Extract Operator

One or more computer-readable non-transitory storage media embodying software that is operable when executed to:

• receive, from a client system of a first user of an online social network, a search query requesting one or more objects of a first object type, the search query comprising an inner query requesting one or more objects of a second object type;
• identify the one or more objects of the second object type requested by the inner query using an inverted index of a data store corresponding to the second object type;
• identify the one or more objects of the first object type requested by the search query using one or more of the identified objects of the second object type and a forward index of the data store corresponding to the second object type;
• and
• send, to the client system of the first user, one or more search results responsive to the search query, each search result corresponding to an identified object of the first object type.

A system comprising:

• one or more processors;
• and a non-transitory memory coupled to the processors comprising instructions executable by the processors, the processors operable when executing the instructions to:
• receive, from a client system of a first user of an online social network, a search query requesting one or more objects of a first object type, the search query comprising an inner query requesting one or more objects of a second object type;
• identify the one or more objects of the second object type requested by the inner query using an inverted index of a data store corresponding to the second object type;
• identify the one or more objects of the first object type requested by the search query using one or more of the identified objects of the second object type and a forward index of the data store corresponding to the second object type;
• and
• send, to the client system of the first user, one or more search results responsive to the search query, each search result corresponding to an identified object of the first object type.