UNION ALLビューの実行が非常に遅い

Question

私はTableauでのデータを準備しています。現在、私は巨大なUNION ALLスクリプト（2つのテーブルのみを示す添付）を使って1つの大きなビューに結合する約12のテーブルを持っています。

Tableauでの私のパフォーマンスは非常に遅く、データをより効率的に構築する方法があることは確かです。現在、私は15分ごとにタブロー抽出をリフレッシュしなければならないので、データは真に「生きている」わけではありません。

助けてください。 おかげであなたが提供するもので

DROP VIEW XXXXX_alerts; 
CREATE 
    ALGORITHM = UNDEFINED 
    DEFINER = root@% 
    SQL SECURITY DEFINER 
VIEW XXXXX_alerts AS 
    SELECT 
     _data435329_XXXXX_12_pre_tested_pipe_inspection_form.ID AS ID, 
     _data435329_XXXXX_12_pre_tested_pipe_inspection_form.inspector AS Inspector, 
     _data435329_XXXXX_12_pre_tested_pipe_inspection_form.CREATED_DATE AS Created_Date, 
     _data435329_XXXXX_12_pre_tested_pipe_inspection_form.CREATED_LOCATION AS Created_Location, 
     _data435329_XXXXX_12_pre_tested_pipe_inspection_form.MODIFIED_DATE AS Modified_Date, 
     _data435329_XXXXX_12_pre_tested_pipe_inspection_form.MODIFIED_LOCATION AS Modified_Location, 
     _data435329_XXXXX_12_pre_tested_pipe_inspection_form.date1 AS date1, 
     NULL AS test_date_8200B, 
     _data435329_XXXXX_12_pre_tested_pipe_inspection_form.division AS division, 
     '8900' AS Form, 
     NULL AS Device_Type, 
     _data435329_XXXXX_12_pre_tested_pipe_inspection_form.coating_condition AS coating_condition, 
     _data435329_XXXXX_12_pre_tested_pipe_inspection_form.next_calibration_date AS next_calibration_date, 
     _data435329_XXXXX_12_pre_tested_pipe_inspection_form.pipe_barcode AS pipe_barcode, 
     _data435329_XXXXX_12_pre_tested_pipe_inspection_form.nitrogen_pressure_when_left_psig AS nitrogen_pressure_when_left_psig, 
     _data435329_XXXXX_12_pre_tested_pipe_inspection_form.is_nitrogen_left_value_correct AS is_nitrogen_left_value_correct, 
     NULL AS Location, 
     NULL AS Location_Conditional_Value, 
     NULL AS Town, 
     NULL AS readily_detectable_reading, 
     NULL AS threshold_level_gas, 
     NULL AS hefpa_shutoff, 
     NULL AS customers_signature, 
     NULL AS street, 
     NULL AS serial_number, 
     NULL AS tubing_filter_replaced_date, 
     NULL AS calibration_date, 
     NULL AS holiday_equipment_type, 
     NULL AS date_tag_issued, 
     NULL AS class, 
     NULL AS condition1, 
     NULL AS action_taken, 
     NULL AS reinspect_complete, 
     NULL AS person_designation, 
     NULL AS apartment_complex, 
     NULL AS result_of_contact_1, 
     NULL AS result_of_contact_2, 
     NULL AS date_letter_sent, 
     NULL AS date_clerk_sent_letter_to_customer_advocate, 
     NULL AS excessive_co_reinspect, 
     NULL AS tag_cleared, 
     NULL AS condition, 
     NULL AS date_of_contact_to_customer_service_for_locked_off_meter, 
     NULL AS date_tag_cleared, 
     NULL AS type_of_fitting, 
     NULL AS re_inspected_by_company_employee, 
     NULL AS inspection_Result, 
     NULL AS wo_sap_number, 
     NULL AS material_studied, 
     NULL AS time_studied, 
     NULL AS program, 
     NULL AS cgi_or_fi, 
     NULL AS component_picture, 
     NULL AS Test_Pressure, 
     NULL AS Test_Duration, 
     NULL AS Pipe_Footage, 
     NULL AS Pipe_Size, 
     NULL AS Barcode, 
     NULL AS Material 
    FROM 
     _data435329_XXXXX_12_pre_tested_pipe_inspection_form 
    UNION ALL SELECT 
     _data435329_XXXXX_10_2_quantitative_odorant.ID AS ID, 
     _data435329_XXXXX_10_2_quantitative_odorant.inspector AS Inspector, 
     _data435329_XXXXX_10_2_quantitative_odorant.CREATED_DATE AS Created_Date, 
     _data435329_XXXXX_10_2_quantitative_odorant.CREATED_LOCATION AS Created_Location, 
     _data435329_XXXXX_10_2_quantitative_odorant.MODIFIED_DATE AS Modified_Date, 
     _data435329_XXXXX_10_2_quantitative_odorant.MODIFIED_LOCATION AS Modified_Location, 
     NULL AS date1, 
     _data435329_XXXXX_10_2_quantitative_odorant.date1 AS test_date_8200B, 
     _data435329_XXXXX_10_2_quantitative_odorant.division AS division, 
     '8200B' AS Form, 
     NULL AS Device_Type, 
     NULL AS coating_condition, 
     NULL AS next_calibration_date, 
     NULL AS pipe_barcode, 
     NULL AS nitrogen_pressure_when_left_psig, 
     NULL AS is_nitrogen_left_value_correct, 
     _data435329_XXXXX_10_2_quantitative_odorant.location1 AS Location, 
     zcoptions.CONDITION_VALUE AS Location_Conditional_Value, 
     _data435329_XXXXX_10_2_quantitative_odorant.town AS Town, 
     _data435329_XXXXX_10_2_quantitative_odorant.odorometer_read_quantitative_readily_detectable___ AS readily_detectable_reading, 
     _data435329_XXXXX_10_2_quantitative_odorant.odorometer_read_quantitative_threshold_level___gas AS threshold_level_gas, 
     NULL AS hefpa_shutoff, 
     NULL AS customers_signature, 
     NULL AS street, 
     NULL AS serial_number, 
     NULL AS tubing_filter_replaced_date, 
     NULL AS calibration_date, 
     NULL AS holiday_equipment_type, 
     NULL AS date_tag_issued, 
     NULL AS class, 
     NULL AS condition1, 
     NULL AS action_taken, 
     NULL AS reinspect_complete, 
     NULL AS person_designation, 
     NULL AS apartment_complex, 
     NULL AS result_of_contact_1, 
     NULL AS result_of_contact_2, 
     NULL AS date_letter_sent, 
     NULL AS date_clerk_sent_letter_to_customer_advocate, 
     NULL AS excessive_co_reinspect, 
     NULL AS tag_cleared, 
     NULL AS condition, 
     NULL AS date_of_contact_to_customer_service_for_locked_off_meter, 
     NULL AS date_tag_cleared, 
     NULL AS type_of_fitting, 
     NULL AS re_inspected_by_company_employee, 
     NULL AS inspection_Result, 
     NULL AS wo_sap_number, 
     NULL AS material_studied, 
     NULL AS time_studied, 
     NULL AS program, 
     NULL AS cgi_or_fi, 
     NULL AS component_picture, 
     NULL AS Test_Pressure, 
     NULL AS Test_Duration, 
     NULL AS Pipe_Footage, 
     NULL AS Pipe_Size, 
     NULL AS Barcode, 
     NULL AS Material 
    FROM 
     (_data435329_XXXXX_10_2_quantitative_odorant 
     LEFT JOIN zcoptions ON ((zcoptions.KEY_VALUE = _data435329_XXXXX_10_2_quantitative_odorant.location1))) 
    WHERE 
     (zcoptions.OPTION_LIST_ID = 4553158) 
    GROUP BY _data435329_XXXXX_10_2_quantitative_odorant.ID 
    UNION ALL SELECT 

Answer 1

、我々は唯一の

FROM (_data435329_XXXXX_10_2_quantitative_odorant 
    LEFT JOIN zcoptions 
      ON ((zcoptions.KEY_VALUE = 
       _data435329_XXXXX_10_2_quantitative_odorant.location1)) 
     ) 
    WHERE (zcoptions.OPTION_LIST_ID = 4553158) 
    GROUP BY _data435329_XXXXX_10_2_quantitative_odorant.ID 

WHERE (WHERE (zcoptions.OPTION_LIST_ID = 4553158) = 4553158)が効果的JOINにLEFT JOINをオンに対処することができます。だから、なぜあなたはJOINと言っていないのだろうか？

インデックス：

zcoptions: INDEX(OPTION_LIST_ID) 

か、それは "カバー" にする、それ故に多少速く：

zcoptions: INDEX(OPTION_LIST_ID, KEY_VALUE, CONDITION_VALUE) 

これはEAVスキーマのようなにおい。その場合は、PRIMARY KEYなどを設定するには、hereのアドバイスに従ってください。その他のキー値表の場合も同様です。

匂い次のものがこのパターンです：

FROM a JOIN b ... 
GROUP BY a.id 

は私がJOINは、最初の行の数を乗算しているため、「 - 破を爆発」と呼んで、そしてGROUP BYはバックの行ごとに1つの行にそれをもたらしますテーブルの1つ。

JOINには、それぞれにbの複数の行があり、aには、GROUP BYが不要です。 （データを知らなくても、私はこれを予測することはできません。）この場合、クエリを表現する別の方法は

SELECT 
    ..., 
    (SELECT CONDITION_VALUE 
     FROM zcoptions 
     WHERE KEY_VALUE = _data435329_XXXXX_10_2_quantitative_odorant.location1 
      AND OPTION_LIST_ID = 4553158 
    ) AS Location_Conditional_Value, 
    ... 

で、JOINとGROUP BYを取り除きます。

zcoptionsに複数の行がある場合、GROUP BYが不適切に形成されています。クエリは、グループ化されていない列を自由に混在させることができます。あなたのテーブルのエイリアスを作成してください

(SELECT min(CONDITION_VALUE) ... 

または

(SELECT CONDITION_VALUE ... LIMIT 1) as ...,