You are viewing a plain text version of this content. The canonical link for it is here.
Posted to github@arrow.apache.org by GitBox <gi...@apache.org> on 2021/04/26 13:18:07 UTC
[GitHub] [arrow-datafusion] alamb opened a new issue #89: [rust][datafusion] optimize count(*) queries on parquet sources
alamb opened a new issue #89:
URL: https://github.com/apache/arrow-datafusion/issues/89
*Note*: migrated from original JIRA: https://issues.apache.org/jira/browse/ARROW-8902
Currently, as far as I can tell, when you perform a `select count(*) from dataset` in datafusion against a parquet dataset, the way this is implemented is by doing a scan on column 0, and counting up all of the rows (specifically I think it counts the # of rows in each batch).
However, for the specific case of just counting _everythign_ in a parquet file, you can just read the rowcount from the footer metadata, so it's O(1) instead of O(n)
--
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.
For queries about this service, please contact Infrastructure at:
users@infra.apache.org
[GitHub] [arrow-datafusion] Dandandan commented on issue #89: [rust][datafusion] optimize count(*) queries on parquet sources
Posted by GitBox <gi...@apache.org>.
Dandandan commented on issue #89:
URL: https://github.com/apache/arrow-datafusion/issues/89#issuecomment-901094707
This is implemented
--
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.
To unsubscribe, e-mail: github-unsubscribe@arrow.apache.org
For queries about this service, please contact Infrastructure at:
users@infra.apache.org
[GitHub] [arrow-datafusion] alamb closed issue #89: [rust][datafusion] optimize count(*) queries on parquet sources
Posted by GitBox <gi...@apache.org>.
alamb closed issue #89:
URL: https://github.com/apache/arrow-datafusion/issues/89
--
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.
To unsubscribe, e-mail: github-unsubscribe@arrow.apache.org
For queries about this service, please contact Infrastructure at:
users@infra.apache.org
[GitHub] [arrow-datafusion] alamb commented on issue #89: [rust][datafusion] optimize count(*) queries on parquet sources
Posted by GitBox <gi...@apache.org>.
alamb commented on issue #89:
URL: https://github.com/apache/arrow-datafusion/issues/89#issuecomment-826828222
Comment from Andrew Lamb(alamb) @ 2021-04-26T12:31:08.482+0000:
<pre>Migrated to github: https://github.com/apache/arrow-rs/issues/75</pre>
--
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.
For queries about this service, please contact Infrastructure at:
users@infra.apache.org
[GitHub] [arrow-datafusion] alamb commented on issue #89: [rust][datafusion] optimize count(*) queries on parquet sources
Posted by GitBox <gi...@apache.org>.
alamb commented on issue #89:
URL: https://github.com/apache/arrow-datafusion/issues/89#issuecomment-901103163
Closed in https://github.com/apache/arrow-datafusion/pull/620
--
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.
To unsubscribe, e-mail: github-unsubscribe@arrow.apache.org
For queries about this service, please contact Infrastructure at:
users@infra.apache.org
[GitHub] [arrow-datafusion] alamb closed issue #89: [rust][datafusion] optimize count(*) queries on parquet sources
Posted by GitBox <gi...@apache.org>.
alamb closed issue #89:
URL: https://github.com/apache/arrow-datafusion/issues/89
--
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.
To unsubscribe, e-mail: github-unsubscribe@arrow.apache.org
For queries about this service, please contact Infrastructure at:
users@infra.apache.org
[GitHub] [arrow-datafusion] Dandandan commented on issue #89: [rust][datafusion] optimize count(*) queries on parquet sources
Posted by GitBox <gi...@apache.org>.
Dandandan commented on issue #89:
URL: https://github.com/apache/arrow-datafusion/issues/89#issuecomment-901094707
This is implemented
--
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.
To unsubscribe, e-mail: github-unsubscribe@arrow.apache.org
For queries about this service, please contact Infrastructure at:
users@infra.apache.org
[GitHub] [arrow-datafusion] alamb commented on issue #89: [rust][datafusion] optimize count(*) queries on parquet sources
Posted by GitBox <gi...@apache.org>.
alamb commented on issue #89:
URL: https://github.com/apache/arrow-datafusion/issues/89#issuecomment-901103163
Closed in https://github.com/apache/arrow-datafusion/pull/620
--
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.
To unsubscribe, e-mail: github-unsubscribe@arrow.apache.org
For queries about this service, please contact Infrastructure at:
users@infra.apache.org