最新国产好看的视频,伊人天堂AV在线,国产Aaaaaa视频,蜜臀视频在线观看一区,人妻av色图,密臀久久久精品影片,青青视频免费观看毛片,久草在线观看视,国产三级精品色情在线

分析Mysql表讀寫、索引等操作的sql語句效率優(yōu)化問題

 更新時(shí)間:2018年12月08日 10:36:58   作者:執(zhí)筆記憶的空白  
今天小編就為大家分享一篇關(guān)于分析Mysql表讀寫、索引等操作的sql語句效率優(yōu)化問題,小編覺得內(nèi)容挺不錯(cuò)的,現(xiàn)在分享給大家,具有很好的參考價(jià)值,需要的朋友一起跟隨小編來看看吧

上次我們說到mysql的一些sql查詢方面的優(yōu)化,包括查看explain執(zhí)行計(jì)劃,分析索引等等。今天我們分享一些 分析mysql表讀寫、索引等等操作的sql語句。

閑話不多說,直接上代碼:

反映表的讀寫壓力

SELECT file_name AS file,
    count_read,
    sum_number_of_bytes_read AS total_read,
    count_write,
    sum_number_of_bytes_write AS total_written,
    (sum_number_of_bytes_read + sum_number_of_bytes_write) AS total
 FROM performance_schema.file_summary_by_instance
ORDER BY sum_number_of_bytes_read+ sum_number_of_bytes_write DESC;

反映文件的延遲

SELECT (file_name) AS file,
    count_star AS total,
    CONCAT(ROUND(sum_timer_wait / 3600000000000000, 2), 'h') AS total_latency,
    count_read,
    CONCAT(ROUND(sum_timer_read / 1000000000000, 2), 's') AS read_latency,
    count_write,
    CONCAT(ROUND(sum_timer_write / 3600000000000000, 2), 'h')AS write_latency
 FROM performance_schema.file_summary_by_instance
ORDER BY sum_timer_wait DESC;

table 的讀寫延遲

SELECT object_schema AS table_schema,
       object_name AS table_name,
       count_star AS total,
       CONCAT(ROUND(sum_timer_wait / 3600000000000000, 2), 'h') as total_latency,
       CONCAT(ROUND((sum_timer_wait / count_star) / 1000000, 2), 'us') AS avg_latency,
       CONCAT(ROUND(max_timer_wait / 1000000000, 2), 'ms') AS max_latency
 FROM performance_schema.objects_summary_global_by_type
    ORDER BY sum_timer_wait DESC;

查看表操作頻度

SELECT object_schema AS table_schema,
      object_name AS table_name,
      count_star AS rows_io_total,
      count_read AS rows_read,
      count_write AS rows_write,
      count_fetch AS rows_fetchs,
      count_insert AS rows_inserts,
      count_update AS rows_updates,
      count_delete AS rows_deletes,
       CONCAT(ROUND(sum_timer_fetch / 3600000000000000, 2), 'h') AS fetch_latency,
       CONCAT(ROUND(sum_timer_insert / 3600000000000000, 2), 'h') AS insert_latency,
       CONCAT(ROUND(sum_timer_update / 3600000000000000, 2), 'h') AS update_latency,
       CONCAT(ROUND(sum_timer_delete / 3600000000000000, 2), 'h') AS delete_latency
   FROM performance_schema.table_io_waits_summary_by_table
    ORDER BY sum_timer_wait DESC ;

索引狀況

SELECT OBJECT_SCHEMA AS table_schema,
        OBJECT_NAME AS table_name,
        INDEX_NAME as index_name,
        COUNT_FETCH AS rows_fetched,
        CONCAT(ROUND(SUM_TIMER_FETCH / 3600000000000000, 2), 'h') AS select_latency,
        COUNT_INSERT AS rows_inserted,
        CONCAT(ROUND(SUM_TIMER_INSERT / 3600000000000000, 2), 'h') AS insert_latency,
        COUNT_UPDATE AS rows_updated,
        CONCAT(ROUND(SUM_TIMER_UPDATE / 3600000000000000, 2), 'h') AS update_latency,
        COUNT_DELETE AS rows_deleted,
        CONCAT(ROUND(SUM_TIMER_DELETE / 3600000000000000, 2), 'h')AS delete_latency
FROM performance_schema.table_io_waits_summary_by_index_usage
WHERE index_name IS NOT NULL
ORDER BY sum_timer_wait DESC;

全表掃描情況

SELECT object_schema,
    object_name,
    count_read AS rows_full_scanned
 FROM performance_schema.table_io_waits_summary_by_index_usage
WHERE index_name IS NULL
  AND count_read > 0
ORDER BY count_read DESC;

沒有使用的index

SELECT object_schema,
    object_name,
    index_name
  FROM performance_schema.table_io_waits_summary_by_index_usage
 WHERE index_name IS NOT NULL
  AND count_star = 0
  AND object_schema not in ('mysql','v_monitor')
  AND index_name <> 'PRIMARY'
 ORDER BY object_schema, object_name;

糟糕的sql問題摘要

SELECT (DIGEST_TEXT) AS query,
    SCHEMA_NAME AS db,
    IF(SUM_NO_GOOD_INDEX_USED > 0 OR SUM_NO_INDEX_USED > 0, '*', '') AS full_scan,
    COUNT_STAR AS exec_count,
    SUM_ERRORS AS err_count,
    SUM_WARNINGS AS warn_count,
    (SUM_TIMER_WAIT) AS total_latency,
    (MAX_TIMER_WAIT) AS max_latency,
    (AVG_TIMER_WAIT) AS avg_latency,
    (SUM_LOCK_TIME) AS lock_latency,
    format(SUM_ROWS_SENT,0) AS rows_sent,
    ROUND(IFNULL(SUM_ROWS_SENT / NULLIF(COUNT_STAR, 0), 0)) AS rows_sent_avg,
    SUM_ROWS_EXAMINED AS rows_examined,
    ROUND(IFNULL(SUM_ROWS_EXAMINED / NULLIF(COUNT_STAR, 0), 0)) AS rows_examined_avg,
    SUM_CREATED_TMP_TABLES AS tmp_tables,
    SUM_CREATED_TMP_DISK_TABLES AS tmp_disk_tables,
    SUM_SORT_ROWS AS rows_sorted,
    SUM_SORT_MERGE_PASSES AS sort_merge_passes,
    DIGEST AS digest,
    FIRST_SEEN AS first_seen,
    LAST_SEEN as last_seen
  FROM performance_schema.events_statements_summary_by_digest d
where d
ORDER BY SUM_TIMER_WAIT DESC
limit 20;

掌握這些sql,你能輕松知道你的庫那些表存在問題,然后考慮怎么去優(yōu)化。   

總結(jié)

以上就是這篇文章的全部內(nèi)容了,希望本文的內(nèi)容對(duì)大家的學(xué)習(xí)或者工作具有一定的參考學(xué)習(xí)價(jià)值,謝謝大家對(duì)腳本之家的支持。如果你想了解更多相關(guān)內(nèi)容請(qǐng)查看下面相關(guān)鏈接

相關(guān)文章

  • 一文學(xué)習(xí)MySQL?意向共享鎖、意向排他鎖、死鎖

    一文學(xué)習(xí)MySQL?意向共享鎖、意向排他鎖、死鎖

    這篇文章主要介紹了MySQL?意向共享鎖、意向排他鎖、死鎖,包括InnoDB表級(jí)鎖,意向共享鎖和意向排他鎖及操作方法,本文給大家介紹的非常詳細(xì),需要的朋友可以參考下
    2022-03-03
  • MySQL中select語句使用order按行排序

    MySQL中select語句使用order按行排序

    本文介紹MySQL數(shù)據(jù)庫中執(zhí)行select查詢語句,并對(duì)查詢的結(jié)果使用order by 子句進(jìn)行排序
    2016-04-04
  • mysql分表之后如何平滑上線詳解

    mysql分表之后如何平滑上線詳解

    項(xiàng)目開發(fā)中,我們的數(shù)據(jù)庫數(shù)據(jù)越來越大,隨之而來的是單個(gè)表中數(shù)據(jù)太多,以至于查詢書讀變慢,當(dāng)出現(xiàn)這種情況時(shí),我們可以考慮分表,這篇文章主要給大家介紹了關(guān)于mysql分表之后如何平滑上線的相關(guān)資料,需要的朋友可以參考下
    2021-10-10
  • Mysql Binlog快速遍歷搜索記錄及binlog數(shù)據(jù)查看的方法

    Mysql Binlog快速遍歷搜索記錄及binlog數(shù)據(jù)查看的方法

    這篇文章主要介紹了Mysql Binlog快速遍歷搜索記錄及binlog數(shù)據(jù)查看的方法的相關(guān)資料,需要的朋友可以參考下
    2016-01-01
  • MySQL數(shù)據(jù)庫之聯(lián)合查詢?union

    MySQL數(shù)據(jù)庫之聯(lián)合查詢?union

    這篇文章主要介紹了MySQL數(shù)據(jù)庫之聯(lián)合查詢?union,聯(lián)合查詢就是將多個(gè)查詢結(jié)果的結(jié)果集合并到一起,字段數(shù)不變,多個(gè)查詢結(jié)果的記錄數(shù)合并,下文詳細(xì)介紹需要的小伙伴可以參考一下
    2022-06-06
  • mysql數(shù)據(jù)庫的五種安裝方式總結(jié)

    mysql數(shù)據(jù)庫的五種安裝方式總結(jié)

    這篇文章主要介紹了五種在不同操作系統(tǒng)上安裝和配置MySQL的方法,包括Windows版本安裝、yum倉庫安裝、二進(jìn)制本地安裝、容器平臺(tái)安裝以及源碼部署,每種方法都介紹的非常詳細(xì),需要的朋友可以參考下
    2025-03-03
  • MySQL數(shù)據(jù)庫備份方法說明

    MySQL數(shù)據(jù)庫備份方法說明

    MySQL數(shù)據(jù)庫備份方法說明...
    2007-07-07
  • mysql存儲(chǔ)過程中使用游標(biāo)的實(shí)例

    mysql存儲(chǔ)過程中使用游標(biāo)的實(shí)例

    使用MYSQL存儲(chǔ)過程,可以實(shí)現(xiàn)諸多的功能,下面將為您介紹一個(gè)MYSQL存儲(chǔ)過程中使用游標(biāo)的實(shí)例
    2014-01-01
  • MySQL定時(shí)備份數(shù)據(jù)庫(全庫備份)的實(shí)現(xiàn)

    MySQL定時(shí)備份數(shù)據(jù)庫(全庫備份)的實(shí)現(xiàn)

    本文主要介紹了MySQL定時(shí)備份數(shù)據(jù)庫(全庫備份)的實(shí)現(xiàn),文中通過示例代碼介紹的非常詳細(xì),具有一定的參考價(jià)值,感興趣的小伙伴們可以參考一下
    2021-09-09
  • MySQL 子查詢和分組查詢

    MySQL 子查詢和分組查詢

    這篇文章主要介紹了MySQL 子查詢和分組查詢的相關(guān)資料,幫助大家更好的理解MySQL查詢的相關(guān)知識(shí),感興趣的朋友可以了解下
    2020-11-11

最新評(píng)論

三原县| 临猗县| 咸丰县| 阿合奇县| 武强县| 治县。| 三门县| 竹北市| 黑龙江省| 喜德县| 新巴尔虎左旗| 石台县| 德格县| 达尔| 静海县| 宿州市| 长岛县| 桂东县| 始兴县| 柳州市| 高陵县| 镇巴县| 米泉市| 定西市| 晋州市| 日照市| 龙海市| 黑龙江省| 连江县| 柘荣县| 进贤县| 丽水市| 石柱| 吉隆县| 玉龙| 德江县| 南岸区| 长沙市| 绥芬河市| 右玉县| 新竹县|