[jira] [Updated] (HIVE-11141) Improve RuleRegExp when the Expression node stack gets huge

["Hari Sankar Sivarama Subramaniyan (JIRA)" <ji...@apache.org>]

     [ https://issues.apache.org/jira/browse/HIVE-11141?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Hari Sankar Sivarama Subramaniyan updated HIVE-11141:
-----------------------------------------------------
    Attachment: HIVE-11141.3.patch

> Improve RuleRegExp when the Expression node stack gets huge
> -----------------------------------------------------------
>
>                 Key: HIVE-11141
>                 URL: https://issues.apache.org/jira/browse/HIVE-11141
>             Project: Hive
>          Issue Type: Bug
>            Reporter: Hari Sankar Sivarama Subramaniyan
>            Assignee: Hari Sankar Sivarama Subramaniyan
>         Attachments: HIVE-11141.1.patch, HIVE-11141.2.patch, HIVE-11141.3.patch, SQLQuery10.sql.mssql, createtable.rtf
>
>
> Hive occasionally gets bottlenecked on generating plans for large queries, the majority of the cases time is spent in fetching metadata, partitions and other optimizer transformation related rules
> I have attached the query for the test case which needs to be tested after we setup database as shown below.
> {code}
> create database dataset_3;
> use database dataset_3;
> {code}
> createtable.rtf - create table command
> SQLQuery10.sql.mssql - explain query
> It seems that the most problematic part of the code as the stack gets arbitrary long, in RuleRegExp.java
> {code}
>   @Override
>   public int cost(Stack<Node> stack) throws SemanticException {
>     int numElems = (stack != null ? stack.size() : 0);
>     String name = "";
>     for (int pos = numElems - 1; pos >= 0; pos--) {
>       name = stack.get(pos).getName() + "%" + name;
>       Matcher m = pattern.matcher(name);
>       if (m.matches()) {
>         return m.group().length();
>       }
>     }
>     return -1;
>   }
> {code}



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