question then is - why? > > This current arrangement has some particularly nasty consequences: > > 1) If you want a custom index across 3 properties, you are now forced > to maintain seven indexes total - the three single-property ASC > indexes, the three single-property DESC indexes, and the actual custom > index. > None of the built in indexes require 'maintenance'. There's also only a single desc, and a single asc index for all properties. > > 2) If you want to create a custom index across a property that does > not currently have a single-property index, you must manually go > through and reprocess you entire dataset. The automatic index > building isn't automatic. > If you mean that you want to index a field that was previously listed as an unindexed field then yes, you do. -Nick Johnson > On the other hand, there doesn't seem to be much benefit to the > current approach. It does provide the ability to make rdbms-like > partial indexes in custom indexes as well as single-property indexes, > but it seems like any minor gain is going to be overshadowed by the > fact that you're now maintaining quite a large number of additional > indexes. > > Furthermore, the only way to access this partial index functionality > is with the low-level API. At the higher level APIs, you can only > flag a property as unindexed or not. If the user wants a property to > be excluded from a custom index... they can easily remove it from the > datastore-indexes.xml/yaml. So this default doesn't buy you anything > and actually costs you a lot of flexibility and extra index overhead. > > Unless I'm missing something? > > Jeff > > -- > You received this message because you are subscribed to the Google Groups > "Google App Engine" group. > To post to this group, send email to [email protected]. > To unsubscribe from this group, send email to > [email protected]<google-appengine%[email protected]> > . > For more options, visit this group at > http://groups.google.com/group/google-appengine?hl=en. > > -- Nick Johnson, Developer Programs Engineer, App Engine Google Ireland Ltd. :: Registered in Dublin, Ireland, Registration Number: 368047 -- You received this message because you are subscribed to the Google Groups "Google App Engine" 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?hl=en.
