5. A method comprising: identifying a file for a long-query; decomposing the file into parts comprising topic-related words and file-specific words, the file-specific words being separate from the topic-related words; representing a decomposed file with a vector and at least one keyword from the file-specific words; selecting a candidate set of files for a long-query result based at least on the vector; ranking the files in the candidate set of files for the long-query result based on the at least one keyword; and returning files in the candidate set of files for the long-query result based at least on the ranking.
5. A method comprising: identifying a file for a long-query; decomposing the file into parts comprising topic-related words and file-specific words, the file-specific words being separate from the topic-related words; representing a decomposed file with a vector and at least one keyword from the file-specific words; selecting a candidate set of files for a long-query result based at least on the vector; ranking the files in the candidate set of files for the long-query result based on the at least one keyword; and returning files in the candidate set of files for the long-query result based at least on the ranking. 7. A method as recited in claim 5 , further comprising determining a file topic corresponding to each of the candidate set of files.