How @ElementCollection With @OrderColumn Works

Description: This application reveals the performance penalties of using @ElementCollection. In this case, with @OrderColumn. But, as you can see in this application (in comparison with item 33), by adding @OrderColumn can mitigate some performance penalties when operations takes place near the collection tail (e.g., add/remove at/from the end of the collection). Mainly, all elements situated before the adding/removing entry are left untouched, so the performance penalty can be ignored if we affect rows close to the collection tail.

Key points:

• an @ElementCollection doesn't have a primary key
• an @ElementCollection is mapped in a separate table
• prefer @ElementCollection with @OrderColumn when you have a lot of inserts and deletes near the collection tail
• the more elements are inserted/removed from the beginning of the collection the greater the performance penalty will be

Output example:

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