[jira] [Resolved] (IMPALA-4865) Limit size of literal values from constant folding

["Tim Armstrong (JIRA)" <ji...@apache.org>]

     [ https://issues.apache.org/jira/browse/IMPALA-4865?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Tim Armstrong resolved IMPALA-4865.
-----------------------------------
       Resolution: Fixed
    Fix Version/s: Impala 3.3.0

> Limit size of literal values from constant folding
> --------------------------------------------------
>
>                 Key: IMPALA-4865
>                 URL: https://issues.apache.org/jira/browse/IMPALA-4865
>             Project: IMPALA
>          Issue Type: Bug
>          Components: Frontend
>    Affects Versions: Impala 2.8.0
>            Reporter: Henry Robinson
>            Assignee: Fang-Yu Rao
>            Priority: Major
>              Labels: newbie
>             Fix For: Impala 3.3.0
>
>
> Consider (from {{test_insert.py}}) the following query:
> {{create table foo as select repeat('AZ', 128 * 1024 * 1024) as s}}
> {{repeat()}} gets constant-folded into a 256MB expression payload, which is then transmitted to every fragment instance that evaluates the expression. This can lead to timeouts. 
> The workaround is {{ENABLE_EXPR_REWRITES=0}}.
> It's not obvious what the answer is - should the FE be aware of the serialized size of an expression when deciding whether to constant fold it?



--
This message was sent by Atlassian JIRA
(v7.6.3#76005)