[teiid-issues] [JBoss JIRA] (TEIID-4520) Support for Exasol Connector

[Rafal Korytkowski (JIRA)]

    [ https://issues.jboss.org/browse/TEIID-4520?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13577498#comment-13577498 ] 

Rafal Korytkowski edited comment on TEIID-4520 at 5/16/18 10:16 AM:
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[~rareddy], do you basically disagree with [~shawkins]? Let's try to get it straight. Here are the options for handling NullOrder.LAST as defaultNullOrder: 

1." _SELECT IntNum FROM BQT1.SmallA ORDER BY IntNum_" will be rewritten to "_SELECT IntNum FROM BQT1.SmallA ORDER BY IntNum NULLS FIRST_" to match Teiid's expected ordering and returning *NULLs as first*.
2. "_SELECT IntNum FROM BQT1.SmallA ORDER BY IntNum_" will not be rewritten and *NULLs will be returned last*.
a) "_SELECT IntNum FROM BQT1.SmallA ORDER BY convert(IntNum, bigdecimal)_" will return *NULLs as first* since Teiid's internal sort will be applied.
b) "_SELECT IntNum FROM BQT1.SmallA ORDER BY convert(IntNum, bigdecimal)_"
 will return *NULLs as last* since Teiid's will respect defaultNullOrder when doing internal sort.

2a is the current behavior, which I don't think is quite right. IMO 1. would be the most expected behavior, however 2b is also acceptable. 


was (Author: rkorytkowski):
[~rareddy], do you basically disagree with [~shawkins]? Let's try to get it straight. Here are the options for handling NullOrder.LAST as defaultNullOrder: 

1. SELECT IntNum FROM BQT1.SmallA ORDER BY IntNum will be rewritten to SELECT IntNum FROM BQT1.SmallA ORDER BY IntNum NULLS FIRST to match Teiid's expected ordering.
2. SELECT IntNum FROM BQT1.SmallA ORDER BY IntNum will not be rewritten and NULLS will be returned last.
a) SELECT IntNum FROM BQT1.SmallA ORDER BY convert(IntNum, bigdecimal) will return NULLS as first since Teiid's internal sort will be applied.
b) SELECT IntNum FROM BQT1.SmallA ORDER BY convert(IntNum, bigdecimal) will return NULLs as last since Teiid's will respect defaultNullOrder when doing internal sort.

2a is the current behavior, which I don't think is quite right. IMO 1. would be the most expected behavior, however 2b is also acceptable. 

> Support for Exasol Connector
> ----------------------------
>
>                 Key: TEIID-4520
>                 URL: https://issues.jboss.org/browse/TEIID-4520
>             Project: Teiid
>          Issue Type: Feature Request
>          Components: Misc. Connectors
>    Affects Versions: 9.x
>            Reporter: Van Halbert
>            Assignee: Rafal Korytkowski
>             Fix For: 10.x, Open To Community
>
>
> Requesting support for Exasol Connector



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