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http://gerrit.cloudera.org:8080/18091 )

Change subject: IMPALA-11057: Speed to hex_int function
......................................................................


Patch Set 5:

(1 comment)

http://gerrit.cloudera.org:8080/#/c/18091/4//COMMIT_MSG
Commit Message:

http://gerrit.cloudera.org:8080/#/c/18091/4//COMMIT_MSG@9
PS4, Line 9: The origin HexInt method is too slow.
> Was there any analysis as to what was slow with stringstream? Perhaps re-us
Yes, the initialization of stringstream is slow because it will hold a global 
lock and get some local info.

As you said. If we reuse stringstream objects, there can be a performance 
improvement of nearly 5 times. But the new algorithm logic can bring 10 times 
performance improvement.

I made the simple test. To run the hex_int function 100 million times.

origin:        42s
reuse:         8.4s
new implement: 4.5s



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Gerrit-Project: Impala-ASF
Gerrit-Branch: master
Gerrit-MessageType: comment
Gerrit-Change-Id: Icf2dc7ea64b60b24f1a9e6ab53725acd40ce88ac
Gerrit-Change-Number: 18091
Gerrit-PatchSet: 5
Gerrit-Owner: Anonymous Coward <[email protected]>
Gerrit-Reviewer: Anonymous Coward <[email protected]>
Gerrit-Reviewer: Impala Public Jenkins <[email protected]>
Gerrit-Reviewer: Kurt Deschler <[email protected]>
Gerrit-Comment-Date: Tue, 14 Dec 2021 15:34:08 +0000
Gerrit-HasComments: Yes

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