Abstract: This invention allows keyword searches in both structured and unstructured databases, and across multiple databases of different vendors. An index database is created comprising word occurrences and table relationship information. In the case of unstructured databases with no predetermined schema, the relationship between different tables is derived through propagative n-level indexing and data is then populated in index tables. A database adapter enables indexing and searching across multi-vendor databases, which resolves discrepancies across different database access methodologies. Given a set of keyword inputs, the rows containing the search words and all the related rows are searched using word occurrences and relationship information.