db-derby-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Harshvardhan Gupta (JIRA)" <j...@apache.org>
Subject [jira] [Updated] (DERBY-6938) Obtain cardinality estimates and true estimates for base tables as well as for intermediate results for queries involving multiple joins.
Date Sat, 22 Jul 2017 11:46:01 GMT

     [ https://issues.apache.org/jira/browse/DERBY-6938?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]

Harshvardhan Gupta updated DERBY-6938:
--------------------------------------
    Attachment: traceout.txt

Following my previous comment I am also attaching the sample optimizer trace of Query 1a of
job dataset where Optimizer ignores the HASH Tables which it predicts will spill to disk.

trace output String - "Skipping access path due to excess memory usage, maximum is 1048576".

>  Obtain cardinality estimates and true estimates for base tables as well as for intermediate
results for queries involving multiple joins. 
> -------------------------------------------------------------------------------------------------------------------------------------------
>
>                 Key: DERBY-6938
>                 URL: https://issues.apache.org/jira/browse/DERBY-6938
>             Project: Derby
>          Issue Type: Sub-task
>          Components: SQL
>            Reporter: Harshvardhan Gupta
>            Assignee: Harshvardhan Gupta
>         Attachments: explain.txt, traceout.txt
>
>




--
This message was sent by Atlassian JIRA
(v6.4.14#64029)

Mime
View raw message