我有两个结构相似的 UPDATE 查询，但一个的 SQL Server 查询计划显示正在使用的索引，另一个只显示常规表扫描。
以下是查询（根据查询计划，#1 不使用索引，#2 使用）-
UPDATE Payment_Metadata
SET
Payment_Metadata.CommodityCode = 'RAW MATERIALS',
Payment_Metadata.C1 = 'RAW MATERIALS',
Payment_Metadata.C2 = 'INGREDIENTS',
Payment_Metadata.C3 = 'OTHER ',
Payment_Metadata.RuleText = '---',
Payment_Metadata.LastUpdatedIndex = Payment_Metadata.LastUpdatedIndex + 1,
Payment_Metadata.IsExcluded = 0,
Payment_Metadata.LogText = 'Commodity>Raw Materials>Ingredients>Other'
FROM
Payment_Metadata
WHERE
Payment_Metadata.IsProcessed = 0
AND (Payment_Metadata.EnrichedVendor = 'NFL'
OR Payment_Metadata.Vendor_No = 'NFL')
第二个查询使用索引：
UPDATE Payment_Metadata
SET
Payment_Metadata.CommodityCode = 'RAW MATERIALS',
Payment_Metadata.C1 = 'RAW MATERIALS',
Payment_Metadata.C2 = 'INGREDIENTS',
Payment_Metadata.C3 = 'OTHER ',
Payment_Metadata.RuleText = '---',
Payment_Metadata.LastUpdatedIndex = Payment_Metadata.LastUpdatedIndex + 1,
Payment_Metadata.IsExcluded = 0,
Payment_Metadata.LogText = 'Commodity>Raw Materials>Ingredients>Other'
FROM
Payment_Metadata
WHERE Payment_Metadata.IsProcessed = 0
AND (Payment_Metadata.EnrichedVendor = '0202054' OR
Payment_Metadata.Vendor_No = '0202054')
以下是表定义：
CREATE TABLE [dbo].[Payment_Metadata](
[ID] [int] IDENTITY(1,1) NOT NULL,
[Company_Code] [varchar](1024) NULL,
[Comp_Code_Desc] [varchar](1024) NULL,
[Vendor_Acct_Group] [varchar](1024) NULL,
[Vendor_No] [varchar](10) NULL,
[Vendor_Name] [varchar](1024) NULL,
[Vendor_ABN] [varchar](1024) NULL,
[Vendor_PTerm] [varchar](1024) NULL,
[Vendor_PTerm_Desc] [varchar](1024) NULL,
[Purchasing_Group] [varchar](1024) NULL,
[Purchasing_Group_Des] [varchar](1024) NULL,
[PO_DocType] [varchar](1024) NULL,
[PO_DocType_Desc] [varchar](1024) NULL,
[Purchasing_Document] [varchar](1024) NULL,
[PO_Date] [varchar](1024) NULL,
[PO_CreatedBy] [varchar](1024) NULL,
[Plant] [int] NULL,
[Item_Number] [varchar](1024) NULL,
[Material_Number] [varchar](1024) NULL,
[Material_Group] [varchar](7) NULL,
[Material_Group_Desc] [varchar](1024) NULL,
[Account_Assignment] [varchar](32) NULL,
[Acct_Assignment_Desc] [varchar](1024) NULL,
[GL_Account] [varchar](7) NULL,
[GL_Account_Desc] [varchar](1024) NULL,
[PO_Desc] [varchar](64) NULL,
[PO_Quantity] [decimal](10, 2) NULL,
[Order_UOM] [varchar](1024) NULL,
[Order_Price_Unit] [varchar](1024) NULL,
[Invoice_Receipt] [varchar](1024) NULL,
[Invoice_Reference] [varchar](1024) NULL,
[Invoice_Date] [datetime] NOT NULL,
[Invoice_Scan_Date] [datetime] NULL,
[Invoice_Item] [int] NULL,
[Invoice_Amount] [decimal](15, 2) NULL,
[GST] [decimal](10, 2) NOT NULL,
[Invoice_Gross_Amount] [decimal](15, 2) NULL,
[Currency] [varchar](1024) NULL,
[Document_Type] [varchar](1024) NULL,
[Document_Number] [varchar](1024) NULL,
[Document_Date] [datetime] NOT NULL,
[Posting_Date] [datetime] NOT NULL,
[Payment_Term] [varchar](1024) NULL,
[Baseline_Date] [datetime] NOT NULL,
[Due_Date] [datetime] NOT NULL,
[Payment_Document] [varchar](1024) NULL,
[Clearing_Date] [datetime] NOT NULL,
[CommodityCode] [varchar](128) NULL,
[RuleText] [nvarchar](max) NULL,
[IsProcessed] [bit] NOT NULL,
[DataSource] [varchar](5) NULL,
[IsContracted] [bit] NOT NULL,
[IsPreferred] [bit] NOT NULL,
[VendorRiskScore] [varchar](5) NULL,
[EnrichedVendor] [varchar](128) NULL,
[LastUpdatedIndex] [int] NOT NULL,
[LogText] [nvarchar](max) NULL,
[IsExcluded] [bit] NOT NULL,
[C1] [varchar](50) NULL,
[C2] [varchar](50) NULL,
[C3] [varchar](50) NULL,
[OriginalVendor] [varchar](60) NULL,
[AdjustedAmount] [decimal](15, 2) NULL
) ON [PRIMARY]
如您所见，该WHERE子句中唯一的变化是数字与非数字字符的使用（我怀疑这不应该影响查询计划？）
EnrichedVendor 和 Vendor_No 列中的每一列都有一个非聚集索引。
任何帮助，将不胜感激。
更新：包括下面的查询计划，我注意到查询 #1 建议一个索引（绿色）。这可能是答案的解决方案。
