There are different modes of word storage which are currently supported by mnoGoSearch: "single","multi". Default mode is "single". Mode can be selected using DBMode part of DBAddr command in both indexer.conf and search.htm files.
Examples: DBAddr mysql://localhost/test/?DBMode=single DBAddr mysql://localhost/test/?DBMode=multi
When "single" is specified, all words are stored in a signle table with structure (url_id,word,weight), where url_id is the ID of the document which is referenced by rec_id field in "url" table. Word has variable char(32) SQL type. Each appearance of the same word in a document produces a separate record in the table.
If "multi" is selected, words are located in 256 separate tables using hash function for distribution. Structures of these tables are almost the same with "single" mode, but all word appearance are groupped into a single binary array, instead of producing multiple records. This fact makes "multi" mode much faster comparing with "single" mode.
"single" and "multi" modes support substring search. An SQL query containing LIKE predicate is executed internally in order to do substring search.