[
https://issues.apache.org/jira/browse/HIVE-416?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12700261#action_12700261
]
Ashish Thusoo commented on HIVE-416:
------------------------------------
A couple of minor comments:
1. Do we still need k=5 in the alterStatement rule considering that the ties
can be broken by k=3 lookahead in alterStatementSuffix.
2. In the select list and select clause can factor out KW_SELECT as that is the
common part in the two options in the selectClause rule.
> Get rid of backtrack in Hive.g
> ------------------------------
>
> Key: HIVE-416
> URL: https://issues.apache.org/jira/browse/HIVE-416
> Project: Hadoop Hive
> Issue Type: Improvement
> Components: Query Processor
> Affects Versions: 0.4.0
> Reporter: Zheng Shao
> Assignee: Zheng Shao
> Fix For: 0.4.0
>
> Attachments: HIVE-416.1.1.patch, HIVE-416.1.patch
>
>
> Hive.g now still uses "backtrack=true". "backtrack" not only slows down the
> parsing in case of error, it can also produce wrong syntax error messages
> (usually based on the last try of the backtracking).
> We should follow
> http://www.antlr.org/wiki/display/ANTLR3/How+to+remove+global+backtracking+from+your+grammar
> to remove the need of doing backtrack.
--
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.
