Optimizing your DESelect Selections

A poorly constructed selection can lead to time-outs. Multiple factors might cause this including the length and complexity of the Selection, and the volume of data.

In this article, we will provide you with tips and best practices on how DESelect users can optimize their Selections.

Optimization Tips:

• Use a predicate Primary Key on your Data Extensions. This will be a great help when running your Selection that involves combined or joined Data Extensions.
• Use only the necessary fields from Available Data Extensions to your Target Data Extensions instead of selecting all fields. This will lead to less data population.
• Use proper field types. For example, define a text field as a Text data type or a number field using the Number data type. Do not store numbers as text unless you plan to combine or join them with Data Views since they are usually stored as Text data type in SFMC.
• Define Target Data Extension fields' maximum length property based on the maximum size of data to be stored in them. For example, if you always store a five-digit CustomerId then limit the field length to five characters.
• Use correct filter types. For example, instead of selecting multiple fields and use Equals filter type to match multiple values, use an In filter type to select only one field and separate the values using a comma as a separator. Use Equals filters instead of Contains if you can, as Contains leads to slower performance.
• Use as few Data Extensions as possible under Selection Criteria.
• Ensure that the Customer Key length of the Data Extension you are using is within SFMC recommended length (36). To know more about it, refer to this article.

Related articles:

• Optimize the Query Activity.
• Are (NOT) IN/ EXISTS statements followed by a subquery supported in DESelect?