- Postgres Recognized Contributor - View Recognition
Features, Bug fix and patch review. - PostgreSQL ACE(China PostgreSQL Association).
- Greenplum Team (2019-2022, Pivotal/VMware)
Greenplum Committer & Main author of Greenplum Streaming Server (GPSS). - Apache Cloudberry Major Contributor & PPMC
Founding member of Cloudberry Database, which has contributed to the development of Apache Cloudberry.
Contributed to almost every component of the system, such as planner, exetutor, storage, distributed transaction, etc.
Main maintainer of Apache Cloudberry. A significant portion of the development work was completed before the project was
open-sourced.
Principal/ Sole author of many significant features: Parallel Query, AQUMV(Answer Query Using Materialized Views),
Dynamic Tables and etc. Critical bug fixes and much more.
Critical commits:
- Add support for LIKE in CREATE FOREIGN TABLE
- Detect redundant GROUP BY columns using UNIQUE indexes
- Disallow setting MAX_PARTITION_BUFFERS to less than 2
- Remove useless LIMIT_OPTION_DEFAULT value from LimitOption
- Provide FORCE_NULL * and FORCE_NOT_NULL * options for COPY FROM
- Remove code handling FORCE_NULL and FORCE_NOT_NULL for COPY TO
- Fix ordering issue with WAL operations in GIN fast insert path
- Avoid misbehavior when hash_table_bytes < bucket_size.
Some of critical fixes:
- Fix several DistributedTransaction related issues (#13810)
- Optimize MPP FDW LIMIT/OFFSET push down when there is NULL/0. (#17246)
- Fix incorrect result replicated table union all distributed table when gp_enable_direct_dispatch is off.
- Fix gp_toolkit.__gp_aocsseg_history crash on non-aocs tables.
- Fix gpconfig ssh retry undefined param issue. (#15283)
Sole Author, automatically answer query using the results of Materialized Views, Dynamic Tables and Incremental Materialized views in planner.
- Answer Query Using Materialized Views
- Maintain Data Status of Materialized Views for Partitioned Tables.
- Optimize Materialized View Status Maintenance for Partitioned Tables
- Optimize MV invalidation overhead using reference counting.
- [Answer Query Using Materialized Views] Support ORDER BY in origin query
- [Answer Query Using Materialized Views] Support GROUP BY, GROUPING SETS, ROLLUP, CUBE in origin query.
- [Answer Query Using Materialized Views] Support HAVING clause in origin query
- [Answer Query Using Materialized Views] Compute Aggregations on Materialized Views.
- [AQUMV] Support DISTINCT clause on origin query.
- [Answer Query Using Materialized Views] Support Postgres special grammar DISTINCT ON clause on origin query.
- [Answer Query Using Materialized Views] Support LIMIT/OFFSET/FETCH clause on origin query.
- Fast path to REFRESH materialized view.
- [AQUMV] Answer Aggregation Query Directly.
- Maintain materialized view data status.
- [AQUMV]Allow to use normal materialized views to answer query.
- [AQUMV] Extend AQUMV to support materialized views on partitioned tables.
- Refactor Extend Protocol in libpq for Binary Data Handling
- [AQUMV] Store view query in gp_matview_aux for view matching.
- [AQUMV] Directly compute queries from materialized views with GROUP BY.
Principal Author, Design and implement the architecture of Parallel Query in Greenplum/Apache Cloudberry based on Postgres’ parallel codes.
- New locus: HashWorkers, SegmentGeneralWorkers.
- Locus compatible for parallel join including: Parallel Hash/Nestloop/Merge Join, Parallel-aware Hash Join. Parallel inner, left, anti, semi join.
- Append Only (AO) table’s Parallel SeqScan.
- Append Only Column Orientation(AOCS) table’s Parallel SeqScan.
- Parallel Create Table AS of AppendOnly table storage.
- Parallel Refresh Materialized Views of AO/AOCO storage.
- Explain(locus): show locus info of each plan node.
- Insert into multiple segfiles for AO/AOCS table.
- Parallel DEDUP_SEMI and DEDUP_SEMI_REVERSE Join.
- Make UNION Parallel.
- Parallel DISTINCT plan of multi-stage.
- Parallel-oblivious Hash Left Anti Semi (Not-In) Join
- Implement Parallel-aware Hash Left Anti Semi (Not-In) Join
- Fix wrong results of Left Anti Semi (Not-In) Join
- Add motionhazard to the outer side of parallel aware join.(fix flaky incorrect results of agg)
- Refactor cdbpath_motion_for_parallel_join() by outer join inner style
- Open proper AO/AOCS segment files according to data volume
- Fix AO/AOCS insertDesc memory issue
- Fix segfilecount of AO/AOCO when bulk insertion: COPY
- [Feature] Dynamic Table.
- Let Replicated locus join with others(Results of writeable CTE on replicated table Join with others)
- Enable SingleQE join with SegmentGeneralWorkers
- Implement 3-phase aggregation with DEDUP HashAgg for DISTINCT.
- Optimize DISTINCT, ORDER BY and DISTINCT ON when Aggregation without Group By.
- 第三位中国成员！CloudberryDB 核心开发者张明礼入选 PostgreSQL Contributor 名单
- PostgreSQL 16 中国贡献者专访：张明礼
- PostgreSQL全球开发组公布 “New PostgreSQL Contributors”
- PostgreSQL 15发布 HashData贡献关键力量
