1. A method comprising: receiving, by a search engine executed by a processor device, a request to access target data, wherein the target data is stored in at least one of a plurality of data sources, each of the plurality of data sources having a respective candidate index; extracting, by the search engine, a plurality of inquiry parameters from the request, wherein each inquiry parameter corresponds to a sub-index of a respective general index, each sub-index comprising a subset of the respective general index, wherein each general index comprises an index of relationships between data from at least two of the plurality of data sources; performing, by the search engine, parallel searches of the general indices common to the plurality of data sources, wherein each parallel search comprises searching a plurality of sub-indices for the general indices common to the plurality of data sources based on one or more corresponding inquiry parameters for the plurality of sub-indices; performing, by the search engine, one or more additional parallel searches of the candidate indices based on results of the parallel searches of general indices unioned with inquiry parameters; and extracting, by the search engine, an output based on results returned from the one or more additional parallel searches of the candidate indices.