TYPO3 Core

small update: transient properties of the same simple and Domain types could be saved to, so you could add transient properties like a rendered URL, a image thumbnail etc. to that cached entitiy and your application would even be faster. Especially image processing and link generation have bad performance and should make use of some kind of prefilled cache.

You can use the caching framework to use an own cache in your controller. Should less than 20 lines of code.

Then you can save and retrieve the objects that you know that they don't change between requests.

Phillip, yes, own cache will be helpful, but this mean, that not only controller needs to be modified, but a set of BE hoooks added to clear relevant caches on new/update/delete/copy/move/localize/etc. operations.

It will increase boilerplate code for each extension, that would like to have caching of entites, while the goal of a framework is to reduce such code and save time of developer.

In addition a database request, that does only return the primary key could be processed as index only scan (when the table has good indexes of course) and the the database would not need to load any of the table data. That could make the building even faster.

Just a few TCA settings are needed to realize that

1st: connect the table to the extbase model/superclass:
TCA[tx_extension_domain_model_test][extbase_model] = 'Vendor\\Extension\\Domain\\Model\\Test';

The general enabling:
config.tx_extbase.persistence.classes.Vendor\Extension\Domain\Model\Test.entityCache = 1

And to modify you could simply register a handler for the specific signal.
There you could add prebuilt imagepaths, links or other processed data.

When persisting an object the standard routine is called and postprocessed by the registered Handler.

When saving a TCA record via the backend the TCA is resolved, if an extbase entity class is connected and the cache is enabled the routine is called based on the TCA values.

I think it would not be so hard to implement, developerts could very easily enable it for their models and if you have good indexes and make good use of it you can have a very dramatic (positive) impact on performance.

I think - with all the work you made so far (regarding performance) - this can be closed.