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https://issues.apache.org/jira/browse/DRILL-4609?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16003332#comment-16003332
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Karthikeyan Manivannan commented on DRILL-4609:
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It is unlikely that this is a JVM bug. JDK 7's runtime/JIT-compilation policies
might just be hiding a Drill bug. JVM bugs( like mis-compiles, incorrect class
loading) usually result in a crash.
All that said, given that this is a 1-bit error, it is possible that this is a
JVM bug.
You can eliminate the role of the JIT compiler by trying to repro the bug with
the -Xint( interpreter only, will slow down execution significantly) JVM option.
If you hit the bug with -Xint then you can be fairly certain that this is not a
JVM bug.
> Select true,true,true from ... does not always output true,true,true
> --------------------------------------------------------------------
>
> Key: DRILL-4609
> URL: https://issues.apache.org/jira/browse/DRILL-4609
> Project: Apache Drill
> Issue Type: Bug
> Components: Client - CLI, Query Planning & Optimization, Storage -
> Writer
> Affects Versions: 1.5.0, 1.6.0
> Environment: Linux Redhat
> tested in cluster (hdfs) and embedded mode
> Reporter: F Méthot
>
> Doing a simple "select true, true, true from table" won't output
> true,true,true on all generated rows.
> Step to reproduce.
> generate a simple CSV files:
> {code:sql}
> for i in {1..1000000}; do echo "Allo"; done > /users/fmethot/test.csv
> {code}
> Open a new fresh drill CLI.
> Just to help for validation, switch output to CSV:
> {code:sql}
> alter session set `store.format`='csv'
> {code}
> generate a table like this:
> {code:sql}
> create table TEST_OUT as (select true,true,true,true from
> dfs.`/users/fmethot/test.csv')
> {code}
> Check content of /users/fmethot/test.csv
> You will find false values in there!
> If you generate another table, on the same session, the same way, chances are
> the value will be fine (all true). We can only reproduce this on the first
> CTAS run.
> We came to test this select pattern after we realize our custom boolean UDF
> (as well as the one provided in Drill like "ilike") were not outputting
> consistent deterministic results (same input were implausibly generating
> random boolean output). We hope that fixing this ticket will also fix our
> issue with boolean UDFs.
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