Github user steveloughran commented on the issue:
https://github.com/apache/spark/pull/14038
There's no performance problem from filtering just on names. It's when
people try to filter on more complex things (file type, timestamp) they need to
call `getFileStatus(path)` and that's the performance problem.
I've been through Spark looking at where anything like that is being done,
and have a patch to fix it....i don't want to have to do the same thing again
in future; something we can avoid by having a richer filter which passes the
`FileStatus` generated in the listing process.
Now, you may think "why doesn't Hadoop's list/glob operations take a richer
predicate?". That I can't answer, it's history is lost in the oldest bits of
the code.
---
If your project is set up for it, you can reply to this email and have your
reply appear on GitHub as well. If your project does not have this feature
enabled and wishes so, or if the feature is enabled but not working, please
contact infrastructure at [email protected] or file a JIRA ticket
with INFRA.
---
---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]
