使用具有中等数据量的表提高SQL Server查询性能

Question

I have a table with 6000 records but it could be larger in the future. I have attached screen dump of my current SQL query which takes 12 to 14 seconds to load 6000 rows of data.

There are already indexes on the columns which are queried most commonly

How can I improve query performance or modify query for the same?

CREATE TABLE [dbo].[Item]
  (
     [Srno]          [BIGINT] IDENTITY(1, 1) NOT NULL,
     [ITEMCode]      [BIGINT] NOT NULL,
     [BranchId]      [BIGINT] NOT NULL,
     [ITEM_No]       [VARCHAR](50) NULL,
     [ITEM_Desc]     [VARCHAR](200) NULL,
     [DeptId]        [BIGINT] NULL,
     [CatId]         [BIGINT] NULL,
     [SizeId]        [BIGINT] NULL,
     [CostPrice]     [DECIMAL](18, 3) NULL,
     [SalesPrice]    [DECIMAL](18, 2) NULL,
     [ITEM_InStock]  [BIGINT] NULL,
     [UserId]        [BIGINT] NULL,
     [Active]        [BIT] NOT NULL,
     [IsDeleted]     [BIT] NOT NULL,
     [Quantity]      [INT] NULL,
     [IsFavourite]   [BIT] NULL,
     [IsProductLink] [BIT] NULL,
     CONSTRAINT [PK_Item_1] PRIMARY KEY CLUSTERED ( [ITEMCode] ASC, [BranchId] ASC )WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
  )
ON [PRIMARY]

ALTER TABLE [dbo].[Item]
  WITH CHECK ADD CONSTRAINT [FK_Item_Item] FOREIGN KEY([ITEMCode], [BranchId]) REFERENCES [dbo].[Item] ([ITEMCode], [BranchId])

GO

ALTER TABLE [dbo].[Item]
  CHECK CONSTRAINT [FK_Item_Item]

GO

ALTER TABLE [dbo].[Item]
  ADD CONSTRAINT [DF_Item_ITEM_UnitPrice] DEFAULT ((0)) FOR [CostPrice]

GO

ALTER TABLE [dbo].[Item]
  ADD CONSTRAINT [DF_Item_ITEM_RETAILPRICE] DEFAULT ((0)) FOR [SalesPrice]

GO

ALTER TABLE [dbo].[Item]
  ADD CONSTRAINT [DF_Item_ITEM_InStock] DEFAULT ((0)) FOR [ITEM_InStock]

GO

ALTER TABLE [dbo].[Item]
  ADD CONSTRAINT [DF_Item_Active] DEFAULT ((0)) FOR [Active]

GO

ALTER TABLE [dbo].[Item]
  ADD CONSTRAINT [DF_Item_DelFlag] DEFAULT ((0)) FOR [IsDeleted]

GO 

I have updated query and removed join of Department table but still it takes 10 Seconds

   SELECT Item.ITEMCode                 AS ItemId,
       ISNULL(Item.ITEM_No, '0')     AS ItemNo,
       isnull(Item.Barcode, '')      AS Barcode,
       Item.ITEM_Desc                AS ItemName,
       isnull(item_Imagepath, '')    AS ItemImage,
       0                             AS availableQty,
       Item.SalesPrice               AS Price,
       isnull(Item.TaxApply, 0)      AS isTax,
       Item.TaxType,
       ISNULL(Item.ITM_Type, '0')    AS ITMType,
       Item.Profit_Type              AS ProfitType,
       Item.Profit_Amt               AS ProfitAmt,
       Item.CostPrice,
       ISNULL(Item.ITEM_Remarks, '') AS Remark
FROM   Item      

Answer 1

If it takes 10 seconds to read 6000 (small) records then I can only assume/hope that your connection is introducing a lot of delays here!?!

Could you try the following and see how long this takes?

SET STATISTICS TIME ON

SELECT * INTO #test FROM [Item]

If this runs quickly then I'd go look for ways to speed up your connection between your computer and the Azure severs. (network packet size?)