Docs > Datastore API > Keys and Entity Groups の
Entity Groups, Ancestors and Paths の以下の部分は重要そうです。
When the application creates an entity, it can assign another entity as the parent of the new entity. Assigning a parent to a new entity puts the new entity in the same entity group as the parent entity.
An entity without a parent is a root entity. An entity that is a parent for another entity can also have a parent. A chain of parent entities from an entity up to the root is the path for the entity, and members of the path are the entity's ancestors. The parent of an entity is defined when the entity is created, and cannot be changed later.
・データモデルについてはgoogle-appengine groupでも議論が行われている １：１，１：ｎ
Small tutorial on ER-modeling with GAE - 6 new
http://groups.google.com/group
I wrote a small tutorial about ER-modeling with Google App Engine:
http://daily.profeth.de/2008/04/er-modeling-with-google-app-engine.html
・fulltext search機能の現状について Indexing Large Chunks of Text for Search
There's no ranking, which is a killer drawback. （致命的欠点）
no exact phrase match, substring match, boolean operators,
support for stop words (common words that are not indexed) is currently limited to English.
・検索結果の件数については
Docs > Datastore API > GqlQuery を参考
* bind()
* get()
* fetch()
* count()
greetings = Greeting.all().order('-date')で件数をカウントすることができました。
row_cnt = greetings.count()
