package database/sql
SetMaxOpenConns sets the maximum number of open connections to the database.
If MaxIdleConns is greater than 0 and the new MaxOpenConns is less than MaxIdleConns, then MaxIdleConns will be reduced to match the new MaxOpenConns limit
If n <= 0, then there is no limit on the number of open connections. The default is 0 (unlimited).
Golang database/sql.DB.SetMaxOpenConns function usage examples
Example 1:
const defaultMaxIdleConns = 2
// Start by opening defaultMaxIdleConns
rows := make([]*Rows, defaultMaxIdleConns)
// We need to SetMaxOpenConns > MaxIdleConns, so the DB can open
// a new connection and we can fill the idle queue with the released
// connections.
db.SetMaxOpenConns(len(rows) + 1) // <-- here
Example 2:
db.SetMaxIdleConns(1)
db.SetMaxOpenConns(2)
Reference :
http://golang.org/pkg/database/sql/#DB.SetMaxOpenConns
