clickhouse 自用语句记录

聚合查询：

SELECT 
    toStartOfInterval(CREATE_TIME, INTERVAL 60 SECOND) AS interval_start,
    ROUND(AVG(CPU_USED), 1) AS avg_cpu_used,
    ROUND(AVG(MEMORY_USED), 1) AS avg_memory_used,
    ROUND(AVG(DISK_USED), 1) AS avg_disk_used
FROM MWLOGDB_ANALYSIS.SYSTEM_MONITOR
GROUP BY interval_start
ORDER BY interval_start;

此语句的作用为：以60s聚合数据，并且只保留小数点后一位值