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GlueSQL

  • Type: Open-source contribution
  • Period: Jun 2021 - Present

Implementing DISTINCT Execution Semantics

Problem and diagnosis: SELECT DISTINCT syntax information did not reach GlueSQL's Rust SQL engine executor, so the query produced the same result as a regular SELECT. Projection and aggregate execution identify duplicates at different state boundaries.

Constraints and decision: I had to leave non-DISTINCT results unchanged and remove duplicates only at the two state boundaries where final values are produced. Unsupported DISTINCT ON returns an explicit error.

Scroll horizontally to inspect the full flow.

DISTINCT syntax moves through the parser and AST into the query model, then the execution path deduplicates projected rows or aggregate inputs before regression tests verify the behavior.

Implementation: I propagated parser/AST output into the query model, then connected row deduplication and aggregate handling in the SQL executor with AST Builder APIs. I also strengthened value equality, hashing, and map-key ordering so duplicate detection remained deterministic.

Validation and result: Regression tests covered single and multiple columns, maps, schemaless rows, and aggregate DISTINCT, including COUNT. The feature and tests preserve the same meaning across SQL input, internal representation, and execution output.

Implementing the AST Query Interface, Parquet Storage, and CLI

AST Query Interface

I implemented AST Builder aggregate helpers and COUNT argument handling, then updated executor and test paths so aggregate functions could evaluate expression arguments rather than only simple columns.

Parquet Storage and CLI

I connected Parquet storage to GlueSQL's storage traits and SQL execution, adding file read/write, schema and value conversion, documentation, tests, and a CLI usage path. I later updated the related code to meet clippy::pedantic checks.

Review, Mentoring, and Awards

I authored 50 merged pull requests in gluesql/gluesql. I now participate in code review and maintenance as a GlueSQL reviewer, reviewing contributor pull requests for error handling, edge cases, test coverage, and code organization. As an OSSCA mentor in 2023, I guided contributors through Rust project workflows, GlueSQL internals, storage, AST Builder, and function implementation.

Year Program Award
2023 Open Source Contribution Academy GlueSQL team award while I participated as a mentor: NIPA President Award (Encouragement)
2022 Open Source Contribution Academy NIPA President Award (Top Excellence)
2021 Open Source Contribution Academy NIPA President Award (Top Excellence)