5. A system comprising: one or more data processing devices; and one or more tangible computer-readable storage media having stored thereon computer executable components comprising: a storage module configured to store an inverted index of documents in the system and forward indices corresponding to each of the documents; an input module configured to receive an inquiry word; and a search module configured to segment the inquiry word into one or more keywords, search the inverted index to determine one or more documents in which one or more of the keywords are matched, search a forward index of a respective document of the determined one or more documents to generate an abstract for the respective document, the search including: determining a length limit of the abstract; identifying a plurality of portions within the respective document, each portion of the plurality of portions including a respective beginning position in the respective document and a respective ending position in the respective document, the identifying including identifying, within the respective document, every portion that is within the length limit by traversing the forward index character-by-character or word-by-word; finding a portion among the plurality of portions, the portion including a highest number of the one or more keywords between a beginning position and an ending position compared with any other portion of the plurality of portions; and selecting the found portion to be the abstract of the respective document.
5. A system comprising: one or more data processing devices; and one or more tangible computer-readable storage media having stored thereon computer executable components comprising: a storage module configured to store an inverted index of documents in the system and forward indices corresponding to each of the documents; an input module configured to receive an inquiry word; and a search module configured to segment the inquiry word into one or more keywords, search the inverted index to determine one or more documents in which one or more of the keywords are matched, search a forward index of a respective document of the determined one or more documents to generate an abstract for the respective document, the search including: determining a length limit of the abstract; identifying a plurality of portions within the respective document, each portion of the plurality of portions including a respective beginning position in the respective document and a respective ending position in the respective document, the identifying including identifying, within the respective document, every portion that is within the length limit by traversing the forward index character-by-character or word-by-word; finding a portion among the plurality of portions, the portion including a highest number of the one or more keywords between a beginning position and an ending position compared with any other portion of the plurality of portions; and selecting the found portion to be the abstract of the respective document. 13. The system of claim 5 , further comprising an output module configured to output the abstract as a search result.