Overview of Microsoft SSIS
February 27, 2022
This article will take the reader through Microsoft SSIS, a tool for integrating and migrating data in Microsofts SQL server database. It will look at various aspects such as the components, tasks, packages, and operation of this phenomenon.
It will also highlight the advantages, disadvantages, and best practices of SSIS.
Table of contents
- Introduction to Microsoft SSIS
- SSIS components
- SSIS tasks
- SSIS packages
- How Microsoft SSIS works
- Advantages of SSIS
- Disadvantages of SSIS
- SSIS best practices
- Further reading
Introduction to Microsoft SSIS
Microsoft SSIS (SQL Server Integration Services) is a tool developed by the Microsoft Company. It integrates, transforms, and migrates data in Microsoft’s SQL Server database. It may be applied to a wide range of integration activities to upgrade data centers. These include data purification, analysis, and ETL (extraction, transformation, and loading).
Data transformation services, also known as DTS, is an older data management tool offered with SQL Server. DTS has been replaced by SSIS due to advancing technology. The software included the Microsoft SQL Server database, and it was used to change data from conventional databases and formats. XML, flat files, and Microsoft Excel are among the file formats recognized by SSIS. Many businesses use the program as a data management tool.
- Control Flow: Control flow is the main component of the SSIS package. It acts as the brain of SSIS. It assists in arranging the execution sequence for all of its components. Containers and tasks are controlled using priority restrictions inside the components.
- Precedence Constraints: A precedence constraint is an SSIS component that instructs tasks to run in a specific sequence. Thus, it describes the SSIS package’s overall process. It directs the implementation of the two related activities by performing the target tasks according to the outcome of the previous task.
- Tasks: A task is defined as a discrete piece of activity in an SSIS package. It is similar to a programming language’s method or function. Nonetheless, coding approaches are not used in SSIS. Rather, you’ll create and customize surfaces using the drag-and-drop method.
- Containers: The container is a component that organizes tasks into workgroups. It additionally enables you to specify variables and events controllers that should be within the range of that particular container, in addition to providing visual continuity. Some of the types of containers in SSIS include:
Sequence containers: A sequence container enables a user to gather and arrange secondary tasks, perform operations, and allocate logs to the container.
Loop containers: A loop container offers a similar capability as the sequence container, but it additionally allows you to repeat the operations. It is, therefore, predicated on a condition of assessment, such as a looping from one to one hundred.
Foreach loop containers: A loop container also permits looping. Rather than utilizing a conditional expression, the loop is performed across a group of objects. Such files are inside a folder.
- Data Flow: This SSIS tool is mainly used to extort data from the server’s storage, alter it, and write it to a different location. While control flow is the main component of SSIS, data flow is its heart.
- SSIS Packages: The SSIS package is another vital aspect of SSIS. It comprises a set of tasks that run in a logical order. Primary restrictions are used to control the task’s execution sequence. A package can assist a user in saving data to a package catalog database on SQL Server. It can be stored as a .dtsx file, an organized format comparable to reporting services’ .rdl files.
- Parameters: With minor differences, parameters are similar to variables. It is simple to take a parameter out of the packaging. It can be specified as a set of values that are supplied before the package can begin.
The following are the significant tasks included in Integration Services:
- Data flow task: This type of task extracts data, does column-level modifications, and loads data streams.
- Tasks for data preparation: Data preparation tasks copy files and directories. They also download data, execute Internet services, apply commands to XML files, and assess data for purification.
- Tasks for workflow: This workflow tasks connect with other operations to launch packages, applications, and batch files. They are also involved in sending and receiving messages among packages, looking through windows management instrumentation (WMI) data, and waiting for WMI notifications.
- SQL server tasks: SQL server tasks read, replicate, insert, erase, and change objects and data on the servers.
- Scripting Task: Scripting tasks are blank tasks that use scripts to expand package performance.
- Tasks for analysis services: The analysis services tasks generate, alter, destroy, and analyze service objects.
- Maintenance tasks: These tasks perform operational activities like backing up and reducing SQL Server databases, repairing and restructuring indexes, and executing SQL Server Agent jobs.
- Custom tasks: A user may create custom tasks with a .com-compatible programming language. Like visual basic, or just a .NET programming language, such as C#. You may design and enroll a client interface for your customized task in the SSIS designer if you wish to access it from there.
This package consists of a logical grouping of links, control-flow components, data flow units, event controllers, variables, and settings. Setting that a user creates visually or directly with SQL server integration services’ graphics software features. The finished package is then saved to SQL Server, or the SSIS version project can be deployed to the SSIS domain controller. The package is then retrieved, processed, and stored as a unit of tasks.
Contents of a package
Containers and tasks: These are also known as the control flow. When the package starts, a control flow comprises several tasks and containers that operate. Users utilize priority constraints to link the tasks and containers inside a package to determine the sequence or establish the criteria for performing the following action or container inside the package control flow. Inside the package control flow, tasks and containers could be organized and executed continuously as a unit.
Data sources and destinations: These can also be referred to as the data flow. Sources and destinations are involved in extracting and loading data, alterations that alter and expand data. It also contains pathways that connect sources, conversions, and destinations that make up a data flow. A Data Flow task should be included inside the package control flow before adding a data flow. A Data Flow task is an SSIS package component that produces, organizes, and executes data flows. Every Data Flow job in a package gets its replica of the data flow processor.
Connection managers: Usually, a minimum of one connection manager is included inside a package. A connection manager connects between a package and a data source. It specifies the access string for obtaining the data used by the package’s processes, transforms, and event controllers.
Below are examples of additional objects which can be included in packages to give them advanced capabilities or enhance current functionality:
Event handlers: A workflow that operates in response to activities triggered by a package, task, or container is known as an event handler. For instance, whenever a pre-execution event or issue happens, a user can utilize an event handler to assess storage capacity and issue a message to an administrator with the error details.
Configurations: A configuration is a collection of property-value combinations that describe the package’s features and components. It is easy to adjust characteristics without affecting the package by using configurations. The settings data is retrieved when the package is started, altering the contents of features. A configuration, for instance, can change the connectivity of a string.
Logging and log providers: A log is a compilation of data describing a package gathered while running. A log, for instance, can offer the beginning and end times of a package run. On the other side, a log provider specifies the destination and the form in which the package, its containers, and tasks will log operating data.
Variables: There are two types of variables supported by the integration services; system variables and user-defined variables. User-defined variables permit bespoke situations in packages, whereas system variables give essential information regarding package objects at program execution.
Parameters: At the stage of package deployment, integration services parameters enable a user to set values to attributes inside the packages. At the project level, users may design project parameters. They are utilized in routing any external input received by the project to any one of the project’s packages. Package parameters allow users to change how a package runs without altering or re-deploying it.
How Microsoft SSIS works
SSIS is a tool used for two functions: data integration and workflow. The SSIS package is used to perform various data transformations and workflow generation. The SSIS package is made up of three parts: operational data, ETL, and data warehouse. Microsoft SSIS works using these parts.
Operational data is a repository employed when combining data from many sources to execute further operations. It is the location where data is stored for immediate use before being sent to a data storage center for storage, reporting, or preservation.
Extract, transform, and load (ETL)
ETL is an operation that involves extracting data from numerous sources, converting it into meaningful information, and storing it in a data warehouse. Data may be in any format, including XML, flat files, and database files.
It also assures that data in the warehouse is current, correct, of excellent quality, and helpful to its users.
A data warehouse is a unified, comprehensive, and systematic data storage created by merging several sources.
To complete the integration process, SSIS takes the following steps:
Step One: It all begins with a functional data warehouse, a database built to combine data from many sources to perform further actions on it.
Step Two: The extraction, transformation, and loading procedures are then done.
Step Three: The data warehouse collects information from various sources and organizes it for easy accessibility and usage.
Step Four: The data warehouse stores data to combine and handle multiple sources to solve the issues. As a result, it aids with decision-making.
Advantages of SSIS
- SSIS can combine data from multiple sources into a single package. Data sources can include customized or programmed interfaces.
- SSIS uses tricky data to access, such as FTP, HTTP, and analysis services.
- SSIS has features that support transformation as a function.
- Configuration is simpler to manage and package.
- Microsoft Visual Studio and SSIS are closely connected.
- Rather than using Object Linking and Embedding, Database (OLE DB), SSIS uses SQL Server Destination to transfer data into SQL faster.
- Complicated transformations, operations with many steps, combining data from many data sources, and systematic error management are all better with this tool.
- In SSIS, data can be loaded to various destinations simultaneously.
Disadvantages of SSIS
- Management studio must view the package deployment result instead of getting it posted to reporting services.
- If a user has many packages that require to be executed simultaneously, it will cause some trouble. It is because SSIS uses a lot of RAM and interferes with SQL.
- When it comes to CPU allocations, it’s also an issue when a user has many packages to execute simultaneously. The processor allocations among SQL and SSIS must ensure it is conducted correctly; SQL will have the dominant position, and SSIS will operate relatively slow.
SSIS best practices
- Sorting: Sorting is a process that consumes a lot of time in SSIS. Data flows from database tables should be sorted out at the database query level.
- Distributed transaction spanning: An SSIS package’s control flow combines multiple control functions. By the use of the same connection, a user may build up a transaction that spans many jobs. The Connection Manager’s “maintain identical link” attribute should be set to “True” to allow this action.
- Limiting package names: If an SSIS package that has a package name that is longer than one hundred characters is uploaded to the SQL Server, the name is trimmed down to one hundred characters, resulting in an execution error. As a result, package names should not exceed one hundred characters.
- Configuration filter: It is an excellent practice. It utilizes the package name as the configuration filter for all package-specific configuration elements. It’s helpful when there are a lot of packages with different setup options.
In this article, we have gone through an overview of Microsoft SQL Server Integration Services (SSIS).
- We learned the key features of Microsoft SSIS and related terminologies.
- We gained an overview of the components and tasks of this phenomenon.
- We gained a better understanding of how Microsoft SSIS works in data integration and workflow.
- We learned the advantages and disadvantages of using this software.
- We also gained an overview of the best practices of Microsoft SSIS.
Peer Review Contributions by: Onesmus Mbaabu