arangodb/Documentation/DbaManual/IndexCap.md

Cap Constraint

@NAVIGATE_IndexCap @EMBEDTOC{IndexCapTOC}

Introduction to Cap Constraints

This is an introduction to ArangoDB's size restrictions aka cap constraints for collections.

It is possible to restrict the size of collections. If you add a document and the size exceeds the limit, then the least recently created or updated document will be dropped. The size of a collection is measured in the number of (non-deleted) documents a collection contains. Using a cap constraint, a collection can be used as a FIFO container, with just the newest documents remaining in the collection.

For example, this might be to keep a list of just the most recent log entries.

Accessing Cap Constraints from the Shell

@anchor IndexCapShellEnsureCapConstraint @copydetails JS_EnsureCapConstraintVocbaseCol