we create a collection with limited size 100000: > db.createCollection(“colcase1”, {capped:true, size:100000}) { “ok” : 1 } > show collections colcase colcase1 system.indexes > and, we can convert a exist collection to a limited one: > db.colcase.isCapped() false > db.runCommand({“convertToCapped”:”colcase”,size:100000}) { “ok” : 1 } > db.colcase.isCapped() true > Look ! we did it

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