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# Union Operator Sample

## About This Sample

The Union operator sample uses a Union operator to interleave trades from a Reuters feed and the Interactive Data PlusFeed (formerly Comstock). The input streams contain schemas with the fields `Symbol`, `PricePS` (per share), `Time`, and `FeedID`.

## Importing This Sample into StreamBase Studio

In StreamBase Studio, import this sample with the following steps:

- From the top-level menu, click File → Load StreamBase Sample.

- Enter `operator` to narrow the list of options.

- Select Operator sample group from the Data Constructs and Operators category.

- Click OK.

StreamBase Studio creates a single project for the operator samples.

## Running This Sample in StreamBase Studio

1. In the Project Explorer view, open the sample you just loaded.

   If you see red marks on a project folder, wait a moment for the project to load its features.

   If the red marks do not resolve themselves after a minute, select the project, right-click, and select Maven → Update Project from the context menu.

2. Open the `src/main/eventflow/com.tibco.sb.sample.operator` folder.

3. Open the `Union.sbapp` file and click the Run button. This opens the SB Test/Debug perspective and starts the module.

4. In the Output Streams view, select the `UnionOut` output stream. No output is displayed at this point, but the dequeuer is prepared to receive output. This view eventually shows the output of the application.

5. In the Manual Input view, select the `ComstockIn` input stream.

6. Enter `amat`, `24`, `1`, and `0` in the `Symbol`, `PricePS`, `Time`, and `FeedID` fields, respectively.

7. Click Send Data, and observe this data appearing in the Output Streams view:

       Symbol=amat, PricePS=24.0, Time=1, FeedID=0

8. Select the `ReutersIn` input stream.

9. Enter `msft`, `40`, `2`, and `1` in the `Symbol`, `PricePS`, `Time`, and `FeedID` fields, respectively.

10. Click Send Data, and observe this data appearing in the Output Streams view:

        Symbol=msft, PricePS=40.0, Time=2, FeedID=1

11. Enter `intc`, `24`, `3`, and `1` in the `Symbol`, `PricePS`, `Time`, and `FeedID` fields, respectively.

12. Click Send Data, and observe this data appearing in the Output Streams view:

        Symbol=intc, PricePS=24.0, Time=3, FeedID=1

13. Select the `ComstockIn` input stream.

14. Enter `amat`, `23`, `4`, and `0` in the `Symbol`, `PricePS`, `Time`, and `FeedID` fields, respectively.

15. Click Send Data, and observe this data appearing in the Output Streams view:

        Symbol=amat, PricePS=23.0, Time=4, FeedID=0

16. Select the ReutersIn input stream.

17. Enter `intc`, `22`, `5`, and `1` in the `Symbol`, `PricePS`, `Time`, and `FeedID` fields, respectively.

18. Click Send Data, and observe this data appearing in the Output Streams view:

        Symbol=intc, PricePS=22.0, Time=5, FeedID=1

    Note that the time in this tuple is before the time in the previous tuple. In other words, the Union operator is agnostic to the order of input tuples. Use a Merge operator if you want to order on a field by using a criterion such as time.

19. When done, press F9 or click the Terminate EventFlow Fragment button.

## Sample Location

When you load the sample into StreamBase Studio, Studio copies the sample project's files to your Studio workspace, which is normally part of your home directory, with full access rights.

### Important

Load this sample in StreamBase Studio, and thereafter use the Studio workspace copy of the sample to run and test it, even when running from the command prompt.

Using the workspace copy of the sample avoids permission problems. The default workspace location for this sample is:

    studio-workspace/sample_operator

See Default Installation Directories for the default location of `studio-workspace` on your system.