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https://issues.apache.org/jira/browse/CASSANDRA-8231?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14194840#comment-14194840
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Jonathan Ellis commented on CASSANDRA-8231:
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JAMM provides something similar with ObjectSizes.

> Wrong size of cached prepared statements
> ----------------------------------------
>
>                 Key: CASSANDRA-8231
>                 URL: https://issues.apache.org/jira/browse/CASSANDRA-8231
>             Project: Cassandra
>          Issue Type: Bug
>          Components: Core
>            Reporter: Jaroslav Kamenik
>            Assignee: Benjamin Lerer
>         Attachments: 8231-notes.txt, Unsafes.java
>
>
> Cassandra counts memory footprint of prepared statements for caching 
> purposes. It seems, that there is problem with some statements, ie 
> SelectStatement. Even simple selects is counted as 100KB object, updates, 
> deletes etc have few hundreds or thousands bytes. Result is that cache - 
> QueryProcessor.preparedStatements  - holds just fraction of statements..
> I dig a little into the code, and it seems that problem is in jamm in class 
> MemoryMeter. It seems that if instance contains reference to class, it counts 
> size of whole class too. SelectStatement references EnumSet through 
> ResultSet.Metadata and EnumSet holds reference to Enum class...



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