1. A system comprising: a processor and executable instructions accessible on a computer-readable medium that, when executed, cause the processor to perform operations comprising: receive, from a first user, a search query to search for document information in a database, the database including an index data structure; determine that terms of the search query are in accordance with dictionary information that corresponds to the first user, the dictionary information for the first user including a first list of compatible query operators; apply the search query to the index data structure in the database to identify the document information; and send an electronic interface to the first user, the electronic interface including the document information.
1. A system comprising: a processor and executable instructions accessible on a computer-readable medium that, when executed, cause the processor to perform operations comprising: receive, from a first user, a search query to search for document information in a database, the database including an index data structure; determine that terms of the search query are in accordance with dictionary information that corresponds to the first user, the dictionary information for the first user including a first list of compatible query operators; apply the search query to the index data structure in the database to identify the document information; and send an electronic interface to the first user, the electronic interface including the document information. 10. The system of claim 1 , wherein the search query is arranged as an expression tree that includes at least one child node coupled to at least one parent node and wherein data included in the at least one child node is an input to an operator included in the at least one parent node.