AWR on PolloChang 工作筆記

oracle AWR TOP SQL

Thu, 15 Jan 2026 23:23:49 +0800

以下我針對 AWR 中的 TOP SQL 進行研究

SQL ordered by Elapsed Time
SQL ordered by CPU Time
SQL ordered by User I/O Wait Time
SQL ordered by Gets
SQL ordered by Reads
SQL ordered by Physical Reads (UnOptimized)
SQL ordered by Executions
SQL ordered by Parse Calls
SQL ordered by Sharable Memory
SQL ordered by Version Count

尋找方式
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1. SQL ordered by TOP Event
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WITH sql_metrics AS (
    -- 1. 從歷史視圖中加總各項增量指標
    SELECT 
        s.sql_id,
        SUM(s.elapsed_time_delta) / 1000000 as total_elapsed_sec,
        SUM(s.cpu_time_delta) / 1000000 as total_cpu_sec,
        SUM(s.iowait_delta) / 1000000 as total_io_wait_sec,
        SUM(s.buffer_gets_delta) as total_gets,
        SUM(s.disk_reads_delta) as total_reads,
        -- Physical Reads (UnOptimized) 通常是指排除掉從 Flash Cache 讀取的真正磁碟讀取
        SUM(s.physical_read_requests_delta) as total_phys_read_req,
        SUM(s.executions_delta) as total_execs,
        SUM(s.parse_calls_delta) as total_parse_calls,
        -- 這些是目前快照點的狀態值，取最大值作為參考
        MAX(s.sharable_mem) / 1024 / 1024 as max_sharable_mem_mb,
        MAX(s.version_count) as max_version_count
    FROM dba_hist_sqlstat s
    JOIN dba_hist_snapshot sn ON s.snap_id = sn.snap_id AND s.dbid = sn.dbid AND s.instance_number = sn.instance_number
    WHERE sn.begin_interval_time >= SYSDATE - 1
    GROUP BY s.sql_id
),
ranked_sql AS (
    -- 2. 針對各個維度進行排名
    SELECT 
        m.*,
        RANK() OVER (ORDER BY total_elapsed_sec DESC) as rank_elapsed,
        RANK() OVER (ORDER BY total_cpu_sec DESC) as rank_cpu,
        RANK() OVER (ORDER BY total_io_wait_sec DESC) as rank_io,
        RANK() OVER (ORDER BY total_gets DESC) as rank_gets,
        RANK() OVER (ORDER BY total_reads DESC) as rank_reads,
        RANK() OVER (ORDER BY total_phys_read_req DESC) as rank_unoptimized,
        RANK() OVER (ORDER BY total_execs DESC) as rank_execs,
        RANK() OVER (ORDER BY total_parse_calls DESC) as rank_parse,
        RANK() OVER (ORDER BY max_sharable_mem_mb DESC) as rank_mem,
        RANK() OVER (ORDER BY max_version_count DESC) as rank_version
    FROM sql_metrics m
)
-- 3. 結合 SQL 文字並輸出 (此處以 Elapsed Time 前 20 名為例)
SELECT * FROM (
    SELECT 
        r.sql_id,
        r.total_elapsed_sec as "Elapsed(s)",
        r.total_cpu_sec as "CPU(s)",
        r.total_io_wait_sec as "IO_Wait(s)",
        r.total_gets as "Gets",
        r.total_reads as "Reads",
        r.total_execs as "Execs",
        r.total_parse_calls as "Parses",
        ROUND(r.max_sharable_mem_mb, 2) as "Mem(MB)",
        r.max_version_count as "Versions",
        -- 顯示前 100 個字元的 SQL 文字
        DBMS_LOB.SUBSTR(st.sql_text, 100, 1) as sql_snippet
    FROM ranked_sql r
    LEFT JOIN dba_hist_sqltext st ON r.sql_id = st.sql_id
    -- 你可以更換下方的排序條件來查看不同的 TOP 榜單
    ORDER BY r.rank_elapsed ASC 
) WHERE ROWNUM <= 20

執行結果範例

oracle AWR PERF TREND HISTORY

Thu, 15 Jan 2026 21:23:49 +0800

最近常常接觸 AWR 報表分析，想說AWR已經有儲存資料庫運作歷史資訊，為何不依據裡頭的紀錄資訊進行效能分析呢？因此開始著手研究如何將AWR的資料呈現出趨勢資料～

Oracle AWR 常用筆記

Fri, 02 Jan 2026 20:57:49 +0800

--手動執行快照
exec DBMS_WORKLOAD_REPOSITORY.CREATE_SNAPSHOT();

-- 設定AWR 快照區間
BEGIN
  DBMS_WORKLOAD_REPOSITORY.MODIFY_SNAPSHOT_SETTINGS(
    retention => 259200,   -- 以分鐘為單位 (7天 = 7 * 24 * 60)
    interval  => 10        -- 以分鐘為單位
  );
END;

-- 查詢 AWR 資料範圍
select SNAP_ID,DBID,INSTANCE_NUMBER,BEGIN_INTERVAL_TIME,END_INTERVAL_TIME 
FROM awr_pdb_snapshot 
WHERE
END_INTERVAL_TIME >= to_date('2025-12-27 22:55:00','yyyy-mm-dd hh24:mi:ss') 
AND BEGIN_INTERVAL_TIME <= to_date('2025-12-28 05:20:00','yyyy-mm-dd hh24:mi:ss') 
AND INSTANCE_NUMBER=1 
ORDER BY SNAP_ID;

-- 輸出 AWR HTML
SELECT 
DBMS_WORKLOAD_REPOSITORY.AWR_REPORT_HTML(1979277899,1,88, 89)
FROM dual;

--輸出AWR TEXT
SELECT output FROM TABLE(
   DBMS_WORKLOAD_REPOSITORY.AWR_REPORT_TEXT(1979277899,1,88, 89)
  );

SELECT output FROM TABLE(
   DBMS_WORKLOAD_REPOSITORY.AWR_REPORT_HTML(1979277899,1,88, 89)
  );

--匯出 AWR 所有資料
 
EXECUTE DBMS_WORKLOAD_REPOSITORY.AWR_EXP(
dmpfile => ‘awrdat’,
dmpdir => ‘DATA_PUMP_DIR’,
bid => 1,
eid => 1000000
);

--匯入 AWR 所有資料

EXECUTE DBMS_WORKLOAD_REPOSITORY.AWR_IMP(
dmpfile => ‘awrdat’,
dmpdir => ‘DATA_PUMP_DIR’
);

-- AWR 空間使用率
SELECT space_usage_kbytes/1024 MB_used 
FROM v$sysaux_occupants 
WHERE occupant_name='SM/AWR';

generate_awr.sh

#!/bin/bash
ORACLE_SID=ORCLCDB
ORACLE_HOME=/u01/app/oracle/product/19.3/dbhome_1
REPORT_FILE="awr_report_$(date +%Y%m%d).html"

sqlplus -s / as sysdba <<EOF
set pages 0 lines 200 feedback off
spool $REPORT_FILE
SELECT dbms_workload_repository.awr_report_html(
  (SELECT dbid FROM v\$database),
  (SELECT instance_number FROM v\$instance),
  (SELECT MAX(snap_id)-1 FROM dba_hist_snapshot),
  (SELECT MAX(snap_id) FROM dba_hist_snapshot)
) FROM dual;
spool off
EOF

echo "AWR報告路徑：$REPORT_FILE"

AWR on PolloChang 工作筆記

oracle AWR TOP SQL

尋找方式 #

1. SQL ordered by TOP Event #

oracle AWR PERF TREND HISTORY

Oracle AWR 常用筆記

Reference #

尋找方式
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1. SQL ordered by TOP Event
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Reference
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