using emhash for hashagg

[zhouyuan]

This patch replaces the phmap::flat_hash_map with emhash8::HashMap

Signed-off-by: Yuan Zhou yuan.zhou@intel.com

What changes were proposed in this pull request?

(Please fill in changes proposed in this fix)

How was this patch tested?

(Please explain how this patch was tested. E.g. unit tests, integration tests, manual tests)

(If this patch involves UI changes, please attach a screenshot; otherwise, remove this)

[github-actions]

Thanks for opening a pull request!

Could you open an issue for this pull request on Github Issues?

https://github.com/oap-project/native-sql-engine/issues

Then could you also rename commit message and pull request title in the following format?

[NSE-${ISSUES_ID}] ${detailed message}

See also:

• Other pull requests