13. A non-transitory computer readable medium having stored thereon computer executable instructions comprising: receiving, by an entity extraction computer, user input of search query parameters; extracting, by the entity extraction computer, a plurality of entities from the search query parameters by comparing each entity in the plurality of extracted entities with an entity co-occurrence in-memory database that includes a confidence score indicative of a degree of certainty of co-occurrence of an extracted entity with one or more related entities in an electronic data corpus, wherein the entity co-occurrence database further comprises one or more entries for the plurality of entities, and wherein each entry of the one or more entries for a given entity of the plurality of entities contains its semantically related entities, and wherein the co-occurrence is an instance of an entity of plurality of entities identified by an entry of the one or more entries in the entity co-occurrence database, and wherein the semantically-related entity corresponds to a model indicating distinct entities, assigning, by the entity extraction computer, an index identifier (index ID) to each of the entities in the plurality of extracted entities; disambiguating, by the entity extraction computer, each of the entities in the plurality of extracted entities from one another based on relatedness of index IDs; identifying, by the entity extraction computer, a subset of entities associated with each of the entities in the plurality of extracted entities based on relatedness of index IDs; linking, by the entity extraction computer, each entity to the associated subset of entities based at least on confidence scores; saving, by the entity extraction computer, the index ID for each of the plurality of extracted entities in the electronic data corpus, the electronic data corpus being indexed by an index ID corresponding to each of the one or more related entities; searching, by a search server computer, the entity indexed electronic data corpus to locate the plurality of extracted entities and identify index IDs of data records in which at least two of the plurality of extracted entities co-occur; and building, by the search server computer, a search result list having data records corresponding to the identified index IDs.
13. A non-transitory computer readable medium having stored thereon computer executable instructions comprising: receiving, by an entity extraction computer, user input of search query parameters; extracting, by the entity extraction computer, a plurality of entities from the search query parameters by comparing each entity in the plurality of extracted entities with an entity co-occurrence in-memory database that includes a confidence score indicative of a degree of certainty of co-occurrence of an extracted entity with one or more related entities in an electronic data corpus, wherein the entity co-occurrence database further comprises one or more entries for the plurality of entities, and wherein each entry of the one or more entries for a given entity of the plurality of entities contains its semantically related entities, and wherein the co-occurrence is an instance of an entity of plurality of entities identified by an entry of the one or more entries in the entity co-occurrence database, and wherein the semantically-related entity corresponds to a model indicating distinct entities, assigning, by the entity extraction computer, an index identifier (index ID) to each of the entities in the plurality of extracted entities; disambiguating, by the entity extraction computer, each of the entities in the plurality of extracted entities from one another based on relatedness of index IDs; identifying, by the entity extraction computer, a subset of entities associated with each of the entities in the plurality of extracted entities based on relatedness of index IDs; linking, by the entity extraction computer, each entity to the associated subset of entities based at least on confidence scores; saving, by the entity extraction computer, the index ID for each of the plurality of extracted entities in the electronic data corpus, the electronic data corpus being indexed by an index ID corresponding to each of the one or more related entities; searching, by a search server computer, the entity indexed electronic data corpus to locate the plurality of extracted entities and identify index IDs of data records in which at least two of the plurality of extracted entities co-occur; and building, by the search server computer, a search result list having data records corresponding to the identified index IDs. 16. The computer readable medium of claim 13 wherein the instructions further comprise associating, by the entity extraction computer, an extracted entity with one or more co-occurring entities in the entity indexed electronic data corpus.