GBase 8s 使用sqltrace跟踪sql性能
SQLTrace用于跟踪执行sql的性能，可用于定位性能较差的sql，从而进行优化。
Example
打开sqltrace跟踪15000条sql，所需内存：15000*4k=60MB
1 2 3 | dbaccess sysadmin - <<!EXECUTE FUNCTION task("set sql tracing on","15000","4","high","global");! |
查看执行耗时较长sql：
1 2 3 4 5 | dbaccess sysmaster -<<!unload to sql.unl select sql_maxtime,sql_avgtime,sql_statement from syssqltrace order by sql_maxtime desc;! |
查看当前路径下生成的sql.unl文件
查询跟踪信息，根据需要排序
1 2 3 | dbaccess sysmaster - <<!select * from syssqltrace;! |
命令查看trace信息：
1 | onstat -g his |
关闭sqltrace
1 2 3 | dbaccess sysadmin - <<!EXECUTE FUNCTION task("set sql tracing off");! |