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Posted to commits@beam.apache.org by "Jérémie Vexiau (JIRA)" <ji...@apache.org> on 2017/08/25 09:04:00 UTC
[jira] [Updated] (BEAM-2803) JdbcIO read is very slow when query
return a lot of rows
[ https://issues.apache.org/jira/browse/BEAM-2803?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Jérémie Vexiau updated BEAM-2803:
---------------------------------
Attachment: test1M.png
test500k.png
test1500K.png
> JdbcIO read is very slow when query return a lot of rows
> --------------------------------------------------------
>
> Key: BEAM-2803
> URL: https://issues.apache.org/jira/browse/BEAM-2803
> Project: Beam
> Issue Type: Improvement
> Components: sdk-java-extensions
> Affects Versions: Not applicable
> Reporter: Jérémie Vexiau
> Assignee: Reuven Lax
> Labels: performance
> Fix For: Not applicable
>
> Attachments: test1500K.png, test1M.png, test500k.png
>
>
> Hi,
> I'm using JdbcIO reader in batch mode with the postgresql driver.
> my select query return more than 5 Millions rows
> using cursors with Statement.setFetchSize().
> these ParDo are OK :
> {code:java}
> .apply(ParDo.of(new ReadFn<>(this))).setCoder(getCoder())
> .apply(ParDo.of(new DoFn<T, KV<Integer, T>>() {
> private Random random;
> @Setup
> public void setup() {
> random = new Random();
> }
> @ProcessElement
> public void processElement(ProcessContext context) {
> context.output(KV.of(random.nextInt(), context.element()));
> }
> }))
> {code}
> but reshuffle is very very slow.
> it must be the GroupByKey with more than 5 millions of Key.
> {code:java}
> .apply(GroupByKey.<Integer, T>create())
> {code}
> is there a way to optimize the reshuffle, or use another method to prevent fusion ?
> thanks in advance,
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