apache/cloudberry
Nov 2021 – Dec 2021
2 Months active
Languages Used
CSQL
Technical Skills
C programmingPostgreSQLdatabase managementunit testingConcurrencyDatabase Management
Zhang Hao
PROFILE
Zhang Hao
Worked on the apache/cloudberry repository to enhance disk quota management by implementing relfilenode-based size calculation for database relations, enabling accurate resource tracking and quota enforcement. Developed user-defined functions in C and SQL for table size checks, integrated with quota controls, and introduced unit tests to ensure correctness. Improved reliability by adding a shared-memory relation cache for uncommitted tables, robust locking for concurrency, and cache-based size computation covering both committed and temporary objects. Addressed deadlock-prone paths, hardened size calculations, and stabilized test environments, resulting in more accurate quota reporting and a more robust, maintainable disk quota subsystem for PostgreSQL.
Overall Statistics
Feature vs Bugs
67%Features
Repository Contributions
10Total
Bugs
1
Commits
10
Features
2
Lines of code
2,092
Activity Months2
Your Network
212 peopleShared Repositories
212
erchuanMember
Wenkang ZhangMember
zhangwenchaoMember
zhaoMember
Alexander KondakovMember
Andrey SokolovMember
Ashwin AgrawalMember
Adam LeeMember
Adam LeeMember
Work History
December 2021
9 Commits • 1 Features
Dec 1, 2021December 2021 — Apache Cloudberry (Performance & Reliability Monthly Summary) Key features delivered: - Disk quota relation cache and size reporting improvements: introduced a shared-memory relation cache to track uncommitted relations, added robust locking for thread-safety, and implemented a cache-based size computation that covers both committed and uncommitted tables. This enables accurate quota reporting across temporary and permanent objects and resolves edge-cases in AO size calculations. Major bugs fixed: - Fixed deadlock-prone paths and improved cache traversal: acquired shared locks safely when traversing the relation_cache and ensured proper removal of committed relations from the cache. - Size calculation hardening: added calculate_table_size() to compute any table’s size without blocking on catalog access, fixed AO/CTAS size calculations, and corrected removal of stale cache entries after VACUUM FULL. - Test stability and cleanup: eliminated test artifacts that could affect subsequent tests and fixed test expectations to maintain deterministic outcomes. Overall impact and accomplishments: - Improved quota accuracy for both committed and uncommitted/temporary tables, enabling better resource governance, capacity planning, and cost controls. - More robust data lifecycle handling in the disk quota subsystem, reducing risk of over- or under-reporting and improving reliability for operators. - Strengthened test suite stability, providing faster feedback and higher confidence in deployments. Technologies and skills demonstrated: - Shared memory data structures, locking and concurrency control, and deadlock avoidance in a PostgreSQL extension. - Catalog-safe size calculations and avoidance of blocking catalog accesses during quota computations. - Test hygiene, automation, and regression testing for disk quota features. Key commits (highlights): c8def2d98218aca09b466c91b1549164de3b1fa8; 631f6736e2fdf21117fc7f0b2cb17b0000298602; b57fbf662dbdeba091f1b3eb9fb01b4e34a560ea; a86c2d3fccc4c69f44e91168a04bd7f8d8b90e53; ff47b1ea6485124b015c33d5061ebaaed2c57682; ada901cb0818c38864767aafa6a9cf5956ae65a8; a9723e95af457b970f2ef979c8730ef573682ed4; 520fcd1895dbde58095f1737421663faa1169967; 3c3a6fd11557b733163a0be42fc282b2d87645ce
9 Commits • 1 Features
Dec 1, 2021December 2021 — Apache Cloudberry (Performance & Reliability Monthly Summary) Key features delivered: - Disk quota relation cache and size reporting improvements: introduced a shared-memory relation cache to track uncommitted relations, added robust locking for thread-safety, and implemented a cache-based size computation that covers both committed and uncommitted tables. This enables accurate quota reporting across temporary and permanent objects and resolves edge-cases in AO size calculations. Major bugs fixed: - Fixed deadlock-prone paths and improved cache traversal: acquired shared locks safely when traversing the relation_cache and ensured proper removal of committed relations from the cache. - Size calculation hardening: added calculate_table_size() to compute any table’s size without blocking on catalog access, fixed AO/CTAS size calculations, and corrected removal of stale cache entries after VACUUM FULL. - Test stability and cleanup: eliminated test artifacts that could affect subsequent tests and fixed test expectations to maintain deterministic outcomes. Overall impact and accomplishments: - Improved quota accuracy for both committed and uncommitted/temporary tables, enabling better resource governance, capacity planning, and cost controls. - More robust data lifecycle handling in the disk quota subsystem, reducing risk of over- or under-reporting and improving reliability for operators. - Strengthened test suite stability, providing faster feedback and higher confidence in deployments. Technologies and skills demonstrated: - Shared memory data structures, locking and concurrency control, and deadlock avoidance in a PostgreSQL extension. - Catalog-safe size calculations and avoidance of blocking catalog accesses during quota computations. - Test hygiene, automation, and regression testing for disk quota features. Key commits (highlights): c8def2d98218aca09b466c91b1549164de3b1fa8; 631f6736e2fdf21117fc7f0b2cb17b0000298602; b57fbf662dbdeba091f1b3eb9fb01b4e34a560ea; a86c2d3fccc4c69f44e91168a04bd7f8d8b90e53; ff47b1ea6485124b015c33d5061ebaaed2c57682; ada901cb0818c38864767aafa6a9cf5956ae65a8; a9723e95af457b970f2ef979c8730ef573682ed4; 520fcd1895dbde58095f1737421663faa1169967; 3c3a6fd11557b733163a0be42fc282b2d87645ce
December 2021
November 2021
1 Commits • 1 Features
Nov 1, 2021Concise monthly summary for 2021-11 focusing on business value and technical achievements in the apache/cloudberry repo.
November 2021
1 Commits • 1 Features
Nov 1, 2021Concise monthly summary for 2021-11 focusing on business value and technical achievements in the apache/cloudberry repo.
Activity
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Quality Metrics
Correctness92.0%
Maintainability86.0%
Architecture88.2%
Performance86.0%
AI Usage22.0%
Skills & Technologies
Programming Languages
CSQL
Technical Skills
C programmingConcurrencyDatabase ManagementMemory ManagementPostgreSQLSQLSQL scriptingbug fixingdatabase managementsystem optimizationtestingunit testing
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