SSIS containers are defined as a set of logically linked tasks that allows the management of the task scope effectively. Containers allow looping through tasks set until tasks are grouped logically or until specified criteria are met. Nesting of containers is also allowed and the containers are set in the Package designer section in the Control flow tab. The following containers are present in SSIS: Task Host Containers: Default container where all single tasks are available and are used for background scenes in SSIS. This is not present in the toolbox of Visual Studio and is assigned to the task implicitly. This container is also used to extend event handlers and variables. Sequence Containers: These handle the flow of package subset and helps to divide packages into smaller pieces. These are displayed in the Control Flow tab. We can drag and drop containers from the toolbox in the design pane and then add a set of tasks into the container. Following things can be ac...
This transformation will take data from the source and randomly sampling data. It gives you 2 outputs. First is selected data and the second one is unselected data. It is used in a situation where you train a data mining model. These two are used to take the SAMPLE of data from the input data.
There are 3 types of lookup cache modes. These are part of Lookup Transformation in SSIS. Full Cache Mode : This mode helps in querying the database before the data-flow task is executed. This constitutes a critical part of the pre-execution step of the data-flow task. In this mode, the entire data copy is copied from the table and stored into the lookup cache in SSIS. Partial Cache Mode : This mode helps in querying new rows in the database from different data sources. Here, the matched row data is cached into the SSIS lookup cache. If the lookup cache is full, the data is removed automatically from the cache based on the usage statistics of the existing rows to free up space for newly matched rows. No Cache Mode : Here, the data is not cached unless 2 subsequent sources come up with the same matched rows. Database queries are run to get matched data every time from the source.
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