[
https://issues.apache.org/jira/browse/KYLIN-5016?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17369199#comment-17369199
]
rongchuan.jin commented on KYLIN-5016:
--------------------------------------
*[Root Cause]*
I found SqlDialect.CALCITE may be null in my debug env, this may be the root
cause of above npe issue which also is empty dialect.
So I try to replace SqlDialect.CALCITE with
SqlDialect.DatabaseProduct.CALCITE.getDialect() which will be initialed for
sure. As SqlDialect.CALCITE is a static field in SqlDialect which might not be
initialize at that time.
> Avoid potential NPE issue in RDBMS Pushdown case
> ------------------------------------------------
>
> Key: KYLIN-5016
> URL: https://issues.apache.org/jira/browse/KYLIN-5016
> Project: Kylin
> Issue Type: Improvement
> Components: RDBMS Source
> Affects Versions: v2.6.5, v3.1.2
> Reporter: rongchuan.jin
> Assignee: rongchuan.jin
> Priority: Minor
>
> When I use pushdown with RDBMS source, I encounter some error when convert
> sql which leads to pushdown failing.
> I find below stacktrace like
> {code:java}
> 2020-12-23 13:14:10,212 ERROR [Query a1bf28bb-de28-433e-ab96-28ce234a1a4a-76]
> conv.SqlConverter : Failed to default convert sql, will use the origin input:
> select 1 from `MOVIES_10M`.`DIM_MOVIES_10M` 2LIMIT 500
> 3java.lang.NullPointerException 4 at
> org.apache.calcite.sql.SqlCall.unparse(SqlCall.java:103) 5 at
> org.apache.calcite.sql.pretty.SqlPrettyWriter.format(SqlPrettyWriter.java:806)
> 6 at
> org.apache.kylin.sdk.datasource.framework.conv.SqlConverter.convertSql(SqlConverter.java:69)
> 7 at
> org.apache.kylin.sdk.datasource.framework.JdbcConnector.convertSql(JdbcConnector.java:91)
> 8 at
> org.apache.kylin.sdk.datasource.PushDownRunnerSDKImpl.executeQuery(PushDownRunnerSDKImpl.java:55)
> 9 at
> org.apache.kylin.query.util.PushDownUtil.tryPushDownQuery(PushDownUtil.java:173)
> 10 at
> org.apache.kylin.query.util.PushDownUtil.tryPushDownSelectQuery(PushDownUtil.java:103)
> 11 at
> org.apache.kylin.rest.service.QueryService.tryPushDownSelectQuery(QueryService.java:773)
> 12 at
> org.apache.kylin.rest.service.QueryService.pushDownQuery(QueryService.java:709)
> 13 at
> org.apache.kylin.rest.service.QueryService.queryWithSqlMassage(QueryService.java:700)
> 14 at
> org.apache.kylin.rest.service.QueryService.query(QueryService.java:231) 15 at
> org.apache.kylin.rest.service.QueryService.queryAndUpdateCache(QueryService.java:577)
> 16 at
> org.apache.kylin.rest.service.QueryService.queryWithCache(QueryService.java:512)
> 17 at
> org.apache.kylin.rest.service.QueryService.doQueryWithCache(QueryService.java:395){code}
>
--
This message was sent by Atlassian Jira
(v8.3.4#803005)
