Here's a link:
http://groups.google.com/group/google-appengine/browse_thread/thread/2f6aa695a80fd5de
Jeff
On Thu, Mar 18, 2010 at 9:22 AM, Tristan <tristan.slomin...@gmail.com> wrote:
> Jeff,
>
> Sounds to me like you're correct in the "not only don't set single-
> property indexes, but also don't include the property in any custom
> indexes" interpretation of setUnindexedProperty. Can you post the link
> to the continuation post? I'm curious what Googlers have to say about
> it.
>
> Tristan
>
>
>
> On Mar 18, 11:13 am, Jeff Schnitzer <j...@infohazard.org> wrote:
>> This doesn't make sense to me.
>>
>> Every scrap of documentation I've found says that GAE queries only
>> follow a single index (the one exception being zigzag merges, which
>> don't apply here). This means that to answer my query.filter(foo,
>> "fooValue1").sort("-bar"), there must be an index that contains the
>> foo and bar data sorted appropriately, no? Ie:
>>
>> /Thing/foo:fooValue1/bar:bar9/[thekeyvalue]
>> /Thing/foo:fooValue1/bar:bar8/[thekeyvalue]
>> /Thing/foo:fooValue1/bar:bar7/[thekeyvalue]
>> /Thing/foo:fooValue2/bar:bar8/[thekeyvalue]
>> /Thing/foo:fooValue2/bar:bar7/[thekeyvalue]
>>
>> To satisfy this query, GAE should start following this custom index
>> and that's pretty much it. There's no reason for it to touch the
>> single-property indexes (foo ASC, foo DESC, bar ASC, and bar DESC).
>>
>> ...and in my test, if I remove the custom index from
>> datastore-indexes.xml, it doesn't work. But also if I use
>> setUnindexedProperty, it doesn't work.
>>
>> It's like setUnindexedProperty is being interpreted as "not only don't
>> set single-property indexes, but also don't include the property in
>> any custom indexes". This is counterintuitive - if I wanted the index
>> not to be built, I can just remove the index.
>>
>> I realize now that perhaps I posted this to the wrong mailing list.
>> The guys who created the I/O videos about the datastore seem to be
>> python fans, so I'll retry my original post on the google-appengine
>> list.
>>
>> Jeff
>>
>>
>>
>> On Thu, Mar 18, 2010 at 8:00 AM, Tristan <tristan.slomin...@gmail.com> wrote:
>> > Not official but been doing this for a while.
>>
>> > Your custom index is most likely build from the query. So, when you
>> > do
>>
>> > Query query = new Query("Thing");
>> > query.addFilter("foo", FilterOperator.EQUAL, "fooValue");
>> > query.addSort("bar", SortDirection.DESCENDING);
>>
>> > That is what builds your custom index.
>>
>> > However, when you setUnindexedProperty here
>>
>> > Entity ent = new Entity("Thing");
>> > ent.setUnindexedProperty("foo", "fooValue");
>> > ent.setUnindexedProperty("bar", 123L);
>>
>> > You are not generating any index entries.
>>
>> > So the issue isn't that "adding custom indexes after-the-fact [is]
>> > really, really painful" but that you are not generating any indexes
>> > for the datastore to run the queries against when you use
>> > setUnindexedProperty(). In other words, when you execute a query, it
>> > checks the index to give you results. But you marked your data as
>> > "don't index me," so there is nothing for query to work with, as far
>> > as it is concerned, there's nothing in the datastore.
>>
>> > Cheers!
>>
>> > On Mar 16, 4:07 pm, Jeff Schnitzer <j...@infohazard.org> wrote:
>> >> On Mon, Mar 15, 2010 at 11:04 PM, John Patterson <jdpatter...@gmail.com>
>> >> 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
>>
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