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https://issues.apache.org/jira/browse/CASSANDRA-3091?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13092862#comment-13092862
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Rick Shaw edited comment on CASSANDRA-3091 at 8/29/11 2:38 PM:
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It is cached in the statement as well so it will do the fetch one time when the
statement is first created and then just check the cache to make sure the
metadata is there and attempt a reload only if it does not find it. Once you
acquire a statement you usually hold on to it for the duration of your task. So
not significantly more than if you acquired a connection.
Note in JDBC it is the {{Statement}} that is used to execute commands, not
{{Connection}}.
was (Author: ardot):
It is cached in the statement as well so it will do the fetch one time when
the statement is first created and then just check the cache to make sure the
metadata is there and attempt a reload only if it does not find it. Once you
acquire a statement you usually hold on to it for the duration of your task. So
not significantly more than if you acquired a connection.
> Move the caching of KS and CF metadata in the JDBC suite from Connection to
> Statement
> -------------------------------------------------------------------------------------
>
> Key: CASSANDRA-3091
> URL: https://issues.apache.org/jira/browse/CASSANDRA-3091
> Project: Cassandra
> Issue Type: Improvement
> Components: Drivers
> Affects Versions: 0.8.4
> Reporter: Rick Shaw
> Assignee: Rick Shaw
> Priority: Minor
> Labels: JDBC
> Fix For: 0.8.5
>
> Attachments: move-metadata-for decoder-to-statement-level-v1.txt,
> move-metadata-for-decoder-to-statement-level-v2.txt
>
>
> Currently, all caching of metadata used in JDBC's {{ColumnDecoder}} class is
> loaded and held in the {{CassandraConnection}} class. The implication of this
> is that any activity on the connected server from the time the connection is
> established is not reflected in the KSs and CF that can be accessed by the
> {{ResultSet, Statement}} and {{PreparedStatement}}.
> By moving the cached metadata to the {{Statement}} level, the currency of the
> metadata can be checked within the {{Statement}} and reloaded if it is seen
> to be absent. And by instantiating a new {{Statement}} (on any existing
> connection) you are assured of getting the most current copy of the metadata
> known to the server at the new time of instantiation.
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