percona/percona-server-mongodb
Jun 2025 – Jul 2025
2 Months active
Languages Used
C++JavaScriptPythonShell
Technical Skills
Aggregation FrameworkBackend DevelopmentCode RefactoringDatabaseDatabase InternalsDatabase Management
Asher Kornfeld
PROFILE
Asher Kornfeld
Asher Kornfeld contributed to percona/percona-server-mongodb by developing diagnostic and performance calibration tooling focused on query planning and cost modeling. He enhanced error messaging for query features, such as USER_ROLES and $lookup, improving troubleshooting clarity after an IDL refactor. Asher implemented Exact Cardinality Estimation in the query planner using C++ and Python, integrating new interfaces and validation tests. He also introduced a workload-driven calibration workflow for LIMIT operations, adding predictive modeling and regression visualization. His work demonstrated depth in backend development, database internals, and performance tuning, resulting in more accurate cost estimation and stable performance for complex query workloads.
Overall Statistics
Feature vs Bugs
75%Features
Repository Contributions
7Total
Bugs
1
Commits
7
Features
3
Lines of code
2,789
Activity Months2
Your Network
522 people
Work History
July 2025
2 Commits • 2 Features
Jul 1, 2025Month: 2025-07 — Performance-focused feature work delivered in percona/percona-server-mongodb, with significant enhancements to query planning and LIMIT workload modeling. Key contributions include the introduction of Exact Cardinality Estimation (ExactCE) for the query planner and a new LIMIT cost model calibration workflow, each backed by tests and instrumentation.
2 Commits • 2 Features
Jul 1, 2025Month: 2025-07 — Performance-focused feature work delivered in percona/percona-server-mongodb, with significant enhancements to query planning and LIMIT workload modeling. Key contributions include the introduction of Exact Cardinality Estimation (ExactCE) for the query planner and a new LIMIT cost model calibration workflow, each backed by tests and instrumentation.
July 2025
June 2025
5 Commits • 1 Features
Jun 1, 2025June 2025 monthly summary for percona/percona-server-mongodb focused on diagnostic quality and calibration tooling. Delivered improved operational diagnostics and laid groundwork for scalable performance modeling. Key outcomes include enhanced error messaging for query features (USER_ROLES and $lookup) and significant progress on cost model calibration by enabling parsing of classic execution trees and migrating representations from ABT to QSN, reducing ambiguity and enabling more accurate cost estimates.
June 2025
5 Commits • 1 Features
Jun 1, 2025June 2025 monthly summary for percona/percona-server-mongodb focused on diagnostic quality and calibration tooling. Delivered improved operational diagnostics and laid groundwork for scalable performance modeling. Key outcomes include enhanced error messaging for query features (USER_ROLES and $lookup) and significant progress on cost model calibration by enabling parsing of classic execution trees and migrating representations from ABT to QSN, reducing ambiguity and enabling more accurate cost estimates.
Activity
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Quality Metrics
Correctness94.2%
Maintainability92.8%
Architecture92.8%
Performance78.6%
AI Usage20.0%
Skills & Technologies
Programming Languages
C++JavaScriptPythonShell
Technical Skills
Aggregation FrameworkBackend DevelopmentC++ DevelopmentCode RefactoringCost ModelingData AnalysisDatabaseDatabase InternalsDatabase ManagementError HandlingJavaScript TestingPerformance CalibrationPerformance TuningPython DevelopmentQuery Optimization
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