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我想获取基于 SQL Server 数据库的数据子集，这样我就可以为应用程序运行一些冒烟测试。我的典型工作流程如下，但删除查询需要一个多小时，因为 X、Y 和 Z 中有数亿行。我怎样才能让它更快？为了清楚起见，请在您的答案中使用 T-SQL 代码。

  • 通过为每个表运行以下命令来备份每个表：

    SELECT * INTO BACKUP_SRC_PATIENT FROM [SRC_PATIENT] -- has PK patient_id
SELECT * INTO BACKUP_SRC_X FROM [SRC_X] -- has FK patient_id
SELECT * INTO BACKUP_SRC_Y FROM [SRC_Y] -- has FK patient_id
SELECT * INTO BACKUP_SRC_Z FROM [SRC_Z] -- has FK patient_id

  • 删除除 100 名患者外的所有患者

    DELETE FROM [SRC_PATIENT] 
WHERE [PATIENT_ID_NONNUM] NOT IN 
      (SELECT top 100 [PATIENT_ID] FROM [SRC_PATIENT]
       WHERE BLA = 'BLA')

  • 从 SRC_X、SRC_Y 和 SRC_Z 中删除数据，其中患者 ID 不在 SRC_PATIENT 中

    DELETE FROM [SRC_X] 
WHERE [PATIENT_ID] NOT IN 
      (SELECT [PATIENT_ID] FROM [SRC_PATIENT])

DELETE FROM [SRC_Y] 
WHERE [PATIENT_ID] NOT IN 
      (SELECT [PATIENT_ID] FROM [SRC_PATIENT])

DELETE FROM [SRC_Z] 
WHERE [PATIENT_ID] NOT IN 
      (SELECT [PATIENT_ID] FROM [SRC_PATIENT])
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2 回答 2

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而不是删除除 100 之外的所有行 - 截断表并从备份中复制超过 100 行。

TRUNCATE剪辑表中的所有数据，而不必逐行（或逐页删除，视情况而定）：

TRUNCATE TABLE [SRC_PATIENT]
TRUNCATE TABLE [SRC_X]
TRUNCATE TABLE [SRC_Y]
TRUNCATE TABLE [SRC_Z]

INSERT INTO [SRC_PATIENT]
SELECT TOP 100 * FROM [BACKUP_SRC_PATIENT]
WHERE BLA = 'BLA' 

INSERT INTO [SRC_X]
SELECT * FROM [BACKUP_SRC_X]
WHERE [PATIENT_ID] IN (SELECT [PATIENT_ID] FROM [SRC_PATIENT])

INSERT INTO [SRC_Y]
SELECT * FROM [BACKUP_SRC_Y]
WHERE [PATIENT_ID] IN (SELECT [PATIENT_ID] FROM [SRC_PATIENT])

INSERT INTO [SRC_Z]
SELECT * FROM [BACKUP_SRC_Z]
WHERE [PATIENT_ID] IN (SELECT [PATIENT_ID] FROM [SRC_PATIENT])
于 2013-04-08T18:14:45.513 回答
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使用模式开关，然后将您想要的行拉到非备份表中

您将需要创建一个具有相同元数据的表，但切换几乎是立即发生的。

CREATE TABLE dbo.Backup-Table1
(Col1 int
Col2 int)

ALTER TABLE dbo.Table1
SWITCH TO dbo.Backup-Table1

INSERT INTO dbo.Table1
SELECT TOP 100 *
FROM dbo.Backup-Table1
WHERE Condition = Met
于 2013-04-08T18:16:18.967 回答