1. A method comprising, by one or more computing devices: receiving, from a client system of a first user, a search query input comprising a character string having a first number of characters; searching, by the one or more computing devices, one or more indexes of one or more verticals, respectively, to identify terms corresponding to the search query input, each index comprising terms associated with objects of a particular object-type of a plurality of object-types indexed by the one or more verticals, wherein: if the first number is less than or equal to a first threshold number, then searching one or more first indexes, wherein each first index is related to objects of a first object-type; and if the first number is greater than the first threshold number, then searching the one or more first indexes and one or more second indexes, wherein each second index is related to objects of a second object-type different than the first object-type; and sending, to the client system of the first user, instructions for presenting one or more suggested queries, each suggested query comprising the character string of the search query input and one or more of the identified terms.