Question

I’m building a GAE app that has objects with a lot of boolean properties. I want to be able to search through those properties making a query like (in psuedo-sql) “get items where X1=True, X2=False, X3=False and let X4 through X7 be either true or false”.

I have a model similar to the one shown below:

class JobModel(BaseModel):
  job_name      = db.StringProperty();
  part_time     = db.BooleanProperty();
  has_401k      = db.BooleanProperty();
  has_health_in = db.BooleanProperty();
  has_childcare = db.BooleanProperty();
  has_edu_reim  = db.BooleanProperty();

The problem is that GAE requires an index for every possible way of searching these booleans. So if you have 5 boolean properties you will need 32 different indexes. If you have 20 boolean properties (in my actual case) you need over a million indexes!

There must be a better way to setup this datastore schema, right?

Answer 1

This may be a good opportunity for a StringListProperty.

Set membership is a strength of the ListProperty.

You would need to provide a way to update and marshal the list but it could be efficient for your needs.

db.StringListProperty

has = ['401k:T', 'health_in:F', 'has_childcare:T']

GQL Where Clause

"WHERE has = '401k:T' and has = 'health_in:F'"

ListProperties require some effort to understand their strengths and application.

GAE datastore list property serialization