This database includes all the US indexes that are part of the S&P 500, 400, 600, and 1500 which is about 1000 indexes. It includes all 4 levels of the GICS for these market cap breakdowns and also some of the composite, growth and value indexes. The fields included are Index Group which names what market cap breakdown (100, 400, etc.) they fall in and another field for GICS Level (Sector, Industry Group, Industry, Sub-Industry). For example, you can query on all indexes in the S&P 500 at the Sector level. I have also included the Market Cap, Constituents (number of stocks in index) and dividend yield of the index.