apache/impala
Sep 2024 – Feb 2026
10 Months active
Languages Used
C++PythonJavaSQLThriftFlatBuffersXML
Technical Skills
C++Pythonback end developmenttestingBackend DevelopmentData Management
Noemi Pap-Takacs
PROFILE
Noemi Pap-takacs
Over ten months, contributed to apache/impala by building and refining backend features focused on Iceberg table integration, catalog management, and query reliability. Leveraging Java, C++, and SQL, delivered enhancements such as memory-optimized update paths for Iceberg on HDFS, robust partition reporting for time travel queries, and a repair utility to address dangling metadata references. Improved test reliability by isolating metadata invalidation and resolving concurrency issues in parallel test execution. Authored documentation to support developer onboarding and incident response. The work emphasized maintainability, performance tuning, and data integrity, resulting in more stable deployments and efficient workflows for distributed data environments.
Overall Statistics
Feature vs Bugs
57%Features
Repository Contributions
15Total
Bugs
6
Commits
15
Features
8
Lines of code
3,543
Activity Months10
Your Network
149 peopleSame Organization
@cloudera.com98
Shared Repositories
51
Work History
February 2026
1 Commits
Feb 1, 2026February 2026 monthly summary for apache/impala focusing on reliability of the test suite and stability improvements. Delivered a targeted fix to isolate metadata invalidation to per-table scope, reducing cross-test interference and flaky failures. This directly improved CI feedback loops and confidence in test results.
1 Commits
Feb 1, 2026February 2026 monthly summary for apache/impala focusing on reliability of the test suite and stability improvements. Delivered a targeted fix to isolate metadata invalidation to per-table scope, reducing cross-test interference and flaky failures. This directly improved CI feedback loops and confidence in test results.
February 2026
November 2025
1 Commits • 1 Features
Nov 1, 2025Monthly work summary for 2025-11 focused on improving developer experience and reliability around Iceberg table repair in Apache Impala. Key delivery: Iceberg Table Repair Documentation, detailing how to repair metadata and considerations when deleting files, enabling safe recovery workflows for Iceberg-backed tables. Summary reflects code review participation, local validation, and alignment with product goals for maintainability and risk mitigation.
November 2025
1 Commits • 1 Features
Nov 1, 2025Monthly work summary for 2025-11 focused on improving developer experience and reliability around Iceberg table repair in Apache Impala. Key delivery: Iceberg Table Repair Documentation, detailing how to repair metadata and considerations when deleting files, enabling safe recovery workflows for Iceberg-backed tables. Summary reflects code review participation, local validation, and alignment with product goals for maintainability and risk mitigation.
October 2025
1 Commits • 1 Features
Oct 1, 20252025-10 monthly summary for apache/impala: Delivered a robust Iceberg metadata repair capability to address dangling references caused by direct storage deletions. Implemented a repair utility and a repair statement to purge missing-file references from Iceberg metadata, improving table integrity and query reliability. Noted limitation: missing delete files cannot be removed via Iceberg DeleteFiles API. Extensive end-to-end validation across HDFS, S3, and Ozone confirmed safety and effectiveness. Commit reference included: fdad9d32041a736108b876704bd0354090a88d29 (IMPALA-13725).
1 Commits • 1 Features
Oct 1, 20252025-10 monthly summary for apache/impala: Delivered a robust Iceberg metadata repair capability to address dangling references caused by direct storage deletions. Implemented a repair utility and a repair statement to purge missing-file references from Iceberg metadata, improving table integrity and query reliability. Noted limitation: missing delete files cannot be removed via Iceberg DeleteFiles API. Extensive end-to-end validation across HDFS, S3, and Ozone confirmed safety and effectiveness. Commit reference included: fdad9d32041a736108b876704bd0354090a88d29 (IMPALA-13725).
October 2025
June 2025
1 Commits • 1 Features
Jun 1, 2025June 2025 monthly summary for apache/impala focusing on business value and technical achievements. Key features delivered include improved Iceberg partition reporting accuracy and time travel handling. Major bugs fixed: none reported this month. Overall impact: enhanced reliability and observability for Iceberg-based workloads, enabling precise time travel queries and more accurate partition counting, which supports cost control and user trust. Technologies/skills demonstrated: Apache Iceberg integration, partition value extraction from file descriptors, efficient storage of partition metadata, and change management linked to IMPALA-13267.
June 2025
1 Commits • 1 Features
Jun 1, 2025June 2025 monthly summary for apache/impala focusing on business value and technical achievements. Key features delivered include improved Iceberg partition reporting accuracy and time travel handling. Major bugs fixed: none reported this month. Overall impact: enhanced reliability and observability for Iceberg-based workloads, enabling precise time travel queries and more accurate partition counting, which supports cost control and user trust. Technologies/skills demonstrated: Apache Iceberg integration, partition value extraction from file descriptors, efficient storage of partition metadata, and change management linked to IMPALA-13267.
April 2025
3 Commits • 2 Features
Apr 1, 2025April 2025 highlights for Apache Impala focusing on catalog maintainability and Iceberg integration. Delivered three focused contributions that improve code quality, test reliability, and DDL correctness, setting the stage for faster future changes and more robust deployments. Key outcomes include (1) a catalog and frontend refactor to prepare for future changes; (2) robust Iceberg metadata tests adaptable to environments with or without erasure coding; (3) corrections to Iceberg DDL transient_lastDdlTime handling and expanded DDL tests for managed/non-managed Iceberg tables. These efforts reduce maintenance cost, improve deployment reliability across environments, and enable smoother rollout of upcoming catalog and Iceberg enhancements.
3 Commits • 2 Features
Apr 1, 2025April 2025 highlights for Apache Impala focusing on catalog maintainability and Iceberg integration. Delivered three focused contributions that improve code quality, test reliability, and DDL correctness, setting the stage for faster future changes and more robust deployments. Key outcomes include (1) a catalog and frontend refactor to prepare for future changes; (2) robust Iceberg metadata tests adaptable to environments with or without erasure coding; (3) corrections to Iceberg DDL transient_lastDdlTime handling and expanded DDL tests for managed/non-managed Iceberg tables. These efforts reduce maintenance cost, improve deployment reliability across environments, and enable smoother rollout of upcoming catalog and Iceberg enhancements.
April 2025
March 2025
1 Commits • 1 Features
Mar 1, 20252025-03 Monthly Summary for apache/impala: Focused on feature delivery around Iceberg integration in local catalog mode. Key outcomes include a refactor that decouples IcebergTable.getPartialInfo() from internal hdfsTable_, and moves the creation of TPartialPartitionInfo from tables to partitions, aligning with unpartitioned HDFS table behavior. This enhances consistency, maintainability, and user-facing behavior in local catalog scenarios. No major bug fixes were recorded this month; the emphasis was on delivering a reliable, maintainable change with clear business value.
March 2025
1 Commits • 1 Features
Mar 1, 20252025-03 Monthly Summary for apache/impala: Focused on feature delivery around Iceberg integration in local catalog mode. Key outcomes include a refactor that decouples IcebergTable.getPartialInfo() from internal hdfsTable_, and moves the creation of TPartialPartitionInfo from tables to partitions, aligning with unpartitioned HDFS table behavior. This enhances consistency, maintainability, and user-facing behavior in local catalog scenarios. No major bug fixes were recorded this month; the emphasis was on delivering a reliable, maintainable change with clear business value.
January 2025
3 Commits • 2 Features
Jan 1, 2025January 2025 monthly highlights for apache/impala focusing on reliability, memory efficiency, and write-path performance for Iceberg-based workloads on HDFS. Key features delivered include memory-optimized update/merge paths for Iceberg on HDFS by enabling partition-by-partition writes with inputIsClustered = true, accompanied by regression tests to validate the fix. Major bugs fixed center on preventing memory accumulation in HDFS WRITER during UPDATE and MERGE, reducing OOM risk. Additionally, performance improvements were achieved by skipping redundant updates through extra predicates in the WHERE clause for Iceberg and Kudu, significantly reducing write amplification when many rows already have the target values. Overall impact includes lower memory pressure on clusters, higher write throughput, and improved stability for update-heavy workloads. Technologies/skills demonstrated include Iceberg and Kudu integration, memory optimization techniques, regression testing, and targeted SQL UPDATE optimizations.
3 Commits • 2 Features
Jan 1, 2025January 2025 monthly highlights for apache/impala focusing on reliability, memory efficiency, and write-path performance for Iceberg-based workloads on HDFS. Key features delivered include memory-optimized update/merge paths for Iceberg on HDFS by enabling partition-by-partition writes with inputIsClustered = true, accompanied by regression tests to validate the fix. Major bugs fixed center on preventing memory accumulation in HDFS WRITER during UPDATE and MERGE, reducing OOM risk. Additionally, performance improvements were achieved by skipping redundant updates through extra predicates in the WHERE clause for Iceberg and Kudu, significantly reducing write amplification when many rows already have the target values. Overall impact includes lower memory pressure on clusters, higher write throughput, and improved stability for update-heavy workloads. Technologies/skills demonstrated include Iceberg and Kudu integration, memory optimization techniques, regression testing, and targeted SQL UPDATE optimizations.
January 2025
December 2024
1 Commits
Dec 1, 2024December 2024 monthly summary: Stabilized Iceberg integration tests for Apache Impala by addressing a race condition in parallel test execution. Implemented unique per-run iceberg.table_identifier to isolate test tables, eliminating parallel AlreadyExistsException and flaky failures. This work enhances CI reliability, accelerates feedback, and strengthens overall data lake support in Impala.
December 2024
1 Commits
Dec 1, 2024December 2024 monthly summary: Stabilized Iceberg integration tests for Apache Impala by addressing a race condition in parallel test execution. Implemented unique per-run iceberg.table_identifier to isolate test tables, eliminating parallel AlreadyExistsException and flaky failures. This work enhances CI reliability, accelerates feedback, and strengthens overall data lake support in Impala.
November 2024
2 Commits
Nov 1, 2024In 2024-11, focused on stability and correctness for Iceberg integration in Apache Impala, delivering two critical bug fixes that reduce test flakiness and prevent orphaned data/files in concurrent scenarios. These changes enhance CI reliability and transactional safety for Iceberg-backed workflows, demonstrating strong expertise in concurrency, data integrity, and test infrastructure.
2 Commits
Nov 1, 2024In 2024-11, focused on stability and correctness for Iceberg integration in Apache Impala, delivering two critical bug fixes that reduce test flakiness and prevent orphaned data/files in concurrent scenarios. These changes enhance CI reliability and transactional safety for Iceberg-backed workflows, demonstrating strong expertise in concurrency, data integrity, and test infrastructure.
November 2024
September 2024
1 Commits
Sep 1, 20242024-09 monthly summary for apache/impala: Implemented stability improvements in the sorter to prevent DCHECK crashes and ensure predictable memory-limited behavior under high load. By enforcing max_sort_run_size and updating test_sort.py memory limits, we reduced crash risk and increased test reliability, contributing to more stable query performance in memory-constrained environments. This work reduces production risk and aligns with reliability and performance objectives.
September 2024
1 Commits
Sep 1, 20242024-09 monthly summary for apache/impala: Implemented stability improvements in the sorter to prevent DCHECK crashes and ensure predictable memory-limited behavior under high load. By enforcing max_sort_run_size and updating test_sort.py memory limits, we reduced crash risk and increased test reliability, contributing to more stable query performance in memory-constrained environments. This work reduces production risk and aligns with reliability and performance objectives.
Activity
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Quality Metrics
Correctness94.6%
Maintainability93.4%
Architecture92.0%
Performance88.0%
AI Usage20.0%
Skills & Technologies
Programming Languages
C++FlatBuffersJavaPythonSQLThriftXML
Technical Skills
API DesignAPI developmentBackend DevelopmentC++Catalog ManagementCode RefactoringData ManagementData WarehousingDatabase ManagementDatabase OptimizationDatabase TestingDistributed SystemsHDFSIcebergIceberg Table Format
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