[jira] [Commented] (IGNITE-5397) JDBC thin driver: clear server cursor automatically when last result piece is transmitted

["Vladimir Ozerov (JIRA)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/IGNITE-5397?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16037539#comment-16037539 ] 

Vladimir Ozerov commented on IGNITE-5397:
-----------------------------------------

[~skalashnikov], as I understand with proposed approach we will have an issue with result set metadata. I propose the following approach:
1) For pure DML statements there is not metadata and no result set, so we can apply this optimization in a clean and consistent fashion.
2) As far as SQL requests, let's add special flag to connection properties, which will manage this behavior. When set to "false" (default), server side cursor will not be closed, hence we favor correctness over performance. WHen set to "true" it will close server-side cursor, and any call to result set metadata will produce {{SQLException}} in cursor is already closed. Let's name this flag {{autoCloseServerCursors}}.

> JDBC thin driver: clear server cursor automatically when last result piece is transmitted
> -----------------------------------------------------------------------------------------
>
>                 Key: IGNITE-5397
>                 URL: https://issues.apache.org/jira/browse/IGNITE-5397
>             Project: Ignite
>          Issue Type: Task
>          Components: sql
>    Affects Versions: 2.0
>            Reporter: Vladimir Ozerov
>            Assignee: Sergey Kalashnikov
>              Labels: performance
>             Fix For: 2.1
>
>
> When last part of result set is sent from the server, we should do the following:
> 1) Clear server-side cursor
> 2) Set special marker on the client side that "cursor" close request is not needed. This way we will save two network hops for typical DML request.



--
This message was sent by Atlassian JIRA
(v6.3.15#6346)