Exam Professional Data Engineer topic 1 question 44 discussion

Correct answer is A Read in reference : https://cloud.google.com/datastore/docs/concepts/indexes#index_limits n this case, you can circumvent the exploding index by manually configuring an index in your index configuration file: indexes: - kind: Task properties: - name: tags - name: created - kind: Task properties: - name: collaborators - name: created This reduces the number of entries needed to only (|tags| * |created| + |collaborators| * |created|), or 6 entries instead of 9

you can circumvent the exploding index by manually configuring an index in your index configuration file: https://cloud.google.com/datastore/docs/concepts/indexes#index_limits

Tempted to go with D as the syntax in Option A seems incorrect. D is still a possible answer because one of the ways to get rid of index errors is to remove the entities that are causing the index to explode. In this case its date_released and hence D appears right to me

Option B & D reject because mention date_publised in question date_released is column Option C also not correct, I would go with option A.

Correct Answer D: This is the way the DB is typically queried: - movies with actor=<actorname> ordered by date_released - movies with tag=Comedy ordered by date_released so it seems that we need indices in actor,tag and date_released for sorting. ❌ A: this would be the correct answer, however, the format is incorrect, the correct format would be '- name: date_released' correctly indented. ❌ B: This seems to be unnecessary, since typically actor and tag are not queried together. also, there is a clear indentation issue ❌ C: We don't want to ignore actor and tag, we need those indices. ✅ D: If we leave datastore to automatically create the indices and if we specify that the 'date_released' property needs to be excluded from indices, then we would have less indices (but maybe slower queries when ordering them, but hey, how many 'comedies' there could be in the world)

What do people think about C? The question is asking how to avoid a combinatorial explosion in the number of indexes. It says "You have entities with multiple properties, some of which can take on multiple values". Put this with the below text from the documentation for Datastore indexes, it seems they're looking for "exclude the properties that will cause combinatorial explosion" which would be C. "The situation becomes worse in the case of entities with multiple properties, each of which can take on multiple values. To accommodate such an entity, the index must include an entry for every possible combination of property values. Custom indexes that refer to multiple properties, each with multiple values, can "explode" combinatorially, requiring large numbers of entries for an entity with only a relatively small number of possible property values."[1] [1] https://cloud.google.com/datastore/docs/concepts/indexes#index_limits

B. is correct To avoid combinatoric explosion of indexes. "Two queries of the same form but with different filter values use the same index." https://cloud.google.com/datastore/docs/concepts/indexes

A. Manually configure the index in your index config as follows: