在SQL Server

Question

發現重複我試圖找到在SQL Server中找到重複的一個更好的辦法的更快捷的方法。這花了超過20分鐘，只有300多萬條記錄運行結果之前開始顯示內SSMS結果窗口。在墜毀之前又過了22分鐘。

然後SSMS顯示16777216次記錄後，他將這個錯誤：

An error occurred while executing batch. Error message is: Exception of type 'System.OutOfMemoryException' was thrown. 

模式：

ENCOUNTER_NUM - numeric(22,0) 
CONCEPT_CD - varchar(50) 
PROVIDER_ID - varchar(50) 
START_DATE - datetime 
MODIFIER_CD - varchar(100) 
INSTANCE_NUM - numeric(18,0) 


SELECT 
    ROW_NUMBER() OVER (ORDER BY f1.[ENCOUNTER_NUM],f1.[CONCEPT_CD],f1.[PROVIDER_ID],f1.[START_DATE],f1.[MODIFIER_CD],f1.[INSTANCE_NUM]), 
    f1.[ENCOUNTER_NUM], 
    f1.[CONCEPT_CD], 
    f1.[PROVIDER_ID], 
    f1.[START_DATE], 
    f1.[MODIFIER_CD], 
    f1.[INSTANCE_NUM] 
FROM 
    [dbo].[I2B2_OBSERVATION_FACT] f1 
    INNER JOIN [dbo].[I2B2_OBSERVATION_FACT] f2 ON 
     f1.[ENCOUNTER_NUM] = f2.[ENCOUNTER_NUM] 
     AND f1.[CONCEPT_CD] = f2.[CONCEPT_CD] 
     AND f1.[PROVIDER_ID] = f2.[PROVIDER_ID] 
     AND f1.[START_DATE] = f2.[START_DATE] 
     AND f1.[MODIFIER_CD] = f2.[MODIFIER_CD] 
     AND f1.[INSTANCE_NUM] = f2.[INSTANCE_NUM] 

Answer 1

不知道快了多少，這是，但值得一試。

SELECT 
    COUNT(*) AS Dupes, 
    f1.[ENCOUNTER_NUM], 
    f1.[CONCEPT_CD], 
    f1.[PROVIDER_ID], 
    f1.[START_DATE], 
    f1.[MODIFIER_CD], 
    f1.[INSTANCE_NUM] 
FROM 
    [dbo].[I2B2_OBSERVATION_FACT] f1 
GROUP BY 
    f1.[ENCOUNTER_NUM], 
    f1.[CONCEPT_CD], 
    f1.[PROVIDER_ID], 
    f1.[START_DATE], 
    f1.[MODIFIER_CD], 
    f1.[INSTANCE_NUM] 
HAVING 
    COUNT(*) > 1