SSIS Task Host Container

What is Task Host Container in SSIS?

1. It’s a default container where every single tasks fall into.
2. If we don’t specify a container then the task will fall into Task Host container.
3. The Task Host is not configured separately, instead, it is configured when we set the properties of the task it encapsulates.
4. SSIS extends variables and event handlers to the task through task host container

By Harsh Shah

MaxConcurrentExecutables property in SSIS Packages

Let’s learn about the MaxConcurrentExecutables property in SSIS

1. It’s a property of Control Flow. The value of the property is an Integer that contains the number of threads that a package can create.
2. Gets or sets the maximum number of threads a package can create.
3. Default value is -1 that means add 2 to the number of processor and use that value to execute the number of tasks in parallel. For example , if server has 2 processors and the default value is specified, SSIS will allow upto 4 tasks to be run parallel.
4. Valid values are 1 or higher and -1
5. It is used when parallelism exists in the workflow or package. If workflow is a series of sequential precedence constraints than this property has no effect.
6. If the number of possible parallel tasks are more than the number of allowable parallel tasks then some of the tasks will have to wait till the parallel threads are available.

Happy Learning !!!

By Harsh Shah

Difference between Control Flow and Data Flow

Let us understand the basic difference between Control Flow and Data Flow in SSIS 2005. 

Control Flow:

1. Process Oriented
2. Doesn’t manage or pass data between components.
3. It functions as a task coordinator
4. In control flow tasks requires completion (Success.,failure or completion)
5. Synchronous in nature, this means, task requires completion before moving to next task. If the tasks are not connected with each other but still they are synchronous in nature.
6. Tasks can be executed both parallel and serially
7. Three types of control flow elements in SSIS 2005
   1. Containers
      • Provides structures in the packages
   2. Tasks
      • Provides functionality in the packages
   3. Precedence Constraints
      • Connects containers, executables and and tasks into an ordered control flow.
      • We can control the sequence execution for tasks and also specify the conditions that tasks and containers run.
8. It is possible to include nested containers as SSIS Architecture supports nesting of the containers. Control flow can include multiple levels of nested containers.

Data Flow

1. Streaming in nature
2. Information oriented
3. Passes data between other components
4. Transformations work together to manage and process data. This means first set of data from the source may be in the final destination step while at the same time other set of data is still flowing. All the transformations are doing work at the same time.
5. Three types of Data Flow components
   1. Sources
      • Extracts data from the various sources (Database, Text Files etc)
   2. Transformations
      • Cleans, modify, merge and summarizes the data
   3. Destination
      • Loads data into destinations like database, files or in memory datasets.

Happy Learning…!!!

By Harsh Shah

SSIS: What is LineageID in SSIS?

LineageID:

• It’s an integer pointer to the column within the buffers
• In Data Flow every column has atleast one LineageID.
• A column can have more than one LineageID. This is because when column passes through various transformation outputs in a Data Flow, it holds the pointer to the column in a buffer in data flow. In the below image you can see the column EmpNo (Sort Input)  has a LineageID: 58

  Image 1: LineageID for the EmpNo column in a Sort Input

Image 2: LineageID for the EmpNo column in a Sort Output is different