我該如何優化這些oracle查詢集

Question

我正在瀏覽一些沒有評論的pl/sql代碼。嘗試理解並優化它。下面是示例：

INSERT INTO gtt1 --75711 rows 
(USER_ID, role_id, participant_code, status_id) 
SELECT 
r.user_id, r.role_id, r.participant_code, MAX(status_id) 
FROM 
    user_role r, 
    cmp_role c 
WHERE 
    r.role_id = c.role_id 
    AND r.participant_code IS NOT NULL 
    AND c.group_id = 3 
    GROUP BY 
    r.user_id, r.role_id, r.participant_code; 

然後

DELETE gtt1 
WHERE ROWID IN (SELECT ROWID FROM gtt1 
       MINUS 
       SELECT a.ROWID FROM gtt1 a, UIV_CMP_USER_ROLE b 
       WHERE a.status_id = b.status_id 
       AND (b.ACTIVE = 1 OR (b.ACTIVE IN (0,3) 
         AND SYSDATE BETWEEN b.effective_from_date AND b.effective_to_date 
        ) 
       ) 
       ); 

最後（這需要最長）

OPEN cv_1 FOR 

SELECT c.role_id, 
     c.subgroup, 
     c.subgroup_description, 
     COUNT(a.USER_ID) user_count 
FROM 
    (SELECT b.user_id, b.role_id FROM gtt1 b, pt_user e 
    --pt_user table has 73000 rows 
     WHERE e.user_id = RTRIM(b.user_id) 
     ) a 
RIGHT OUTER JOIN CMP_ROLE c ON a.role_id = c.role_id 
WHERE c.group_id = v_group_id 
GROUP BY c.role_id,c.subgroup,c.subgroup_description 
ORDER BY c.subgroup; 

有沒有一種方法可以讓我避免gtt1刪除，最初只得到行我們想？

運行解釋計劃我注意到這個查詢的一些全表掃描：

SELECT 
    r.user_id, r.role_id, r.participant_code, MAX(status_id) 
    FROM 
    user_role r, 
    cmp_role c 
    WHERE 
    r.role_id = c.role_id 
    AND r.participant_code IS NOT NULL 
    AND c.group_id = 3 
    GROUP BY 
    r.user_id, r.role_id, r.participant_code 
    HAVING MAX(status_id) IN (SELECT b.status_id FROM UIV_CMP_USER_ROLE b 
           WHERE (b.ACTIVE = 1 OR (b.ACTIVE IN (0,3) 
            AND SYSDATE BETWEEN b.effective_from_date AND b.effective_to_date 
            )) 
          ) 

USER_ROLE = 803507行

cmp_role = 27行

user_role的有5個指標：

idx 1 = role_id

IDX 2 = last_updt_user_id

IDX 3 = actv_id，participant_code，effective_from_Date，effective_to_date

IDX 4 = USER_ID，ROLE_ID，effective_from_Date，effective_to_date

IDX 5 = participant_code，USER_ID，roke_id，actv_cd

Answer 1

插入和刪除在我看來是相同的：

INSERT INTO gtt1 --75711 rows 
(USER_ID, role_id, participant_code, status_id) 
SELECT 
r.user_id, r.role_id, r.participant_code, MAX(status_id) 
FROM 
    user_role r, 
    cmp_role c 
WHERE 
    r.role_id = c.role_id 
    AND r.participant_code IS NOT NULL 
    AND c.group_id = 3 
    GROUP BY 
    r.user_id, r.role_id, r.participant_code 
    HAVING MAX(status_id) IN (SELECT b.status_id FROM UIV_CMP_USER_ROLE b 
          WHERE (b.ACTIVE = 1 OR (b.ACTIVE IN (0,3) 
            AND SYSDATE BETWEEN b.effective_from_date 
               AND b.effective_to_date 
           )) 
          ); 

這是否是更有效的，我不知道 - 我需要更多地瞭解表格，索引和數據。

你可以去再進一步，並打開GTT爲子查詢，例如：

WITH gtt1 AS 
    (SELECT 
    r.user_id, r.role_id, r.participant_code, MAX(status_id) 
    FROM 
    user_role r, 
    cmp_role c 
    WHERE 
    r.role_id = c.role_id 
    AND r.participant_code IS NOT NULL 
    AND c.group_id = 3 
    GROUP BY 
    r.user_id, r.role_id, r.participant_code 
    HAVING MAX(status_id) IN (SELECT b.status_id FROM UIV_CMP_USER_ROLE b 
           WHERE (b.ACTIVE = 1 OR (b.ACTIVE IN (0,3) 
            AND SYSDATE BETWEEN b.effective_from_date AND b.effective_to_date 
            )) 
          ) 
) 
SELECT c.role_id, 
     c.subgroup, 
     c.subgroup_description, 
     COUNT(a.USER_ID) user_count 
FROM 
    (SELECT b.user_id, b.role_id FROM gtt1 b, pt_user e 
    --pt_user table has 73000 rows 
     WHERE e.user_id = RTRIM(b.user_id) 
     ) a 
RIGHT OUTER JOIN CMP_ROLE c ON a.role_id = c.role_id 
WHERE c.group_id = v_group_id 
GROUP BY c.role_id,c.subgroup,c.subgroup_description 
ORDER BY c.subgroup; 

同樣，我不知道這是否是比當前代碼或多或少效率。

Answer 2

你想優化查詢本身還是隻需要花費時間來給出結果？ 其次大約需要行數的一些數據等等...