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https://issues.apache.org/jira/browse/FLINK-26401?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17500103#comment-17500103
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zoucao commented on FLINK-26401:
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Hi [~luoyuxia], I know the hive dialect can resolve it, but if we use the
default dialect to read hive catalog view, this problem can not be avoided.
Now, flink use the same Parser to parse the catalog view, if we choose the
default parser to parse the `select * from hive_view` (hive_view consists of
`select a, b from kudu_tb`), the statement `select a, b from kudu_tb` will also
be parsed by default parser.
If the problem is seen as hive syntax compatibility, should we use the default
parser to parse `select * from hive_view`, and hive parser to parse `select a,
b from kudu_tb`?
> improve the compatibility for hive catalogView
> ----------------------------------------------
>
> Key: FLINK-26401
> URL: https://issues.apache.org/jira/browse/FLINK-26401
> Project: Flink
> Issue Type: Improvement
> Components: Connectors / Hive
> Reporter: zoucao
> Priority: Major
>
> For now, many reserved keywords were kept for FlinkSQL[1], and some of them
> are different from other bigdata systems, like spark[2], hive[3]. In this
> context, users may be affected by the compatibility of various systems.
> For example, the keyword 'DATE' is marked as reserved by Flink and Hive, but
> not in spark. If the hive view is defined as
> {code:java}
> select a, b, date from hive_tb where date = '2022-02-28'
> {code}
> It will work well in spark, but in flink, the SqlParserException about ' SQL
> parse failed. Encountered "date" at line xxx, column xxx ' will be thrown.
> IIUC, If we do nothing to improve the compatibility, users must change the
> query about the hive view to
> {code:java}
> select a, b, `date` from hive_tb where `date` = '2022-02-28'
> {code}
> , to make Flink work.
> I think we can add a converter to surround reserved keywords with backticks
> before parsing.
> [1]
> https://nightlies.apache.org/flink/flink-docs-master/docs/dev/table/sql/overview/
> [2]
> https://spark.apache.org/docs/3.2.1/sql-ref-ansi-compliance.html#sql-keywords
> [3]
> https://cwiki.apache.org/confluence/display/Hive/LanguageManual+DDL#LanguageManualDDL-Keywords,Non-reservedKeywordsandReservedKeywords
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