Data Blending

Data blending is used when we use data from more than one data source in a single workbook. Data blending is based on the common dimension used to join both databases. Two data sources used in data blending are referred to as a primary data source and secondary data source. A small chain image appears next to the common dimension between both data sources. Data blending is used to combine data from one data source with column data from another data source in a single table.

Why data blending is useful over join-

1- Data is at different granularity.
2- Data is not supported by cross-database join

Tableau Data Extract

Tableau data extract (.dte) Stores tableau data as a filtered and aggregated extract. TDE files are data extracted from external sources such as MS Access or Excel. It is used for external data.  This data can be text,  numerical, or statistical data. 

TDE extracts are Tableau's method of caching data logically to reduce database hits for frequent access reports. TDE extract can be refreshed manually through the Tableau desktop or can be scheduled for periodic refresh through the enterprise edition.

Tableau Packaged Workbook

Tableau packaged workbook contains the Tableau package and extracted local data. The packaged workbook also includes background picture and customized settings in a workbook.
The main purpose of a packaged workbook is to share it with other Tableau Desktop users, who do not have data access. These users can modify the workbook also.
Tableau Reader user can also use packaged workbook but they can't modify it.

The workbook is not connected to original data source and images. It is saved with a .twbx file extension.

Tableau Workbook

Tableau workbook files have the .twb file extension. It is default file type for Tableau users. It does not contain any data in the file.
Tableau Workbook is in XML format. ( it can be edited in a text editor). A workbook contains one or more worksheets. It can also contain dashboards or stories.
It contains information about all formatting, styles, and aggregations applied to any sheet or dashboards in the workbook.
It also contains information about the data source connection and metadata created due to all connections.
Tableau workbook files can be shared with colleagues and clients but they should have access to the data sources.

Type of Tableau Extension File

Tableau uses different file formats which depend on the purpose of their uses. The various formats have unique file types which are identified by their extensions. These Tableau files can be opened in XML format and edited and modified as required.

1. [.TWB]       Tableau Workbook
2. [.TWBX]    Tableau Packaged Workbook
3. [.TDS]        Tableau Data Source
4. [.TDSX]     Tableau Packaged Data Source
5. [.TDE]        Tableau Data Extract
6. [.TDM]       Tableau Bookmark
7. [.TMS]        Tableau Map Source
8. [.TPS]         Tableau Preference