PHP connection multiple db, time-out related issues

PHP connection multiple db, time-out problem
RT, now I have multiple libraries, some are on different physical machines, each library has the same table, now need to query each library the same table data set display, how to solve this problem?
Now I use the method is each DB to establish a connection, query and then output the page, thousands of DB case is very slow, and there is no 504 timeout situation, ask-0-, online and so on!!
------Solution--------------------
The remotely connected database is always slow, and you can try to use a database service that supports distributed databases instead
such as Oracle, SQL Server
------Solution--------------------
On different physical machines, there are also thousands of db, which is sure to be slow, you can cache the results of the first query, and then the query can be retrieved from the cache.

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