Grails provide you to log all the hibernate queries by setting logSql=true in the DataSource.groovy file like:

environments {
    development {
        dataSource {
            ...
            logSql = true
        }
    }
    ...

But native SQL queries are not logged.

To log the SQL queries add groovy.sql in you log4j configurations in Config.groovy file

log4j = {
    ...
    debug 'groovy.sql'
    ...
}

and add log level in BootStrap.groovy

import groovy.sql.Sql
import java.util.logging.Level

class BootStrap {

    def init = { servletContext ->
        Sql.LOG.level = Level.FINE
        ...
    }

    def destroy = {}
}

that’s all, run your application and you got all native SQL queries in the logs.