remove isMerge from build operator

[badboynt1]

User description

What type of PR is this?

• API-change
• BUG
• Improvement
• Documentation
• Feature
• Test and CI
• Code Refactoring

Which issue(s) this PR fixes:

issue #16542

What this PR does / why we need it:

remove isMerge from build operator

---

PR Type

Enhancement

---

Description

• Removed isMerge field and related conditional logic across multiple files.
• Simplified InitReceiver calls to always use true.
• Updated tests to remove redundant channel operations related to MergeReceivers.
• Removed outdated comments about isMergeType.

---

Changes walkthrough 📝

	Relevant files
Enhancement	build.go Simplify receiver initialization and batch collection logic pkg/sql/colexec/hashbuild/build.go Removed conditional logic for isMerge in Prepare and collectBuildBatches functions. Simplified InitReceiver call to always use true. +2/-11    build_test.go Remove redundant MergeReceivers channel operations in tests pkg/sql/colexec/hashbuild/build_test.go Removed redundant channel operations related to MergeReceivers. +0/-4      types.go Remove isMerge field and simplify Free function                    pkg/sql/colexec/hashbuild/types.go Removed isMerge field from container struct. Simplified Free function by removing conditional logic based on isMerge. +0/-6      build.go Simplify receiver initialization and batch collection logic pkg/sql/colexec/indexbuild/build.go Removed conditional logic for isMerge in Prepare and collectBuildBatches functions. Simplified InitReceiver call to always use true. +2/-13    types.go Remove isMerge field and simplify Free function                    pkg/sql/colexec/indexbuild/types.go Removed isMerge field from container struct. Simplified Free function by removing conditional logic based on isMerge. +2/-9      build.go Simplify receiver initialization and batch collection logic pkg/sql/colexec/shufflebuild/build.go Removed conditional logic for isMerge in Prepare and collectBuildBatches functions. Simplified InitReceiver call to always use true. +2/-11    types.go Remove isMerge field and simplify Free function                    pkg/sql/colexec/shufflebuild/types.go Removed isMerge field from container struct. Simplified Free function by removing conditional logic based on isMerge. +0/-6
Documentation	receiver_operator.go Remove outdated comment about isMergeType                                pkg/sql/colexec/receiver_operator.go Removed comment explaining isMergeType. +0/-1

---

💡 PR-Agent usage:
Comment /help on the PR to get a list of all available PR-Agent tools and their descriptions

[codiumai-pr-agent-pro]

PR-Agent was enabled for this repository. To continue using it, please link your git user with your CodiumAI identity here.

PR Review 🔍

⏱️ Estimated effort to review [1-5]	2, because the changes are straightforward and involve removing redundant conditional logic and simplifying method calls across several files. The modifications are consistent and repetitive, making the review process less complex.
🧪 Relevant tests	Yes
⚡ Possible issues	Possible Regression: The removal of conditional logic related to isMerge and the standardization of InitReceiver to always use true might introduce regressions if there were specific reasons or edge cases previously handled by the conditional logic. It's recommended to ensure that all scenarios previously covered by the isMerge logic are still correctly handled.
🔒 Security concerns	No

[codiumai-pr-agent-pro]

PR-Agent was enabled for this repository. To continue using it, please link your git user with your CodiumAI identity here.

PR Code Suggestions ✨

Category	Suggestion	Score
Best practice	Replace panic with error return for better error handling Instead of panicking when arg.RuntimeFilterSpec is nil, consider returning an error. This will make the function more robust and easier to handle in different contexts. pkg/sql/colexec/indexbuild/build.go [33-34] if arg.RuntimeFilterSpec == nil { - panic("there must be runtime filter in index build!") + return errors.New("there must be runtime filter in index build!") } Suggestion importance[1-10]: 8 Why: Replacing a panic with an error return is a significant improvement in error handling. It allows the function to handle errors gracefully and makes the system more robust by not terminating the program unexpectedly.	8

[badboynt1]

https://github.com/matrixorigin/ci-test/actions/runs/9362107618 已经跑过checkin regression了