Pivot and Unpivot

One thing that I still get confused about writing is pivot queries. I find myself needing to lookup the syntax every time. Basically you use Pivot and Unpivot to change the output of a table. If you would like rows turned into columns you can use pivot and for the opposite you can use unpivot.

One thing to note is the column identifiers in the unpivot clause follow the catalog collation. For SQL Database, the collation is always SQL_Latin_General_CP1_CI_AS. For SQL Server partially contained databases, the collation is always Latin1_General_100_CI_AS_KS_WS_SC. If the column is combined with other columns, then a collate clause (COLLATE DATABASE_DEFAULT) is required to avoid conflicts.

So lets take a basic select statement:

USE AdventureWorks2014 ;  
SELECT DaysToManufacture, AVG(StandardCost) AS AverageCost   
FROM Production.Product  
GROUP BY DaysToManufacture;

This returns the following:

DaysToManufacture AverageCost
----------------- -----------
0                 5.0885
1                 223.88
2                 359.1082
4                 949.4105

To pivot the table you can write this kind of query:

-- Pivot table with one row and five columns  
SELECT 'AverageCost' AS Cost_Sorted_By_Production_Days,   
[0], [1], [2], [3], [4]  
(SELECT DaysToManufacture, StandardCost   
    FROM Production.Product) AS SourceTable  
FOR DaysToManufacture IN ([0], [1], [2], [3], [4])  
) AS PivotTable;  

This returns the following:

Cost_Sorted_By_Production_Days 0           1           2           3           4         
------------------------------ ----------- ----------- ----------- ----------- -----------
AverageCost                    5.0885      223.88      359.1082    NULL        949.4105

As you can see it places the average values of the standard cost into the columns specified 0-4.

Here is an example of an Unpivot query:

-- Create the table and insert values as portrayed in the previous example.  
CREATE TABLE pvt (VendorID int, Emp1 int, Emp2 int,  
    Emp3 int, Emp4 int, Emp5 int);  
INSERT INTO pvt VALUES (1,4,3,5,4,4);  
INSERT INTO pvt VALUES (2,4,1,5,5,5);  
INSERT INTO pvt VALUES (3,4,3,5,4,4);  
INSERT INTO pvt VALUES (4,4,2,5,5,4);  
INSERT INTO pvt VALUES (5,5,1,5,5,5);  
-- Unpivot the table.  
SELECT VendorID, Employee, Orders  
   (SELECT VendorID, Emp1, Emp2, Emp3, Emp4, Emp5  
   FROM pvt) p  
   (Orders FOR Employee IN   
      (Emp1, Emp2, Emp3, Emp4, Emp5)  
)AS unpvt;  

Here is a part of the result set:

VendorID    Employee    Orders
----------- ----------- ------
1            Emp1       4
1            Emp2       3 
1            Emp3       5
1            Emp4       4
1            Emp5       4
2            Emp1       4
2            Emp2       1
2            Emp3       5
2            Emp4       5
2            Emp5       5

Remember that unpivot is not the exact reverse of a pivot query. The pivot query uses aggregations and therefore merges possible multiple rows into a single row in the output.

Hope this helps you with your pivot queries!

Merge Statements

Over the years I have come across a lot of merge statements and I find most of the time there is one fundamental flaw in how it is written by most people.

In the update section in most cases I find that there is no section there to check if anything has changed against the target from the source, therefore everything gets updated each and every single time. Whereas if there was this section then only the records that changed would be updated. This saves a lot of time on performance of the query.

Here is an example of a merge that checks if something is changed between source and target before updating the record:

MERGE dbo.DimEmployee	TRG
USING Staging.Employee	SRC ON TRG.EmployeeID = SRC.EmployeeID
	      ISNULL(SRC.FirstName,'Unknown')	 != ISNULL(TRG.FirstName,'Unknown')
       OR ISNULL(SRC.LastName,'Unknown')	 != ISNULL(TRG.LastName,'Unknown')
       OR ISNULL(SRC.MiddleName,'Unknown')	 != ISNULL(TRG.MiddleName,'Unknown')
       OR ISNULL(SRC.NameStyle,'Unknown')	 != ISNULL(TRG.NameStyle,'Unknown')
       OR ISNULL(SRC.Title,'Unknown')		 != ISNULL(TRG.Title,'Unknown')
	TRG.FirstName  = SRC.FirstName
    ,TRG.LastName   = SRC.LastName
    ,TRG.MiddleName = SRC.MiddleName
    ,TRG.NameStyle  = SRC.NameStyle
    ,TRG.Title	   = SRC.Title


Hope this helps you improve the performance of you MERGE statements.

Querying Data in Temporal Tables

Following on from my previous post about modifying data in a temporal table, I will be looking into querying the data in this post.

When you want to get latest (actual) state of data in a temporal table, you can query the same way as you query a normal table. If the PERIOD columns are not hidden, their values will appear in a SELECT * query. If you specified PERIOD columns as hidden, their values won’t appear in a SELECT * query. When the PERIOD columns are hidden, reference the PERIOD columns specifically in the SELECT clause to return the values for these columns.

To perform any type of time-based analysis, use the new FOR SYSTEM_TIME clause with four temporal-specific sub-clauses to query data across the current and history tables.

  • AS OF <date_time>
  • FROM <start_date_time> TO <end_date_time>
  • BETWEEN <start_date_time> AND <end_date_time>
  • CONTAINED IN (<start_date_time> , <end_date_time>)
  • ALL

FOR SYSTEM_TIME can be specified independently for each table in a query. It can be used inside common table expressions, table-valued functions and stored procedures.

Using The AS OF Sub-Clause:
Use the AS OF sub-clause when you need to reconstruct state of data as it was at any specific time in the past. You can reconstruct the data with the precision of datetime2 datatype that was specified in the PERIOD column definitions.

The AS OF sub-clause clause can be used with constant literals or with variables, which allows you to dynamically specify time condition. The provided values are interpreted as UTC time.

This example returns the state of the dbo.Department table AS OF a specific date in the past.

/*State of entire table AS OF specific date in the past*/   
SELECT [DeptID], [DeptName], [SysStartTime],[SysEndTime]   
FROM [dbo].[Department]   
FOR SYSTEM_TIME AS OF '2018-07-01 T10:00:00.7230011' ; 

This example compares the values between two points in time for a subset of rows.

DECLARE @ADayAgo datetime2   
SET @ADayAgo = DATEADD (day, -1, sysutcdatetime())   

/*Comparison between two points in time for subset of rows*/   
SELECT D_1_Ago.[DeptID], D.[DeptID],   
D_1_Ago.[DeptName], D.[DeptName],   
D_1_Ago.[SysStartTime], D.[SysStartTime],   
D_1_Ago.[SysEndTime], D.[SysEndTime]   
FROM [dbo].[Department] FOR SYSTEM_TIME AS OF @ADayAgo AS D_1_Ago   
JOIN [Department] AS D ON  D_1_Ago.[DeptID] = [D].[DeptID]    
AND D_1_Ago.[DeptID] BETWEEN 1 and 5 ;  

Using Views With AS-OF Sub-Clause:
Using views is very useful in scenarios when complex point-in time analysis is required. A common example is generating a business report today with the values for previous month. Usually, customers have a normalized database model which involves many tables with foreign key relationships.

Answering the question how data from that normalized model looked like at a point in the past can be very challenging, since all tables change independently. In this case, the best option is to create a view and apply the AS OF sub-clause to the entire view.

Using this approach allows you to decouple modeling of the data access layer from point-in time analysis as SQL Server will apply AS OF clause transparently to all temporal tables that participate in the view definition.

Furthermore, you can combine temporal with non-temporal tables in the same view and AS OF will be applied only to temporal ones. If the view does not reference at least one temporal table, applying temporal querying clauses to it will fail with an error.

/* Create view that joins three temporal tables: Department, CompanyLocation, LocationDepartments */   
CREATE VIEW [dbo].[vw_GetOrgChart]   
   , [CompanyLocation].LocName  
   , [CompanyLocation].City  
   , [Department].DeptID  
   , [Department].DeptName    
FROM [dbo].[CompanyLocation]   
LEFT JOIN [dbo].[LocationDepartments]    
   ON [CompanyLocation].LocID = LocationDepartments.LocID   
LEFT JOIN [dbo].[Department]    
   ON LocationDepartments.DeptID = [Department].DeptID ;  
/* Querying view AS OF */   
SELECT * FROM [vw_GetOrgChart]   
FOR SYSTEM_TIME AS OF '2018-09-01 T10:00:00.7230011' ;  

Query For Changes To Specific Rows Over Time:
The temporal sub-clauses FROM…TO, BETWEEN…AND and CONTAINED IN are useful when you want to perform a data audit.

The first two sub-clauses return row versions that overlap with a specified period (i.e. those that started before given period and ended after it), while CONTAINED IN returns only those that existed within the specified period boundaries.

If you search for non-current row versions only, I recommend you use CONTAINED IN as it works only with the history table and will yield the best query performance. Use ALL when you need to query current and historical data without any restrictions.

/* Query using BETWEEN...AND sub-clause*/  
   , [DeptName]  
   , [SysStartTime]  
   , [SysEndTime]  
   , IIF (YEAR(SysEndTime) = 9999, 1, 0) AS IsActual   
FROM [dbo].[Department]   
FOR SYSTEM_TIME BETWEEN  '2018-01-01' AND '2018-12-31'   
WHERE DeptId = 1   
ORDER BY SysStartTime DESC;   

/*  Query using CONTAINED IN sub-clause */  
SELECT [DeptID], [DeptName], [SysStartTime],[SysEndTime]   
FROM [dbo].[Department]   
FOR SYSTEM_TIME CONTAINED IN ('2018-04-01', '2018-09-25')   
WHERE DeptId = 1   
ORDER BY SysStartTime DESC ;  

/*  Query using ALL sub-clause */   
   , [DeptName]   
   , [SysStartTime]   
   , [SysEndTime]   
   , IIF (YEAR(SysEndTime) = 9999, 1, 0) AS IsActual    
FROM [dbo].[Department] FOR SYSTEM_TIME ALL   
ORDER BY [DeptID], [SysStartTime] Desc  

Hope you have enjoyed the 3 part series on Temporal Tables.

Modifying Temporal Tables

Following on from my previous post about Temporal Tables, this post talks about modifying temporal tables.

Data in a temporal table is modified using regular DML statements with one important difference: the period column data cannot be directly modified. When data is updated, it is versioned, with the previous version of each updated row and is inserted into the history table. When data is deleted, the delete is logical, with the row moved into the history table from the current table – it is not permanently deleted.

Inserting Data:
When you insert new data, you need to account for the PERIOD columns.

If you specify the column list in your INSERT statement, you can omit the PERIOD columns because the system will generate values for these columns automatically.

--Insert with column list and without period columns   
INSERT INTO [dbo].[Department] ([DeptID] ,[DeptName] ,[ManagerID] ,[ParentDeptID])   
VALUES(10, 'Marketing', 101, 1);

If you do specify the PERIOD columns in the column list in your INSERT statement, then you need to specify DEFAULT as their value.

INSERT INTO [dbo].[Department] ([DeptID] ,[DeptName] ,[ManagerID] ,[ParentDeptID], SysStartTime, SysEndTime)   
VALUES(11, 'Sales', 101, 1, default, default);  

If you do not specify the column list in your INSERT statement, specify DEFAULT for the PERIOD columns.

--Insert without  column list and DEFAULT values for period columns   
INSERT INTO [dbo].[Department]    
VALUES(12, 'Production', 101, 1, default, default);

If PERIOD columns are specified as HIDDEN, then you need only to specify the values for the visible columns when you use INSERT without specifying the column list. You do not need to account for the new PERIOD columns in your INSERT statement. This behavior guarantees that your legacy applications will continue to work when you enable system-versioning on tables that will benefit from versioning.

CREATE TABLE [dbo].[CompanyLocation]  
   , [LocName] [varchar](50) NOT NULL  
   , [City] [varchar](50) NOT NULL  
   , [SysStartTime] [datetime2](0) GENERATED ALWAYS AS ROW START HIDDEN NOT NULL   
   , [SysEndTime] [datetime2](0) GENERATED ALWAYS AS ROW END HIDDEN NOT NULL   
   , PERIOD FOR SYSTEM_TIME ([SysStartTime], [SysEndTime])   
INSERT INTO [dbo].[CompanyLocation]   
VALUES  ('Headquarters', 'New York');

If the current table is partitioned, you can use partition switch as an efficient mechanism to load data into an empty partition or to load into multiple partitions in parallel. The staging table that is used in the PARTITION SWITCH IN statement with a system-versioned temporal table must have SYSTEM_TIME PERIOD defined, but it does not need to be a system-versioned temporal table. This ensures that temporal consistency checks are performed during the data insert into a staging table or when SYSTEM_TIME period is added to a pre-populated staging table.

/*Create staging table with period definition for SWITCH IN temporal table*/   
CREATE TABLE [dbo].[Staging_Department_Partition2]  
     [DeptID] [int] NOT NULL  
   , [DeptName] [varchar](50)  NOT NULL  
   , [ManagerID] [int] NULL  
   , [ParentDeptID] [int] NULL  
   , [SysStartTime] [datetime2](7) GENERATED ALWAYS AS ROW START NOT NULL  
   , [SysEndTime] [datetime2](7) GENERATED ALWAYS AS ROW END NOT NULL  
   , PERIOD FOR SYSTEM_TIME ( [SysStartTime], [SysEndTime] )   

/*Create aligned primary key*/   
ALTER TABLE [dbo].[Staging_Department_Partition2]    
ADD CONSTRAINT [Staging_Department_Partition2_PK]  
   (  [DeptID] ASC )     
   ON [PRIMARY]   

/*Create and enforce constraints for partition boundaries.   
Partition 2 contains rows with DeptID > 100 and DeptID <=200*/ 
ALTER TABLE [dbo].[Staging_Department_Partition2] WITH CHECK ADD CONSTRAINT [chk_staging_Department_partition_2] CHECK ([DeptID]>N'100' AND [DeptID]<=N'200')   
ALTER TABLE [dbo].[Staging_Department_Partition2]    
   CHECK CONSTRAINT [chk_staging_Department_partition_2]   

/*Load data into staging table*/   
INSERT INTO [dbo].[staging_Department] ([DeptID],[DeptName],[ManagerID],[ParentDeptID])   
VALUES (101,'D101',1,NULL)  

/*Use PARTITION SWITCH IN to efficiently add data to current table */    
ALTER TABLE [Staging_Department]    
SWITCH TO [dbo].[Department] PARTITION 2;  

Updating Data:
You update data in the current table with a regular UPDATE statement. You can update data in the current table from the history table to for the “oops” scenario. However, you cannot update PERIOD columns and you cannot directly updated data in the history table while SYSTEM_VERSIONING = ON. Set SYSTEM_VERSIONING = OFF and update rows from current and history table but keep in mind that way system will not preserve history of changes.

UPDATE [dbo].[Department] SET [ManagerID] = 501 WHERE [DeptID] = 10  

You cannot update a PERIOD column and you cannot update the history table. In this example, an attempt to update a PERIOD column generates an error.

UPDATE [dbo].[Department]    
SET SysStartTime = '2015-09-23 23:48:31.2990175'    
WHERE DeptID = 10 ;  

Msg 13537, Level 16, State 1, Line 3   
Cannot update GENERATED ALWAYS columns in table 'TmpDev.dbo.Department'.  

You can use UPDATE on the current table to revert the actual row state to valid state at a specific point in time in the past (reverting to a “last good known row version”). The following example shows reverting to the values in the history table as of 2018-04-25 where the DeptID = 10.

UPDATE Department   
SET DeptName = History.DeptName   
FROM Department    
FOR SYSTEM_TIME AS OF '2018-04-25' AS History   
WHERE History.DeptID  = 10   
AND Department.DeptID = 10 ; 

Deleting Data:
You delete data in the current table with a regular DELETE statement. The end period column for deleted rows will be populated with the begin time of underlying transaction.
You cannot directly delete rows from history table while SYSTEM_VERSIONING = ON.

Set SYSTEM_VERSIONING = OFF and delete rows from current and history table but keep in mind that way system will not preserve history of changes. TRUNCATE, SWITCH PARTITION OUT of current table and SWITCH PARTITION IN history table are not supported while SYSTEM_VERSIONING = ON.

Using A Merge Statement:
MERGE operation is supported with the same limitations that INSERT and UPDATE statements have regarding PERIOD columns.

CREATE TABLE DepartmentStaging (DeptId INT, DeptName varchar(50));   
INSERT INTO DepartmentStaging VALUES (1, 'Company Management');   
INSERT INTO DepartmentStaging VALUES (10, 'Science & Research');   
INSERT INTO DepartmentStaging VALUES (15, 'Process Management');   

MERGE dbo.Department AS target   
USING (SELECT DeptId, DeptName FROM DepartmentStaging) AS source (DeptId, DeptName)   
ON (target.DeptId = source.DeptId)   
   SET DeptName = source.DeptName   
   INSERT (DeptName)   
   VALUES (source.DeptName);  

Temporal Tables

Let’s start off with what is a temporal table? SQL Server 2016 introduced support for system-versioned temporal tables as a database feature that brings built-in support for providing information about data stored in the table at any point in time rather than only the data that is correct at the current moment in time.

A system-versioned temporal table is a type of user table designed to keep a full history of data changes and allow easy point in time analysis. This type of temporal table is referred to as a system-versioned temporal table because the period of validity for each row is managed by the system.

Every temporal table has two explicitly defined columns, each with a datetime2 data type. These columns are referred to as period columns. These period columns are used exclusively by the system to record period of validity for each row whenever a row is modified. A temporal table also contains a reference to another table with a mirrored schema. The system uses this table to automatically store the previous version of the row each time a row in the temporal table gets updated or deleted. This additional table is referred to as the history table, while the main table that stores current (actual) row versions is referred to as the current table or simply as the temporal table.

Benefits of using a temporal table:

  • Auditing all data changes and performing data forensics when necessary
  • Reconstructing state of the data as of any time in the past
  • Calculating trends over time
  • Maintaining a slowly changing dimension for decision support applications
  • Recovering from accidental data changes and application errors

Basic overview of temporal tables:

How does a temporal table work?
A current table and a history table are created, both with two datetime2 columns.

  • Period start column: The system records the start time for the row in this column, typically denoted as the SysStartTime column.
  • Period end column: The system records the end time for the row in this column, typically denoted at the SysEndTime column.

The current table contains the current value for each row. The history table contains each previous value for each row, if any, and the start time and end time for the period for which it was valid.

To create a temporal table you add WITH (SYSTEM_VERSIONING = ON (HISTORY_TABLE = dbo.EmployeeHistory)) at the end of the create statement as below:

CREATE TABLE dbo.Employee   
  , [Name] nvarchar(100) NOT NULL  
  , [Position] varchar(100) NOT NULL   
  , [Department] varchar(100) NOT NULL  
  , [Address] nvarchar(1024) NOT NULL  
  , [AnnualSalary] decimal (10,2) NOT NULL  
  , [ValidFrom] datetime2 (2) GENERATED ALWAYS AS ROW START  
  , [ValidTo] datetime2 (2) GENERATED ALWAYS AS ROW END  
  , PERIOD FOR SYSTEM_TIME (ValidFrom, ValidTo)  

How to query temporal tables:
The SELECT statement FROM clause has a new clause FOR SYSTEM_TIME with five temporal-specific sub-clauses to query data across the current and history tables. This new SELECT statement syntax is supported directly on a single table, propagated through multiple joins, and through views on top of multiple temporal tables.The following query searches for row versions for Employee row with EmployeeID = 1000 that were active at least for a portion of period between 1st January of 2014 and 1st January 2015 (including the upper boundary):

SELECT * FROM Employee FOR SYSTEM_TIME BETWEEN '2017-01-01 00:00:00.0000000' AND '2018-01-01 00:00:00.0000000' WHERE EmployeeID = 1000 ORDER BY ValidFrom;

In the next post we will focus on working with temporal tables.

Original post

SQL Transactions

Transactions in SQL Server are very useful, however I have come across that not many people use them. Not sure why this could be, so thought I would share how transactions work and the different modes.

A transaction is a single unit of work. If a transaction is successful, all of the data modifications made during the transaction are committed and become a permanent part of the database. If a transaction encounters errors and must be canceled or rolled back, then all of the data modifications are erased.

SQL Server operates in the following transaction modes:
Autocommit transactions
Each individual statement is a transaction.

Explicit transactions
Each transaction is explicitly started with the BEGIN TRANSACTION statement and explicitly ended with a COMMIT or ROLLBACK statement.

Implicit transactions
A new transaction is implicitly started when the prior transaction completes, but each transaction is explicitly completed with a COMMIT or ROLLBACK statement.

Batch-scoped transactions
Applicable only to multiple active result sets (MARS), a Transact-SQL explicit or implicit transaction that starts under a MARS session becomes a batch-scoped transaction. A batch-scoped transaction that is not committed or rolled back when a batch completes is automatically rolled back by SQL Server.

From my experience Explicit transactions are the most commonly used out of all the different modes.

Distributed Transactions:
You can use Distributed transactions which specifies the start of a SQL distributed transaction managed by Microsoft Distributed Transaction Coordinator (MS DTC). This is only applicable to SQL Server and no Azure. Transaction-level snapshot isolation does not support distributed transactions.

Is a user-defined transaction name used to track the distributed transaction within MS DTC utilities. transaction_name must conform to the rules for identifiers and must be <= 32 characters.

Is the name of a user-defined variable containing a transaction name used to track the distributed transaction within MS DTC utilities. The variable must be declared with a char, varchar, nchar, or nvarchar data type.

The instance of the SQL Server Database Engine executing the BEGIN DISTRIBUTED TRANSACTION statement is the transaction originator and controls the completion of the transaction. When a subsequent COMMIT TRANSACTION or ROLLBACK TRANSACTION statement is issued for the session, the controlling instance requests that MS DTC manage the completion of the distributed transaction across all of the instances involved.

For example, if BEGIN DISTRIBUTED TRANSACTION is issued on ServerA, the session calls a stored procedure on ServerB and another stored procedure on ServerC. The stored procedure on ServerC executes a distributed query against ServerD, and then all four computers are involved in the distributed transaction. The instance of the Database Engine on ServerA is the originating controlling instance for the transaction.

USE AdventureWorks2012;  
-- Delete candidate from local instance.  
DELETE AdventureWorks2012.HumanResources.JobCandidate  
    WHERE JobCandidateID = 13;  
-- Delete candidate from remote instance.  
DELETE RemoteServer.AdventureWorks2012.HumanResources.JobCandidate  
    WHERE JobCandidateID = 13;  

Begin Transaction
Marks the starting point of an explicit, local transaction. Explicit transactions start with the BEGIN TRANSACTION statement and end with the COMMIT or ROLLBACK statement. BEGIN TRANSACTION increments @@TRANCOUNT by 1.

BEGIN TRANSACTION represents a point at which the data referenced by a connection is logically and physically consistent. If errors are encountered, all data modifications made after the BEGIN TRANSACTION can be rolled back to return the data to this known state of consistency. Each transaction lasts until either it completes without errors and COMMIT TRANSACTION is issued to make the modifications a permanent part of the database, or errors are encountered and all modifications are erased with a ROLLBACK TRANSACTION statement.

Although BEGIN TRANSACTION starts a local transaction, it is not recorded in the transaction log until the application subsequently performs an action that must be recorded in the log, such as executing an INSERT, UPDATE, or DELETE statement.

Naming multiple transactions in a series of nested transactions with a transaction name has little effect on the transaction. Only the first (outermost) transaction name is registered with the system. A rollback to any other name (other than a valid save point name) generates an error. None of the statements executed before the rollback is, in fact, rolled back at the time this error occurs. The statements are rolled back only when the outer transaction is rolled back.

	DELETE	FROM HumanResources.JobCandidate
	WHERE	JobCandidateID = 13

Hope this helps you in future when using transactions. If you are doing INSERTS, UPDATES and DELETES it is advisable that you use a transaction.

Execute SFTP Task in SSIS

Sometimes you need to automate the upload of a file to an FTP or SFTP. Thought I would share the way that I use the SFTP task in SSIS to upload files.

Firstly create the variables to use in the SFTP task. Variables are an easier way to manage things without going into the task, so you can change the password in the variable and not have to open up the SFTP task.

Next you need to complete the SFTP Task Editor.

What you need to take note of above that is very important is that you must remember to place the Remote File name. So this would be the name of the file you are uploading. Once the above is filled in you can click ok and your SFTP task should be ready to go without any red cross on it.

My ETL consists of generating a file to upload, then uploading the file and then sending a mail to notify users the files have been uploaded.

Hope this helps you with using the SFTP task in SSIS.


MDS 2016 Permissions Setup

Following on from a previous post of how to set up Master Data Services (MDS) with IIS, this post is about setting up permissions in MDS 2016.

In previous releases, you had to choose a Windows account during the installation and configuration of the MDS database. This account would become a system-wide administrator and have access to all models. The problem is sometimes system administrators chose their own account instead of a service account. If that person leaves the company, it could break the MDS installation if the account becomes invalid. Correcting this was not easy; it requires lots of manual changes in the MDS database. In SQL Server 2016, you still have to configure such an account.

However, you can now assign users to a new role called Super User. Users assigned to this role will have administrator access to all models. This allows is to mitigate the problem with the super user assigned during configuration of MDS. Furthermore, it also allows you to create multiple super users, which can be useful when maintenance is done by a team of administrators. You can assign users to this role in the Functions tab in the editing screen of a user in the User and Group Permissions section of MDS.

Aside from the Super User Role, some permission sets have been explicitly defined. For example, when a user had update permission on a model in a previous release – and no other permissions in the subtree below the model – the user would become a model administrator. However, if at a later point in time the user gets another explicit permission assigned in the model sub tree (for example on an entity), the user would lose model administrator permissions. Now you can explicitly assign the model administrator role to a user. Any permissions assigned on a lower level are ignored.

The same is true for entity administrators: you can now assign explicit entity administrator privileges to a user.

To recap, there are three administrator roles:

  • Super User – Access to all models and functional areas.
  • Model Administrator – If has access to explorer, the user can modify all master data. If access to system administration, the user can perform all administrative tasks on the model.
  • Entity Administrator – If has access to explorer, the user can modify all data of the entity. The user can also approve or reject change sets for the entity.

Note that making a user a Model Administrator on all the models is not the same as having the Super User permissions. A Super User has access to all the functional areas, while a Model Administrator needs explicit access to a functional area. For example, if a Model Administrator doesn’t have access to the System Administration functional area, he/she cannot create new entities.

In previous versions, you could only assign two permissions on a model object: read-only or update. With MDS 2016, you can now assign the following permissions: readcreateupdatedelete or deny.

If you want to assign a user all permissions (read + create + update + delete) you can choose the shortcut for All permissions. In the tree view, indicators are used to show which permissions a user has for an entity. On the right, you can view a summary of all permissions.

If you assign a user create, update or delete to an entity, the user automatically gets the read permission assigned as well.

Original Article here.

Using a ZIP Task in SSIS

The ZIP file task is a great feature that SSIS has for when you need to move/email a large amount of data. Also if you have multiple files you want to move to the same location, this makes it easier for you, so you can move just one file instead of many.

I prefer to use variables which I can change if the location changes over using hard-coded values. The first step is to create the variables on the package:

Next step is to place the Zip task in your Control Flow area. Then configure it as follows:

This will then compress and zip your files in the source you set. You can then use a Process System task to move this file to where you require it or use an email task to email the file to people.