Description
There are a lot of UDFs which would show major performance differences if one assumes that some of its arguments are constant.
Consider, for example, any UDF that takes a regular expression as input: This can be complied once (fast) if it's a constant, or once per row (wicked slow) if it's not a constant.
Or, consider any UDF that reads from a file and/or takes a filename as input; it would have to re-read the whole file if the filename changes.
Attachments
Attachments
Issue Links
- duplicates
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HIVE-1360 Allow UDFs to access constant parameter values at compile time
- Closed
- links to