[jira] [Resolved] (IMPALA-13166) Queries with many nested views are still slow

["Michael Smith (Jira)" <ji...@apache.org>]

     [ https://issues.apache.org/jira/browse/IMPALA-13166?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Michael Smith resolved IMPALA-13166.
------------------------------------
    Fix Version/s: Impala 5.0.0
       Resolution: Fixed

> Queries with many nested views are still slow
> ---------------------------------------------
>
>                 Key: IMPALA-13166
>                 URL: https://issues.apache.org/jira/browse/IMPALA-13166
>             Project: IMPALA
>          Issue Type: Improvement
>          Components: Frontend
>    Affects Versions: Impala 4.4.0
>            Reporter: Michael Smith
>            Assignee: Michael Smith
>            Priority: Critical
>             Fix For: Impala 5.0.0
>
>
> Further profiling on the query from IMPALA-12800 - and a larger version of the same - show significant time spent in {{Analyzer#registerSlotRef}}. The bulk of the work here is in checking whether a {{SlotDescriptor}} exists in the current {{TupleDescriptor}}, both because {{Path#getFullyQualifiedRawPath}} is expensive and because equals on the resulting list is expensive (especially repeated over every {{SlotDescriptor}} in the {{TupleDescriptor}}.
> There's room for improvement here:
> 1. avoid copying {{rawPath_}} every time we call {{getFullyQualifiedRawPath}}
> 2. use a map to identify whether a {{SlotDescriptor}} already exists at {{Path}} in the current {{TupleDescriptor}}
> 3 other small improvements may exist around memory allocation



--
This message was sent by Atlassian Jira
(v8.20.10#820010)