Function isExecOnRep

src/proxy/execute.go:273–287

isExecOnRep will be called when the query is not in multi-statement txn: 1. When the query is Select, the parameter `loadBalance` can take effect. 2. By using hint can directly decide the load-balance mode, instead of check `loadBalance`.

(loadBalance int, node sqlparser.Statement)

// 1. When the query is Select, the parameter `loadBalance` can take effect.
// 2. By using hint can directly decide the load-balance mode, instead of check `loadBalance`.
func isExecOnRep(loadBalance int, node sqlparser.Statement) bool {
	if node, ok := node.(*sqlparser.Select); ok {
		if len(node.Comments) > 0 {
			comment := strings.Replace(common.BytesToString(node.Comments[0]), " ", "", -1)
			if comment == "/*+loadbalance=0*/" {
				return false
			}
			if comment == "/*+loadbalance=1*/" {
				return true
			}
		}
		return loadBalance != 0
	}
	return false
}