Mysql performance

1. max_connections open_files_limit table_open_cache 如何配置

table_open_cache = max_connections * N (N is the maximun number of tables open in each connection)

open_files_limit = 2*table_open_cache (open one table needs at least one file handler and another one for index, index file handler can share for the same table)

2. wait_timeout interactive_timeout 如何配置？

3. view algorithm: merge temptable undefined

build view from another view will have bad performance

4.