Friday 24 December 2010

Development Best Practices

Case
As an external employee I see a lot of SSIS packages at various companies made by a whole bunch of different people. Unfortunately some of those people made Quick & Dirty as a motto in life resulting in hard to read packages. And that's a waste of time for the companies.

Solution
Companies should require both well performing and well documented packages. Here is a list of some basic development Best Practices to achieve clear and manageable packages.


1) No default names and descriptions
Rename all default component names and give them explaining descriptions. This will help other developers that edit your packages. It is also very useful when debugging.
No default names and descriptions


















2) Annotations
Use annotations. This is very useful if the Control Flow or Data Flow isn't self describing (for others).
Use annotations
















3 Group logical work
Use Sequence containers to organize package structures into logical units of work. This makes it easier to identify what the package does. It also helps to control transactions if they are being implemented. * Update: SSIS 2012 has a grouping feature *
Use Sequence Containers

















4 Flow directions
Flows should basically go top-down. This will make your packages more readable.
Design your package Top down















You can use the Auto-format option from SSIS to format your packages
Auto Layout is a good start













5) Disabled Control Flow tasks
Do not use disabled Control Flow tasks in the Quality assurance or Production environment. If you want to conditionally execute a task at runtime use expressions on your precedence constraints. Do not use an expression on the “Disable” property of the task.
Disabled Control Flow Task



















6) Spread large number of packages over serveral Visual Studio Project
You can add more than one projects to your Visual Studio Solution to spread large number of packages. Think about a proper layout. For example a datastaging project and a datawarehouse project.


7) Queries in source and look up components
Don't use too complex queries. Use a readable lay-out and add comments to explain parts of the query. For example:
-- This query does something 
SELECT    a.field1
,         a.field2
,         b.field3
,         b.field4
FROM      table1 as a
LEFT JOIN table2 as b
          on a.field5 = b.field6
WHERE     a.field2 = 'x' -- Comment about x
ORDER BY  a.field1

8) Script Coding Conventions
Use condings conventions when scripting a script task or component. C# and VB.Net both have their own conventions which are widely available on the net.

9) Use naming conventions
Give tasks and transformations a prefix. This makes it easier to read the logging.

10) Use templates
You can create templates for SSIS. Things like logging, configurations and connection managers can be added to these templates.

Let me known if you have items that should be in the list of Development Best Practices!

1 comment:

Please use the SSIS MSDN forum for general SSIS questions that are not about this post. I'm a regular reader of that forum and will gladly answer those questions over there.

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