Question

我正在研究一个GAE/2008/4项目,该项目有物品和交易。

首先,我们尝试使用一种有参考财产的物品和交易,但这使问题变得十分复杂。

因此,我们转而采用一刀式的版本,将交易数据直接储存在该项目内,结果造成许多特性没有被使用,因为并非所有项目都涉及交易。

我期望它加快步伐,但这是这样做的最佳方式吗?

了解:

we expect to have lots of transactions and many more items.
we need to check the transaction status (actually stored in the item s status).
there is only one transaction possible per item but there are many different kind of transactions.

是否有更好的解决办法?

EDIT:

问题在于,我主要询问使用交易属性的物品,但只有2个,即规定最多一次,而且经常更新交易。

实际上,我有这样的东西:

MyItem(db.Model):

owner = db.ReferenceProperty(MyUser)  
descr = db.StringProperty()  

status = db.IntegerProperty()  # contains item status / transaction status

tx_actor = db.emailProperty()
tx_token = db.StringProperty()
latest_tx_date = db.DateTimeProperty()

Answer 1

由于它绘制了1至1幅地图,它oil倒了你需要询问的项目或交易的许多属性——这些属性需要加以指数化,以及你经常写出贵件或交易。

An example where it s fine to merge them: - You rarely write your merged item/transaction object. - You query on a small set of attributes, many of the attributes do not need to be indexed. - When you do queries, you usually want both the item AND the transaction.

An example where it s a bad idea to merge them: - Your item has many indexed attributes, but your transaction has very few. But you need to update your transaction frequently. In this case you d be better off keeping them separate, because every time you write the transaction, you incur all the write costs of updating the indices for the item.

另一种选择是,如果DON T需要询问交易,将交易作为JSON编码储存,那么你就不必界定所有属性。你们也可以使用“扩大”类别。

为了得到更好的答案,你最好不要列举贵项目/交易所看的事例,以及你希望处理的询问类型。

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