[ 
https://issues.apache.org/jira/browse/BEAM-12044?focusedWorklogId=572739&page=com.atlassian.jira.plugin.system.issuetabpanels:worklog-tabpanel#worklog-572739
 ]

ASF GitHub Bot logged work on BEAM-12044:
-----------------------------------------

                Author: ASF GitHub Bot
            Created on: 26/Mar/21 16:41
            Start Date: 26/Mar/21 16:41
    Worklog Time Spent: 10m 
      Work Description: turb commented on a change in pull request #14338:
URL: https://github.com/apache/beam/pull/14338#discussion_r602440411



##########
File path: 
sdks/java/io/jdbc/src/main/java/org/apache/beam/sdk/io/jdbc/JdbcIO.java
##########
@@ -903,6 +903,8 @@ public void processElement(ProcessContext context) throws 
Exception {
       if (connection == null) {
         connection = dataSource.getConnection();
       }
+      // PostgreSQL requires autocommit to be disabled to enable cursor 
streaming

Review comment:
       If I have an idea on how the parameter can be specified, it will be 
additional work yes, but I can spend some reasonable time on it.
   
   However, I am inclined to invoke YAGNI principle: once this parameter is 
needed (and I can't determine how someone would need autocommit while reading), 
the way to parameterize it and to take it into account in `JdbcIO` will appear 
more clearly.




-- 
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.

For queries about this service, please contact Infrastructure at:
us...@infra.apache.org


Issue Time Tracking
-------------------

    Worklog Id:     (was: 572739)
    Time Spent: 2h 10m  (was: 2h)

> JdbcIO should explicitly setAutoCommit to false
> -----------------------------------------------
>
>                 Key: BEAM-12044
>                 URL: https://issues.apache.org/jira/browse/BEAM-12044
>             Project: Beam
>          Issue Type: Bug
>          Components: sdk-java-core
>    Affects Versions: 2.28.0
>            Reporter: Sylvain Veyrié
>            Priority: P2
>          Time Spent: 2h 10m
>  Remaining Estimate: 0h
>
> Hello,
> Per [PostgreSQL JDBC 
> documentation|https://jdbc.postgresql.org/documentation/head/query.html#query-with-cursor],
>  autocommit must be explicitly disabled on the connection to allow cursor 
> streaming.
> [~jkff] mentionned it [on the mailing 
> list|https://www.mail-archive.com/dev@beam.apache.org/msg16808.html], however 
> even if there is:
> {code:java}
> poolableConnectionFactory.setDefaultAutoCommit(false);
> {code}
> in JdbcIO:1555, currently, at least with JDBC driver 42.2.16, any read with 
> JdbcIO will memoize the whole dataset (which leads to OOM), since 
> {code:java}
> connection.getAutoCommit()
> {code}
> returns true in JdbcIO#ReadFn#processElement.
> I can provide a PR — the patch is pretty simple (and solves the problem for 
> us in 2.28.0):
> {code:java}
> if (connection == null) {
>         connection = dataSource.getConnection();
> }
> connection.setAutoCommit(false); // line added
> {code}
> Thanks!



--
This message was sent by Atlassian Jira
(v8.3.4#803005)

Reply via email to