CQEngine can provide an expiration strategy to prevent the memory space from being used up

[clncon]

I hope that CQEngine can provide some expiration strategies to prevent the collection from growing

[shenzhaoquan]

I also encountered this problem and added a simple implementation CapacityLimitedIndexedCollection @npgall
#289

[npgall]

The best way to handle that is probably to add a timestamp in your objects which indicates the time it was added to the collection. Then define an attribute which reads that timestamp. Then add an index on that attribute. Then, you can write a query which retrieves objects which were added a long time ago, and remove those from the collection.

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On Fri 13 Aug 2021, 13:07 shenzhaoquan, ***@***.***> wrote: I also encountered this problem and added a simple implementation CapacityLimitedIndexedCollection — You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub <#287 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AAVYTCXLEOEKDWC67G2TKL3T4UDJXANCNFSM5BFTFATA> . Triage notifications on the go with GitHub Mobile for iOS <https://apps.apple.com/app/apple-store/id1477376905?ct=notification-email&mt=8&pt=524675> or Android <https://play.google.com/store/apps/details?id=com.github.android&utm_campaign=notification-email> .

[geezerrrr]

The best way to handle that is probably to add a timestamp in your objects which indicates the time it was added to the collection. Then define an attribute which reads that timestamp. Then add an index on that attribute. Then, you can write a query which retrieves objects which were added a long time ago, and remove those from the collection.
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I don't think this is a good way, because we can't know when to clear them. It is possible that OOM occurred before I triggered the cleanup task.

In some cases, users cannot accurately assess how much data is entered into the CQEngine collection. This can easily cause memory overflow problems. A collection with limited capacity can better protect applications using CQEngine.

[npgall]

CQEngine is for running queries on a dataset. If objects are arbitrarily removed from the dataset, then queries will return incorrect results, right? I fail to see how what you propose could be implemented without sacrificing query correctness. OTOH, the application might know which objects can be removed safely without compromising correctness for the particular domain of the application. So it seems sensible to me to have the application manage that itself.

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On Tue 17 Aug 2021, 02:53 s_skinny, ***@***.***> wrote: The best way to handle that is probably to add a timestamp in your objects which indicates the time it was added to the collection. Then define an attribute which reads that timestamp. Then add an index on that attribute. Then, you can write a query which retrieves objects which were added a long time ago, and remove those from the collection. … <#m_-8214920636253633578_> I don't think this is a good way, because we can't know when to clear them. It is possible that OOM occurred before I triggered the cleanup task. In some cases, users cannot accurately assess how much data is entered into the CQEngine collection. This can easily cause memory overflow problems. A collection with limited capacity can better protect applications using CQEngine. — You are receiving this because you were mentioned. Reply to this email directly, view it on GitHub <#287 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AAVYTCQT5L37LXDY5PMQOE3T5G6JRANCNFSM5BFTFATA> . Triage notifications on the go with GitHub Mobile for iOS <https://apps.apple.com/app/apple-store/id1477376905?ct=notification-email&mt=8&pt=524675> or Android <https://play.google.com/store/apps/details?id=com.github.android&utm_campaign=notification-email> .