[JBoss JIRA] (TEIID-4520) Support for Exasol Connector
by Rafal Korytkowski (JIRA)
[ https://issues.jboss.org/browse/TEIID-4520?page=com.atlassian.jira.plugin... ]
Rafal Korytkowski edited comment on TEIID-4520 at 5/16/18 10:16 AM:
--------------------------------------------------------------------
[~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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[JBoss JIRA] (TEIID-4520) Support for Exasol Connector
by Rafal Korytkowski (JIRA)
[ https://issues.jboss.org/browse/TEIID-4520?page=com.atlassian.jira.plugin... ]
Rafal Korytkowski commented on TEIID-4520:
------------------------------------------
[~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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[JBoss JIRA] (TEIID-4520) Support for Exasol Connector
by Rafal Korytkowski (JIRA)
[ https://issues.jboss.org/browse/TEIID-4520?page=com.atlassian.jira.plugin... ]
Rafal Korytkowski commented on TEIID-4520:
------------------------------------------
BTW down to 113 issues. More than half of them is caused by the above mismatch of internal and source ordering, which can be quickly resolved once I get an answer to my question. Looking into the rest.
> 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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[JBoss JIRA] (TEIID-4520) Support for Exasol Connector
by Rafal Korytkowski (JIRA)
[ https://issues.jboss.org/browse/TEIID-4520?page=com.atlassian.jira.plugin... ]
Rafal Korytkowski commented on TEIID-4520:
------------------------------------------
Okay, understood! In such a case shouldn't TEIID engine use the defaultNullOrder for the given source as well when ordering internally e.g. after applying convert on an ORDER BY column?
> 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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[JBoss JIRA] (TEIID-4520) Support for Exasol Connector
by Steven Hawkins (JIRA)
[ https://issues.jboss.org/browse/TEIID-4520?page=com.atlassian.jira.plugin... ]
Steven Hawkins commented on TEIID-4520:
---------------------------------------
> Just to clarify shall I go ahead and try to modify ORDER BY so that NULLS FIRST is explicitly appended when one sets NullOrder.LAST as defaultNullOrder of the source in translator?
If you are using the default sql conversion visitor it will all any null ordering explicitly set by the user / engine. If none is specified, it is expected that the translator will return results that match the defaultNullOrder - so generally you don't have to do anything special in that case.
> 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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[JBoss JIRA] (TEIID-4520) Support for Exasol Connector
by Rafal Korytkowski (JIRA)
[ https://issues.jboss.org/browse/TEIID-4520?page=com.atlassian.jira.plugin... ]
Rafal Korytkowski commented on TEIID-4520:
------------------------------------------
It worked thanks! Just to clarify shall I go ahead and try to modify ORDER BY so that NULLS FIRST is explicitly appended when one sets NullOrder.LAST as defaultNullOrder of the source in translator?
> 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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7 years, 10 months