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Posted to github@arrow.apache.org by GitBox <gi...@apache.org> on 2022/06/24 15:07:50 UTC

[GitHub] [arrow-datafusion] mkmik opened a new issue, #2785: EXTRACT(EPOCH from column)

mkmik opened a new issue, #2785:
URL: https://github.com/apache/arrow-datafusion/issues/2785

   **Is your feature request related to a problem or challenge? Please describe what you are trying to do.**
   
   Datafusion supports a few date parts like "year" or "seconds" in the `EXTRACT` operator.
   
   Postgres offers a few more. In particular it offers an `EPOCH` date part which extracts the number of seconds since 1970-01-01 00:00:00-00 (can be negative). 
   
   See https://www.postgresql.org/docs/8.1/functions-datetime.html
   
   My particular use case is using pre-existing grafana postgres plugin, which crafts queries with such a construct. But I think it would be generally useful to support converting a timestamp to a unix epoch.
   
   **Describe the solution you'd like**
   
   ```sql
   select EXTRACT(EPOCH from column) from mytable;
   ```
   
   **Describe alternatives you've considered**
   
   ```sql
   select CAST(column AS bigint)/1000000000 from mytable;
   ```
   
   


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[GitHub] [arrow-datafusion] alamb commented on issue #2785: EXTRACT(EPOCH from column)

Posted by GitBox <gi...@apache.org>.
alamb commented on issue #2785:
URL: https://github.com/apache/arrow-datafusion/issues/2785#issuecomment-1384720257

   Welcome to the community @toprakdeniz ! We have many first time Rust enthusiasts work on DataFusion and look forward to helping get this feature done. 


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[GitHub] [arrow-datafusion] toprakdeniz commented on issue #2785: EXTRACT(EPOCH from column)

Posted by GitBox <gi...@apache.org>.
toprakdeniz commented on issue #2785:
URL: https://github.com/apache/arrow-datafusion/issues/2785#issuecomment-1383235886

   Hello Andrew,
   I need to, and want to help datafusion project.
   I think it is a good start for me.
   I am new to Rust language and this will be the first open source support
   for me.
   I am familiar with software engineering and I have read Andrew Grove's book.
   Best Regards,
   Toprak Deniz
   
   Andrew Lamb ***@***.***>, 12 Oca 2023 Per, 00:01 tarihinde
   şunu yazdı:
   
   > BTW here is a nice contained test case:
   >
   > ❯ select extract(epoch from '1825-08-29T07:29:01.256'::timestamp);
   >
   > ArrowError(ExternalError(Execution("Date part 'EPOCH' not supported")))
   >
   >
   > I think this would be a good first issue
   >
   > —
   > Reply to this email directly, view it on GitHub
   > <https://github.com/apache/arrow-datafusion/issues/2785#issuecomment-1379478377>,
   > or unsubscribe
   > <https://github.com/notifications/unsubscribe-auth/AKZX6ZCZX3DRUBRTDJGPHP3WR4NRLANCNFSM5ZYEUSKA>
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   > ID: ***@***.***>
   >
   


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[GitHub] [arrow-datafusion] mkmik commented on issue #2785: EXTRACT(EPOCH from column)

Posted by GitBox <gi...@apache.org>.
mkmik commented on issue #2785:
URL: https://github.com/apache/arrow-datafusion/issues/2785#issuecomment-1165740748

   I have a draft in https://github.com/apache/arrow-datafusion/pull/2786 ; I tried it out with datafusion-cli
   
   Next, I'll:
   
   1. add tests
   2. try to see if I can simplify it and make it use the same macros that we use for the other date field extractors


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[GitHub] [arrow-datafusion] alamb commented on issue #2785: EXTRACT(EPOCH from column)

Posted by GitBox <gi...@apache.org>.
alamb commented on issue #2785:
URL: https://github.com/apache/arrow-datafusion/issues/2785#issuecomment-1379478377

   BTW here is a nice contained test case: 
   
   ```
   ❯ select extract(epoch from '1825-08-29T07:29:01.256'::timestamp);
   ArrowError(ExternalError(Execution("Date part 'EPOCH' not supported")))
   ```
   
   I think this would be a good first issue


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[GitHub] [arrow-datafusion] alamb commented on issue #2785: EXTRACT(EPOCH from column)

Posted by GitBox <gi...@apache.org>.
alamb commented on issue #2785:
URL: https://github.com/apache/arrow-datafusion/issues/2785#issuecomment-1165720553

   Here is an example of how other parts were added: https://github.com/apache/arrow-datafusion/pull/1974
   
   This may require adding `epoch` kernel to arrow, along the lines of https://github.com/apache/arrow-rs/pull/1891 and then adding appropriate support 


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[GitHub] [arrow-datafusion] alamb closed issue #2785: EXTRACT(EPOCH from column)

Posted by "alamb (via GitHub)" <gi...@apache.org>.
alamb closed issue #2785: EXTRACT(EPOCH from column)
URL: https://github.com/apache/arrow-datafusion/issues/2785


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