Microsoft Sql Server Table Variable Example In ScienceMicrosoft SQL Server is a relational database management system developed by Microsoft. As a database server, it is a software product with the primary function of. Is it possible to add a metadatalike description or comments to a table in Microsoft SQL 2000 and above How would you do this through the CREATE TABLE statement The main reason why Microsoft introduced table variable in SQL Server 2000 is to reduce stored procedure recompilations a recompilation occurs when the stored. How to schedule and automate backups of SQL Server databases in SQL Server Express. Microsoft Sql Server Table Variable Example In Scientific ExperimentImprovements in Table Variables and Temporary Tables in SQL Server 2. SQL Server 2. 01. TVPs, parallel SELECT INTO, relaxed eager writes and improved cardinality estimates for table variables. The last two improvements were also backported to SQL Server 2. Some of the new features target specifically temporary objects, whereas others are more general and just happen to effect temporary objects as well. The examples in this articles demonstrating the new features use a sample database called Performance. V3. You can find the source code to create this database here http tsql. Performance. V3. After running this script, make sure you set your database context to Performance. V3 T SQL Black Belt 2. Itzik Ben Gan Improvements in Table Variables and Temporary Tables in SQL Server 2. Make sure you have database Performance. V3 installed Installation script http tsql. Performance. V3. USE Performance. V3 GOIn some of the examples I use a helper table function called Get. Nums, which accepts integer inputs called low and high, and returns a sequence of integers in the requested range. Use the code in Listing 1 to create the Get. Nums functions the sample database. IF OBJECTIDNdbo. Get. Nums, NIF IS NOT NULL DROP FUNCTION dbo. Get. Nums GOCREATE FUNCTION dbo. Get. Numslow AS BIGINT, high AS BIGINT RETURNS TABLEASRETURNWITHL0   AS SELECT c FROM SELECT 1 UNION ALL SELECT 1 AS Dc,L1   AS SELECT 1 AS c FROM L0 AS A CROSS JOIN L0 AS B,L2   AS SELECT 1 AS c FROM L1 AS A CROSS JOIN L1 AS B,L3   AS SELECT 1 AS c FROM L2 AS A CROSS JOIN L2 AS B,L4   AS SELECT 1 AS c FROM L3 AS A CROSS JOIN L3 AS B,L5   AS SELECT 1 AS c FROM L4 AS A CROSS JOIN L4 AS B,Nums AS SELECT ROWNUMBER OVERORDER BY SELECT NULL AS rownum. FROM L5SELECT TOPhigh low 1 low rownum 1 AS n. FROM Nums. ORDER BY rownum GOListing 1 Get. Nums helper function Inline Index Definition. Prior to SQL Server 2. Once you declare a table variable, you cannot alter its definition. This meant that if you wanted indexes in your table variables, your only option was to define those indirectly via inline PRIMARY KEY and UNIQUE constraint definitions. You couldnt, for example, define non unique indexes. As you probably know, one of the bigger features added in SQL Server 2. In Memory OLTP engine, with its support for memory optimized tables, hash and BW Tree indexes and natively compiled stored procedures. The initial implementation precludes the ability to alter the definition of a memory optimized table once you created it. This restriction required Microsoft to introduce support for inline index definitions as part of the table creation syntax. Since they already did the work in the parser, Microsoft decided to extend the support for such syntax to also disk based tables, including table variables. Consequently, in SQL Server 2. DECLARE T1 AS TABLEkeycol INT NOT NULLPRIMARY KEY NONCLUSTERED,col. INT NOT NULLINDEX idxclcol. CLUSTERED, column indexcol. INT NOT NULL,col. INT NOT NULL,INDEX idxnccol. NONCLUSTERED col. Just like with column level and table level constraints, you can define column level and table level indexes. You will typically use the former syntax when the index has a single key column as is the case in the above example with the index on col. You have to use the latter syntax when the index is composite, as is the case with the index on col. As you can see, you can indicate whether the index is clustered or nonclustered. SQL Server articles, scripts, and discussion groups. TSQL BlackBelt 201504, Itzik BenGan Improvements in Table Variables and Temporary Tables in SQL Server 2014. Currently, inline indexes do not support the options UNIQUE, INCLUDE and WHERE. The lack of support for the UNIQUE option is no big deal since you can always define a PRIMARY KEY or UNIQUE constraint, which create a unique index underneath the covers. Hopefully, we will see support for the INCLUDE and WHERE options in the future. Memory optimized table types and TVPs. SQL Server 2. 00. TVPs. Prior to SQL Server 2. With SQL Servers support for memory optimized tables and natively compiled stored procedures as part of the In Memory OLTP feature, Microsoft also adds support for memory optimized table types and TVPs. The original thinking was to allow you to declare a table variable of a memory optimized table type, fill it with rows, and pass it as a TVP to a natively compiled procedure. However, nothing prevents you from creating table variables based on memory optimized table types and use those for other purposes, including passing them as TVPs to regular procedures. This way you can leverage the performance benefits of the memory optimized structures and avoid the disk based representation in tempdb. Just bear in mind that in the initial implementation of the In Memory OLTP feature in SQL Server 2. So make sure you do some testing to compare the use of disk based table types and TVPs with memory optimized ones to decide which ones work better for you. To use this feature, you need to add to your database a filegroup for memory optimized data marked as CONTAINS MEMORYOPTIMIZEDDATA and a container pointing to a folder in the file system similar to what you use with the FILESTREAM feature. The parent folder must already exist and the child folder must not exist when you add the container. So before you execute the following code, make sure that the folder C IMOLTP exists and that the folder C IMOLTPPerformance. V3dir doesnt exist or replaced with alternative folder names of your preference ALTER DATABASE Performance. V3. ADD FILEGROUP Performance. V3MO CONTAINS MEMORYOPTIMIZEDDATA GOALTER DATABASE Performance. V3. ADD FILE NAME Performance. V3dir,FILENAME C IMOLTPPerformance. V3dir TO FILEGROUP Performance. V3MO GOTo create a memory optimized table type, add the option MEMORYOPTIMIZED ON to the type definition. As an example, the following code creates a table type called Order. IDs that represents a set of order IDs IF TYPEIDNdbo. Order. IDs IS NOT NULL DROP TYPE dbo. Order. IDs CREATE TYPE dbo. Order. IDs AS TABLEorderid INT NOT NULL PRIMARY KEY NONCLUSTEREDWITH MEMORYOPTIMIZED ON A memory optimized table has to have at least one index to enable access to the rows in memory. It can be either a BW Tree index a lock free, latch free, variation of a B tree index like the one in our example, or a hash one. The former is efficient for range and order based activities. The latter is efficient for point queries. To make the index in our example a hash one, right after the keyword NONCLUSTERED, add HASH WITH BUCKETCOUNT lt count. Microsoft recommends to specify a bucket count that is one to two times the number of distinct values that you expect in the column. With the table type defined, you can now use it as a type for table variables, like so DECLARE My. Order. IDs AS dbo. Order. IDs INSERT  INTO My. Order. IDsorderidVALUES  1. SELECT  FROM    My. Order. IDs As mentioned, you can also use a memory optimized table type as a type for TVPs. As an example, the following code creates a procedure that accepts a parameter called Order. IDs of the Order. IDs type with an input set of order IDs, and returns information about the requested orders IF OBJECTIDNdbo. Get. Orders, NP IS NOT NULL     DROP PROC dbo. Get. Orders GOCREATE PROC dbo. Get. OrdersOrder. IDs AS dbo. Order. IDs READONLY AS SELECT  O.