SQL Server 2016 CTP 2.3 update available | download now

September 4, 2015 Leave a comment

Microsoft announced the next update of the recently released Community Technology Preview (CTP) 2.2 version of SQL Server 2016, the CTP 2.3, link.
 

[Register and Download the CTP 2.3 Evaluation version (180 days) here]
 

Direct download link for ISO: SQLServer2016CTP2.3-x64-ENU.iso ~ 2.6 GB
 

–> Enhancements and Issues fixed in this release:

1. Row Level Security support for In-memory OLTP tables, with Natively Compiled UDF support.

2. In-memory DW (Data Warehouse) ColumnStore performance optimizations. NCCI can now be created on tables with triggers, enabled with CDC/Change Tracking

3. Performance improvements to SSAS, including DAX query performance, DirectQuery enhancements, support for variables in DAX.

4. Enhancements to SSRS, including an updated Report Builder with a modern theme and report rendering for modern browsers built on HTML5 standards.

5. Enhancements to SSIS, by releasing oData v4 protocol support, SSIS Error Column support, and advanced logging levels.

6. Improvements to MDS, Many to many derived hierarchy, Excel Add-in Business rule management, and Merge conflicts.

7. Core engine scalability improvement, dynamically partitioning thread safe memory objects by NUMA or CPU, which enables higher scalability of high concurrency workloads running on NUMA hardware.

8. Improvements to the Query Execution with improved diagnostics for memory grant usage.

9. DBCC CHECKDB includes Performance improvement with Persisted computed columns & filtered indexes validation, and Validating a table with thousands of partitions.
 

For all other new features released in SQL Server 2016, please check my blog posts here.
 

So, download the Preview today and start playing with the new features and plan your DB migration/upgrade.
 

Check the [SQL Server blog] for all these updates in detail.
 

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Resolving issues while enabling Temporal Data on an existing Table

August 7, 2015 Leave a comment

In my [previous post] about Temporal Data I showed how to setup Temporal on an existing table. That was a simple scenario where the tables does not have historical data, and we added the 2 Period columns on that table, and we didn’t face any issues.

Check demo to setup Temporal Tables:

TemporalData

There might be other scenarios where an existing table already contains the Period columns and you want to assign them as the Temporal Period Columns. Here, in this post I’ve tried to do the same with an existing table and ran into some issues while setting it up. Resolved the issues in process to make that table a Temporal Table, which we will see below:
 

–> My existing table looks like this, EffectiveStartDate & EffectiveEndDate datetime type columns as Period Columns:

CREATE TABLE dbo.ResourceTD (
	 ResourceID
	 -- other columns here
	,EffectiveStartDate datetime,
	,EffectiveEndDate datetime,
)

 

–> 1. First Issue: While setting up Parent Temporal Table with the ALTER TABLE statement:

ALTER TABLE dbo.ResourceTD 
ADD PERIOD FOR SYSTEM_TIME (
    EffectiveStartDate, 
    EffectiveEndDate
)
GO

… I got following error below:

Msg 13575, Level 16, State 0, Line 42
ADD PERIOD FOR SYSTEM_TIME failed because table ‘SQL2016POC.dbo.ResourceTD’ contains records where end of period is not equal to MAX datetime.

This was evident by the error message, as the columns datatype was datetime initially and I ALTERed them to datetime2 but the values set were not MAX, but like this “9999-12-31 00:00:00”. So, you need to set them to the MAX possible date, like “9999-12-31 23:59:59.9999999” as shown below:

UPDATE dbo.ResourceTD 
SET EffectiveEndDate = '9999-12-31 23:59:59.9999999'
GO

 

–> 2. Second Issue: Finally, while enabling the Temporal Table with History Table:

-- Enabling the System-Versioning ON
ALTER TABLE dbo.ResourceTD 
SET (SYSTEM_VERSIONING = ON (HISTORY_TABLE = dbo.ResourceTDHistory))
GO

… I got following error below:

Msg 13541, Level 16, State 0, Line 85
Setting SYSTEM_VERSIONING to ON failed because history table ‘SQL2016POC.dbo.ResourceTDHistory’ contains invalid records with end of period set before start.

I found that the EffectiveStartDate & EffectiveEndDate columns values were not correct, actually EffectiveStartDate was greater than EffectiveEndDate. That might be due to some previous processing of business logic and manual error. So, I swapped the value for those records.
 

–> You will need to check for all possible scenarios until the Historical Table gets created successfully, some as follows (but not limited to these):


-- Scenario #1
SELECT * FROM ResourceTDHistory WHERE EffectiveStartDate IS NULL
SELECT * FROM ResourceTDHistory WHERE EffectiveEndDate IS NULL

-- Scenario #2
SELECT * 
FROM ResourceTDHistory 
WHERE EffectiveStartDate > EffectiveEndDate

 

I faced these two issues related to this single table. You might face similar or other issues with other tables, based upon different scenarios.

I will update this post if I see any other issues while setting up Temporal tables. Or if you come across, please let me know by your comments, Thanks !!!
 

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Memory Optimized “Table Variables” in SQL Server 2014 and 2016


SQL Server 2014 provided you these new features to create [Memory Optimized Tables] and [Native Compiled Stored Procedures] for efficient and quick processing of data and queries which happens all in memory.

It also provided you one more feature to create Memory Optimized Table Variables, in addition to normal Disk Based Table Variables.

This new feature would provide you more efficiency in Storing, Retrieving and Querying temporary data from and in memory.

Normal Table Variables are created in tempdb and utilize it for their entire life. Now with these new Memory Optimized Table Variables they will become free from tempdb usage, relieve tempdb contention and reside in memory only till the scope i.e. batch of a SQL script or a Stored Procedure.

Let’s see how to use these and what performance gain you get out of these tables.
 

–> Enable Database for supporting Memory Optimized tables: To use this feature your Database should be associated with a FileGroup. So, let’s alter the database.


USE [TestManDB]
GO

-- Add the Database to a new FileGroup

ALTER DATABASE [TestManDB]
    ADD FILEGROUP [TestManFG] CONTAINS MEMORY_OPTIMIZED_DATA 
GO

ALTER DATABASE [TestManDB]
ADD FILE ( 
	NAME = TestManDBFG_file1,
    FILENAME = N'E:\MSSQL\DATA\TestManDBFG_file1' -- Put correct path here
)
TO FILEGROUP TestManFG
GO

Otherwise, while creating Memory Optimized objects you will get below error:

Msg 41337, Level 16, State 100, Line 1
Cannot create memory optimized tables. To create memory optimized tables, the database must have a MEMORY_OPTIMIZED_FILEGROUP that is online and has at least one container.

 

You cannot create a Memory Optimized Table Variable directly with DECLARE @TableVarName AS TABLE (…) statement. First you will need to create a Table Type, then based upon this you can create Tables Variables.

–> Create a Table TYPE [Person_in_mem]

CREATE TYPE dbo.Person_in_mem AS TABLE(
	 BusinessEntityID INT NOT NULL
	,FirstName NVARCHAR(50) NOT NULL
	,LastName NVARCHAR(50) NOT NULL

	INDEX [IX_BusinessEntityID] HASH (BusinessEntityID) 
		WITH ( BUCKET_COUNT = 2000)
)
WITH ( MEMORY_OPTIMIZED = ON )
GO

The Memory Optimized Table Type should have an Index, otherwise you will see an error as mentioned below:

Msg 41327, Level 16, State 7, Line 27
The memory optimized table ‘Person_in_mem’ must have at least one index or a primary key.
Msg 1750, Level 16, State 0, Line 27
Could not create constraint or index. See previous errors.

 

Ok, now as we’ve created this table type, now we can create as many Table Variables based upon this.

–> Now, create a Table variable @PersonInMem of type [Person_in_mem] that is created above:

DECLARE @PersonInMem AS Person_in_mem

-- insert some rows into this In-Memory Table Variable
INSERT INTO @PersonInMem
SELECT TOP 1000
	 [BusinessEntityID]
	,[FirstName]
	,[LastName]
FROM [AdventureWorks2014].[Person].[Person]

SELECT * FROM @PersonInMem
GO

Here we successfully created a Table Variable, inserted records into it and retrieved same by the SELECT statement, and this all happened in memory.
 

Now how can we see we that how much benefits we got from this? What we can do is, we can create a separate Disk-Based Table Variable and do similar operation on it and compare the results by checking the Execution Plan.

–> Comparing performance of both In-Memory vs Disk-Based Table-Variables

– Enable the Actual Execution Plan and run below script to Create and Populate both:

1. In-Memory Table Variable

2, Disk-Based Table Variable

-- 1. In-Memory Table Variable
DECLARE @PersonInMem AS Person_in_mem

INSERT INTO @PersonInMem
SELECT TOP 1000
	 [BusinessEntityID]
	,[FirstName]
	,[LastName]
FROM [AdventureWorks2014].[Person].[Person]

select * from @PersonInMem


-- 2. Disk-Based Table Variable
DECLARE @Person AS TABLE (
	 BusinessEntityID INT NOT NULL
	,FirstName NVARCHAR(50) NOT NULL
	,LastName NVARCHAR(50) NOT NULL
)

INSERT INTO @Person
SELECT TOP 1000
	 [BusinessEntityID]
	,[FirstName]
	,[LastName]
FROM [AdventureWorks2014].[Person].[Person]

select * from @Person
GO

 

–> Now, check the Actual Execution Plan results below:

1. Check the Cost of INSERT operation with both the tables:

– It took only 8% cost to insert into In-memory Table Variable.

– But it took 89% cost to insert into a Disk-Based Table Variable.

> If You see the individual Operators in both the plans you will see that :
For @PersonInMem Table Variable the cost of INSERT was just 19% compared to the cost of INSERT for @Person Table Variable that was 92%.

SQL Server 2016 - Memory Optimized Table Variables 01

2. Check the Cost to SELECT/Retrieve rows both the tables:

– It took only 0% cost to retrieve rows from the In-memory Table Variable

– And it took 3% cost to retrieve rows from a Disk-Based Table Variable

SQL Server 2016 - Memory Optimized Table Variables 02

This proves that the INSERT and SELECT operations with Memory Optimized table are way more faster that normal Disk-Based tables.

Thus, using Memory Optimized Table Variables will provide you better performance for storing temporary data within memory and process with in Stored Procedure or your T-SQL Scripts.
 

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Obfuscate column level data by using “Dynamic Data Masking” in SQL Server 2016


This time SQL Server 2016 has made good additions in area of Security by introducing features like:

1. Always Encrypted

2. Row Level Security, check my previous post,

3. Dynamic Data Masking, this post

4. and other security features, like Transparent Data Encryption (TDE), etc.
 

Dynamic Data Masking provides you support for real-time obfuscation of data so that the data requesters do not get access to unauthorized data. This helps protect sensitive data even when it is not encrypted, and shows obfuscated data at the presentation layer without changing anything at the database level.

Dynamic Data Masking limits sensitive data exposure by masking it to non-privileged users. This feature helps prevent unauthorized access to sensitive data by enabling customers to designate how much of the sensitive data to reveal with minimal impact on the application layer. It’s a Policy-based Security feature that hides the sensitive data in the result set of a Query over designated database columns, while the data in the database is not changed.
 

–> “Dynamic Data Masking” provides you three functions/options to Mask your data:

1. default(): just replaces the column value with ‘XXXX’ by default.

2. email(): shows an email ID to this format ‘aXXX@XXXX.com’.

3. partial(prefix,padding,suffix): gives you option to format and mask only some part of a string value.

We will see the usage of all these 3 masking functions below.
 

–> To setup Dynamic Data Masking on a particular Table you need to:

1. CREATE TABLE with MASKED WITH FUNCTION option at column level.

– Or ALTER TABLE columns by using this option if the table is already present.

2. Create Users and Grant Read/SELECT access for the above CREATED/ALTERED table.
 

–> 1. Create a sample table [dbo].[Customer] with masked columns:

CREATE TABLE dbo.Customer (
	CustomerID 	 INT IDENTITY PRIMARY KEY,
	FirstName 	 VARCHAR(250),
	LastName 	 VARCHAR(250) MASKED WITH (FUNCTION = 'default()') NULL,
	PhoneNumber  VARCHAR(12)  MASKED WITH (FUNCTION = 'partial(1,"XXXXXXXXX",0)') NULL,
	Email 		 VARCHAR(100) MASKED WITH (FUNCTION = 'email()') NULL,
	CreditCardNo VARCHAR(16)  MASKED WITH (FUNCTION = 'partial(4,"XXXXXXXXXX",2)') NULL,
);

–> Now insert some test records (fictitious figures):

INSERT INTO dbo.Customer (FirstName, LastName, PhoneNumber, Email, CreditCardNo)
VALUES
('Manoj',   'Pandey', '4442889882', 'manojp@gmail.com', '4563234576547834'),
('Saurabh', 'Sharma', '9812446452', 'sausha@gmail.com', '1243096778653487'),
('Vivek',   'Singh',  '6745239856', 'viveks@gmail.com', '8756341209876735'),
('Keshav',  'Singh',  '9867452387', 'keshav@gmail.com', '2938713685372618');

–> Let’s check the rows on [dbo].[Customer] table in context of my User:

SELECT * FROM dbo.Customer;
GO

SQLServer2016 - DDM 01

Here, I can see all the row/column values as I have full access to read the masked/sensitive data.
 

–> 2.a. Now let’s create a Test Account and just Grant Read access to [dbo].[Customer] table:

CREATE USER AnyUser WITHOUT LOGIN;
GO

GRANT SELECT ON dbo.Customer TO AnyUser;
GO

–> Let’s execute the SELECT statement on [dbo].[Customer] table in the Context of this new user account:

EXECUTE AS USER = 'AnyUser';
SELECT * FROM dbo.Customer;
REVERT;
GO

SQLServer2016 - DDM 02

And you can see that the user is not able to see the masked data as he is not authorized to see it.
 

–> Removing Masking from a column by simple ALTER TABLE/COLUMN statement:

ALTER TABLE dbo.Customer 
ALTER COLUMN LastName DROP MASKED;
GO

-- Let's check the table data again:
EXECUTE AS USER = 'AnyUser';
SELECT * FROM dbo.Customer;
REVERT;
GO

SQLServer2016 - DDM 03

Here, now you are able to see contents of LastName columns, as the masking has been removed from this column by using simple ALTER TABLE/COLUMN statement.
 

–> 2.b. Granting the UNMASK permission to “AnyUser”:

GRANT UNMASK TO AnyUser;
GO

-- Let's check the table data again:
EXECUTE AS USER = 'AnyUser';
SELECT * FROM dbo.Customer;
REVERT; 
GO

SQLServer2016 - DDM 01

He is able to see all data unmasked when the UNMASK permission is granted to this user.
 

–> 2.c. Revoking back the UNMASK permission form the same user:

REVOKE UNMASK TO AnyUser;
GO
EXECUTE AS USER = 'AnyUser';
SELECT * FROM dbo.Customer;
REVERT; 
GO

After Revoking UNMASK permission he is again not able to see complete data.
 

This way you can control access to your precious or PII data by masking the columns/fields that you don’t want to show to the external world or some set of users.
 

–> Final Cleanup:

DROP TABLE dbo.Customer;
GO
DROP USER [AnyUser]
GO

 

–> Check the same demo on YouTube:

SQL Server - Dynamic Data Masking - YouTube
 

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Configure multiple TempDB Database Files while installing SQL Server 2016 (new feature)


With SQL Server 2016 now you can configure the number of TempDB Database Files during the installation of a new Instance. While installation process in the Database Engine Configuration page you will see an extra option to set number of TempDB files.
 

Or, you can specify the number of files by using the new command line parameter: /SQLTEMPDBFILECOUNT

setup.exe /Q /ACTION="INSTALL" /IACCEPTSQLSERVERLICENSETERMS 
 /FEATURES="SqlEngine" /INSTANCENAME="SQL15" .. 
 /SQLTEMPDBDIR="D:\tempdb" /SQLTEMPDBFILECOUNT="4"

 

While installing via UI the label besides the Input Control below mentions: “The default value is 8 or the number of cores, whichever is lower. This value can be increased up to the number of cores”.

SQL Server 2016 Install 06
 

So, in my [C:\Program Files\Microsoft SQL Server\MSSQL13.SQLSERVER2016\MSSQL\DATA\] folder I could see 8 data files, with 1 log file:

SQL Server 2016 Install 07
 

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