[opt](split) generate and get split batch concurrently

[AshinGau]

bp #36045, and turn on batch split, which is turn off in #36109

[doris-robot]

Thank you for your contribution to Apache Doris.
Don't know what should be done next? See How to process your PR

Since 2024-03-18, the Document has been moved to doris-website.
See Doris Document.

[github-actions]

clang-tidy review says "All clean, LGTM! 👍"

[github-actions]

clang-tidy review says "All clean, LGTM! 👍"

[morningman]

run buildall

[github-actions]

clang-tidy review says "All clean, LGTM! 👍"

[AshinGau]

run buildall

[github-actions]

clang-tidy review says "All clean, LGTM! 👍"

[github-actions]

clang-tidy review says "All clean, LGTM! 👍"

[doris-robot]

TeamCity be ut coverage result:
Function Coverage: 36.30% (9133/25158)
Line Coverage: 27.79% (74258/267221)
Region Coverage: 26.72% (38319/143387)
Branch Coverage: 23.41% (19409/82914)
Coverage Report: http://coverage.selectdb-in.cc/coverage/01627d7fa8a9068f047d0375d2bfa1078bf2021d_01627d7fa8a9068f047d0375d2bfa1078bf2021d/report/index.html

[github-actions]

clang-tidy review says "All clean, LGTM! 👍"

[AshinGau]

run buildall

[github-actions]

clang-tidy review says "All clean, LGTM! 👍"

[doris-robot]

TeamCity be ut coverage result:
Function Coverage: 36.29% (9131/25158)
Line Coverage: 27.78% (74244/267229)
Region Coverage: 26.72% (38311/143397)
Branch Coverage: 23.40% (19405/82924)
Coverage Report: http://coverage.selectdb-in.cc/coverage/ce6e5eb26c529824c6adf2f332cea188759ab67d_ce6e5eb26c529824c6adf2f332cea188759ab67d/report/index.html

[AshinGau]

run buildall

[github-actions]

clang-tidy review says "All clean, LGTM! 👍"

[doris-robot]

TeamCity be ut coverage result:
Function Coverage: 36.30% (9133/25158)
Line Coverage: 27.79% (74258/267213)
Region Coverage: 26.73% (38318/143374)
Branch Coverage: 23.41% (19405/82892)
Coverage Report: http://coverage.selectdb-in.cc/coverage/a3e478138c343d3f94f1a8b2fd543461bef64cfe_a3e478138c343d3f94f1a8b2fd543461bef64cfe/report/index.html