Explain How You Can Notify The Staff Members About Package Failure?
Either inside the package you could add a Send Mail Task in the event handlers, or you can even set notification in the SQL Agent when the package runs.
How Can An Ssis Package Be Scheduled To Execute At A Defined Time Or At A Defined Interval Per Day?
You can configure a SQL Server Agent Job with a job step type of SQL Server Integration Services Package, the job invokes the dtexec command line utility internally to execute the package. You can run the job (and in turn the SSIS package) on demand or you can create a schedule for a one time need or on a reoccurring basis. Refer to this tip to learn more about it.
How Would You Do Error Handling?
A SSIS package could mainly have two types of errors
a) Procedure Error: Can be handled in Control flow through the precedence control and redirecting the execution flow.
b) Data Error: is handled in DATA FLOW TASK buy redirecting the data flow using Error Output of a component.
How To Pass Property Value At Run Time? How Do You Implement Package Configuration?
A property value like connection string for a Connection Manager can be passed to the pkg using package configurations.Package Configuration provides different options like XML File, Environment Variables, SQL Server Table, Registry Value or Parent package variable.
If You Want To Send Some Data From Access Database To Sql Server Database. What Are Different Component Of Ssis Will You Use?
In the data flow, we will use one OLE DB source, data conversion transformation and one OLE DB destination or SQL server destination. OLE DB source is data source is useful for reading data from Oracle, SQL Server and Access databases. Data Conversion transformation would be needed to remove datatype abnormality since there is difference in datatype between the two databases (Access and SQL Server) mentioned. If our database server is stored on and package is run from same machine, we can use SQL Server destination otherwise we need to use OLE DB destination. The SQL Server destination is the destination that optimizes the SQL Server.
What Is Sql Server Integration Services (ssis)?
SQL Server Integration Services (SSIS) is component of SQL Server 2005 and later versions. SSIS is an enterprise scale ETL (Extraction, Transformation and Load) tool which allows you to develop data integration and workflow solutions. Apart from data integration, SSIS can be used to define workflows to automate updating multi-dimensional cubes and automating maintenance tasks for SQL Server databases.
How Does Ssis Differ From Dts?
SSIS is a successor to DTS (Data Transformation Services) and has been completely re-written from scratch to overcome the limitations of DTS which was available in SQL Server 2000 and earlier versions. A significant improvement is the segregation of the control/work flow from the data flow and the ability to use a buffer/memory oriented architecture for data flows and transformations which improve performance.
What Is The Control Flow?
When you start working with SSIS, you first create a package which is nothing but a collection of tasks or package components. The control flow allows you to order the workflow, so you can ensure tasks/components get executed in the appropriate order.
What Is The Data Flow Engine?
The Data Flow Engine, also called the SSIS pipeline engine, is responsible for managing the flow of data from the source to the destination and performing transformations (lookups, data cleansing etc.). Data flow uses memory oriented architecture, called buffers, during the data flow and transformations which allows it to execute extremely fast. This means the SSIS pipeline engine pulls data from the source, stores it in buffers (in-memory), does the requested transformations in the buffers and writes to the destination. The benefit is that it provides the fastest transformation as it happens in memory and we don't need to stage the data for transformations in most cases.
What Is Execution Tree?
Execution trees demonstrate how package uses buffers and threads. At run time, the data flow engine breaks down Data Flow task operations into execution trees. These execution trees specify how buffers and threads are allocated in the package. Each tree creates a new buffer and may execute on a different thread. When a new buffer is created such as when a partially blocking or blocking transformation is added to the pipeline, additional memory is required to handle the data transformation and each new tree may also give you an additional worker thread.
Difference Between Union All And Merge Join?
a) Merge transformation can accept only two inputs whereas Union all can take more than two inputs
b) Data has to be sorted before Merge Transformation whereas Union all doesn't have any condition like that.
How Would You Restart Package From Previous Failure Point?what Are Checkpoints And How Can We Implement In Ssis?
When a package is configured to use checkpoints, information about package execution is written to a checkpoint file. When the failed package is rerun, the checkpoint file is used to restart the package from the point of failure. If the package runs successfully, the checkpoint file is deleted, and then re-created the next time that the package is run.
Where Are Ssis Package Stored In The Sql Server?
MSDB.sysdtspackages90 stores the actual content and ssydtscategories, sysdtslog90, sysdtspackagefolders90, sysdtspackagelog, sysdtssteplog, and sysdtstasklog do the supporting roles.
Difference Between Asynchronous And Synchronous Transformations?
Asynchronous transformation have different Input and Output buffers and it is up to the component designer in an Async component to provide a column structure to the output buffer and hook up the data from the input.
How To Achieve Parallelism In Ssis?
Parallelism is achieved using MaxConcurrentExecutable property of the package. Its default is -1 and is calculated as number of processors + 2.
How Do You Do Incremental Load?
Fastest way to do incremental load is by using Timestamp column in source table and then storing last ETL timestamp, In ETL process pick all the rows having Timestamp greater than the stored Timestamp so as to pick only new and updated records.
How To Handle Late Arriving Dimension Or Early Arriving Facts.?
Late arriving dimensions sometime get unavoidable 'coz delay or error in Dimension ETL or may be due to logic of ETL. To handle Late Arriving facts, we can create dummy Dimension with natural/business key and keep rest of the attributes as null or default. And as soon as Actual dimension arrives, the dummy dimension is updated with Type 1 change. These are also known as Inferred Dimensions.
A transformation simply means bringing in the data in a desired format. For example you are pulling data from the source and want to ensure only distinct records are written to the destination, so duplicates are removed. Another example is if you have master/reference data and want to pull only related data from the source and hence you need some sort of lookup. There are around 30 transformation tasks available and this can be extended further with custom built tasks if needed.
How Can You Configure Your Ssis Package To Run In 32-bit Mode On 64-bit Machine When Using Some Data Providers Which Are Not Available On The 64-bit Platform?
In order to run an SSIS package in 32-bit mode the SSIS project property Run64BitRuntime needs to be set to "False". The default configuration for this property is "True". This configuration is an instruction to load the 32-bit runtime environment rather than 64-bit, and your packages will still run without any additional changes. The property can be found under SSIS Project Property Pages -> Configuration Properties -> Debugging.
How Is Ssis Runtime Engine Different From The Ssis Dataflow Pipeline Engine?
The SSIS Runtime Engine manages the workflow of the packages during runtime, which means its role is to execute the tasks in a defined sequence. As you know, you can define the sequence using precedence constraints. This engine is also responsible for providing support for event logging, breakpoints in the BIDS designer, package configuration, transactions and connections. The SSIS Runtime engine has been designed to support concurrent/parallel execution of tasks in the package.
The Dataflow Pipeline Engine is responsible for executing the data flow tasks of the package. It creates a dataflow pipeline by allocating in-memory structure for storing data in-transit. This means, the engine pulls data from source, stores it in memory, executes the required transformation in the data stored in memory and finally loads the data to the destination. Like the SSIS runtime engine, the Dataflow pipeline has been designed to do its work in parallel by creating multiple threads and enabling them to run multiple execution trees/units in parallel.
What Is A Task?
A task is very much like a method of any programming language which represents or carries out an individual unit of work. There are broadly two categories of tasks in SSIS, Control Flow tasks and Database Maintenance tasks. All Control Flow tasks are operational in nature except Data Flow tasks. Although there are around 30 control flow tasks which you can use in your package you can also develop your own custom tasks with your choice of .NET programming language.
What Is A Precedence Constraint And What Types Of Precedence Constraint Are There?
Either inside the package you could add a Send Mail Task in the event handlers, or you can even set notification in the SQL Agent when the package runs.
How Can An Ssis Package Be Scheduled To Execute At A Defined Time Or At A Defined Interval Per Day?
You can configure a SQL Server Agent Job with a job step type of SQL Server Integration Services Package, the job invokes the dtexec command line utility internally to execute the package. You can run the job (and in turn the SSIS package) on demand or you can create a schedule for a one time need or on a reoccurring basis. Refer to this tip to learn more about it.
How Would You Do Error Handling?
A SSIS package could mainly have two types of errors
a) Procedure Error: Can be handled in Control flow through the precedence control and redirecting the execution flow.
b) Data Error: is handled in DATA FLOW TASK buy redirecting the data flow using Error Output of a component.
How To Pass Property Value At Run Time? How Do You Implement Package Configuration?
A property value like connection string for a Connection Manager can be passed to the pkg using package configurations.Package Configuration provides different options like XML File, Environment Variables, SQL Server Table, Registry Value or Parent package variable.
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| Nate Frequently Asked SSIS Interview Questions Answers |
If You Want To Send Some Data From Access Database To Sql Server Database. What Are Different Component Of Ssis Will You Use?
In the data flow, we will use one OLE DB source, data conversion transformation and one OLE DB destination or SQL server destination. OLE DB source is data source is useful for reading data from Oracle, SQL Server and Access databases. Data Conversion transformation would be needed to remove datatype abnormality since there is difference in datatype between the two databases (Access and SQL Server) mentioned. If our database server is stored on and package is run from same machine, we can use SQL Server destination otherwise we need to use OLE DB destination. The SQL Server destination is the destination that optimizes the SQL Server.
What Is Sql Server Integration Services (ssis)?
SQL Server Integration Services (SSIS) is component of SQL Server 2005 and later versions. SSIS is an enterprise scale ETL (Extraction, Transformation and Load) tool which allows you to develop data integration and workflow solutions. Apart from data integration, SSIS can be used to define workflows to automate updating multi-dimensional cubes and automating maintenance tasks for SQL Server databases.
How Does Ssis Differ From Dts?
SSIS is a successor to DTS (Data Transformation Services) and has been completely re-written from scratch to overcome the limitations of DTS which was available in SQL Server 2000 and earlier versions. A significant improvement is the segregation of the control/work flow from the data flow and the ability to use a buffer/memory oriented architecture for data flows and transformations which improve performance.
What Is The Control Flow?
When you start working with SSIS, you first create a package which is nothing but a collection of tasks or package components. The control flow allows you to order the workflow, so you can ensure tasks/components get executed in the appropriate order.
What Is The Data Flow Engine?
The Data Flow Engine, also called the SSIS pipeline engine, is responsible for managing the flow of data from the source to the destination and performing transformations (lookups, data cleansing etc.). Data flow uses memory oriented architecture, called buffers, during the data flow and transformations which allows it to execute extremely fast. This means the SSIS pipeline engine pulls data from the source, stores it in buffers (in-memory), does the requested transformations in the buffers and writes to the destination. The benefit is that it provides the fastest transformation as it happens in memory and we don't need to stage the data for transformations in most cases.
What Is Execution Tree?
Execution trees demonstrate how package uses buffers and threads. At run time, the data flow engine breaks down Data Flow task operations into execution trees. These execution trees specify how buffers and threads are allocated in the package. Each tree creates a new buffer and may execute on a different thread. When a new buffer is created such as when a partially blocking or blocking transformation is added to the pipeline, additional memory is required to handle the data transformation and each new tree may also give you an additional worker thread.
Difference Between Union All And Merge Join?
a) Merge transformation can accept only two inputs whereas Union all can take more than two inputs
b) Data has to be sorted before Merge Transformation whereas Union all doesn't have any condition like that.
How Would You Restart Package From Previous Failure Point?what Are Checkpoints And How Can We Implement In Ssis?
When a package is configured to use checkpoints, information about package execution is written to a checkpoint file. When the failed package is rerun, the checkpoint file is used to restart the package from the point of failure. If the package runs successfully, the checkpoint file is deleted, and then re-created the next time that the package is run.
Where Are Ssis Package Stored In The Sql Server?
MSDB.sysdtspackages90 stores the actual content and ssydtscategories, sysdtslog90, sysdtspackagefolders90, sysdtspackagelog, sysdtssteplog, and sysdtstasklog do the supporting roles.
Difference Between Asynchronous And Synchronous Transformations?
Asynchronous transformation have different Input and Output buffers and it is up to the component designer in an Async component to provide a column structure to the output buffer and hook up the data from the input.
How To Achieve Parallelism In Ssis?
Parallelism is achieved using MaxConcurrentExecutable property of the package. Its default is -1 and is calculated as number of processors + 2.
How Do You Do Incremental Load?
Fastest way to do incremental load is by using Timestamp column in source table and then storing last ETL timestamp, In ETL process pick all the rows having Timestamp greater than the stored Timestamp so as to pick only new and updated records.
How To Handle Late Arriving Dimension Or Early Arriving Facts.?
Late arriving dimensions sometime get unavoidable 'coz delay or error in Dimension ETL or may be due to logic of ETL. To handle Late Arriving facts, we can create dummy Dimension with natural/business key and keep rest of the attributes as null or default. And as soon as Actual dimension arrives, the dummy dimension is updated with Type 1 change. These are also known as Inferred Dimensions.
What Is A Transformation?
A transformation simply means bringing in the data in a desired format. For example you are pulling data from the source and want to ensure only distinct records are written to the destination, so duplicates are removed. Another example is if you have master/reference data and want to pull only related data from the source and hence you need some sort of lookup. There are around 30 transformation tasks available and this can be extended further with custom built tasks if needed.
How Can You Configure Your Ssis Package To Run In 32-bit Mode On 64-bit Machine When Using Some Data Providers Which Are Not Available On The 64-bit Platform?
In order to run an SSIS package in 32-bit mode the SSIS project property Run64BitRuntime needs to be set to "False". The default configuration for this property is "True". This configuration is an instruction to load the 32-bit runtime environment rather than 64-bit, and your packages will still run without any additional changes. The property can be found under SSIS Project Property Pages -> Configuration Properties -> Debugging.
How Is Ssis Runtime Engine Different From The Ssis Dataflow Pipeline Engine?
The SSIS Runtime Engine manages the workflow of the packages during runtime, which means its role is to execute the tasks in a defined sequence. As you know, you can define the sequence using precedence constraints. This engine is also responsible for providing support for event logging, breakpoints in the BIDS designer, package configuration, transactions and connections. The SSIS Runtime engine has been designed to support concurrent/parallel execution of tasks in the package.
The Dataflow Pipeline Engine is responsible for executing the data flow tasks of the package. It creates a dataflow pipeline by allocating in-memory structure for storing data in-transit. This means, the engine pulls data from source, stores it in memory, executes the required transformation in the data stored in memory and finally loads the data to the destination. Like the SSIS runtime engine, the Dataflow pipeline has been designed to do its work in parallel by creating multiple threads and enabling them to run multiple execution trees/units in parallel.
What Is A Task?
A task is very much like a method of any programming language which represents or carries out an individual unit of work. There are broadly two categories of tasks in SSIS, Control Flow tasks and Database Maintenance tasks. All Control Flow tasks are operational in nature except Data Flow tasks. Although there are around 30 control flow tasks which you can use in your package you can also develop your own custom tasks with your choice of .NET programming language.
What Is A Precedence Constraint And What Types Of Precedence Constraint Are There?
SSIS allows you to place as many as tasks you want to be placed in control flow. You can connect all these tasks using connectors called Precedence Constraints. Precedence Constraints allow you to define the logical sequence of tasks in the order they should be executed. You can also specify a condition to be evaluated before the next task in the flow is executed.
These are the types of precedence constraints and the condition could be either a constraint, an expression or both Success (next task will be executed only when the last task completed successfully) or Failure (next task will be executed only when the last task failed) or Complete (next task will be executed no matter the last task was completed or failed).
What Is A Container And How Many Types Of Containers Are There?
A container is a logical grouping of tasks which allows you to manage the scope of the tasks together.
These are the types of containers in SSIS
Sequence Container - Used for grouping logically related tasks together
For Loop Container - Used when you want to have repeating flow in package
For Each Loop Container - Used for enumerating each object in a collection; for example a record set or a list of files.
Apart from the above mentioned containers, there is one more container called the Task Host Container which is not visible from the IDE, but every task is contained in it (the default container for all the tasks).
What Are Variables And What Is Variable Scope?
A variable is used to store values. There are basically two types of variables, System Variable (like ErrorCode, ErrorDescription, PackageName etc) whose values you can use but cannot change and User Variable which you create, assign values and read as needed. A variable can hold a value of the data type you have chosen when you defined the variable.
Variables can have a different scope depending on where it was defined. For example you can have package level variables which are accessible to all the tasks in the package and there could also be container level variables which are accessible only to those tasks that are within the container.