Business requirements: millions of level of a third party by the data of multiple databases of data sources, do show form (page) or statistics charts,
Solution a: check the third party database data directly, speed is slow, cannot control,
Scheme 2: data copy to your mysql database, making some optimization, data query speed could be better,
Solution 3: data copy to redis, if only paging query, fast, if fuzzy query or the data field data statistical analysis can also so fast?