feat: support ||, position and overlay bytea functions

[guluguluhhhh]

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What's changed and what's your intention?

add support for ||, position and overlay bytea functions in #8831

Checklist

• I have written necessary rustdoc comments.
• I have added necessary unit tests and integration tests.
• I have added test labels as necessary.
• I have added fuzzing tests or opened an issue to track them.
• My PR contains breaking changes.
• My PR changes performance-critical code, so I will run (micro) benchmarks and present the results.
• I have checked the Release Timeline and Currently Supported Versions to determine which release branches I need to cherry-pick this PR into.

Documentation

• My PR needs documentation updates.

Release note

support ||, position and overlay bytea functions

[guluguluhhhh]

@stdrc could you take a look when u r available😁

[Copilot]

Pull Request Overview

Add support for bytea-specific SQL functions: concatenation (||), position, and overlay.

• Expose a new ExprType::ByteaConcatOp in the planner and binder
• Implement bytea_concat_op, bytea_position, overlay_bytea, and overlay_for_bytea in the expression layer
• Update expr.proto to include the new BYTEA_CONCAT_OP node

Reviewed Changes

Copilot reviewed 7 out of 7 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
src/frontend/src/optimizer/plan_expr_visitor/strong.rs	Recognize ExprType::ByteaConcatOp in the planner
src/frontend/src/expr/pure.rs	Treat Type::ByteaConcatOp as a pure expression
src/frontend/src/binder/expr/binary_op.rs	Bind `bytea
src/expr/impl/src/scalar/position.rs	Add bytea_position function and basic tests
src/expr/impl/src/scalar/overlay.rs	Add overlay_bytea, overlay_for_bytea and tests
src/expr/impl/src/scalar/concat_op.rs	Add bytea_concat_op and tests
proto/expr.proto	Define BYTEA_CONCAT_OP in the protobuf enum

Comments suppressed due to low confidence (2)

src/expr/impl/src/scalar/position.rs:79

• Add a unit test for the case where sub_bytea is empty to verify the function returns 1 as documented.

pub fn bytea_position(bytea: &[u8], sub_bytea: &[u8]) -> i32 {

src/expr/impl/src/scalar/overlay.rs:198

• Add a unit test that calls overlay_bytea(..., start = 0) or overlay_for_bytea(..., start = 0, ...) to confirm it returns the expected InvalidParam error.

if start <= 0 {

[stdrc]

Implementation LGTM! Thanks!