Four Patterns Of Data Loading

There are two main questions to consider when loading data from a database or other external system:

1. Should I load the data at the start, or when I need it?
2. Once I have the data, should I save it for reuse?

The answers to these questions give you the four patterns of data loading:

1. Lazy Load – Load as needed, don’t reuse
2. Pre-Fetch – Load at the beginning, don’t reuse
3. Read Through Cache – Load as needed, save the results for reuse
4. Pre-Cache – Load all the data at the beginning

Each pattern has pros and cons:

Picking the right, or wrong, pattern for you use case can have major performance and scaling implications.

These are the main questions to ask yourself:

• How often does the data change?
• How important is the performance of the code’s critical path?
• How likely am I to reuse the data?
• How much do I know about the data I need?