GSoC 2015

This page is for collecting ideas for future Summer of Code projects.

Accepted Projects

1. Improve the performance of "ALTER TABLE .. SET LOGGED / UNLOGGED" statement
2. Refining Simulated Annealing approach for query optimization
3. Sequential disk access during VACUUM for GiST

Project Ideas

Project ideas are to be added here by community members.

Core

• UPDATE ... RETURNING OLD link
• Add RETURNING to DDL (CREATE, ALTER, DROP) and possibly DCL (GRANT, REVOKE) link
• Allow different datatypes to be sliced differently, when TOASTed link
• Sequential disk access during VACUUM for GiST/GIN
• Support for microvacuum for GiST
• Parallel GIN build using background workers
• Implement WAL logging for hash indexes
• Indexing prolonged geometrical objects (i.e. boxes, circles, polygons, not points) with SP-GiST by mapping to 4d-space.
• Make index selection sublinear. Useful for index partitioning (vs table partitioning).
• Optimization- add to the join removal code the ability to remove joins to tables when the join is on a foreign key column (where all entries must exist in the parent anyway)
• Optimization- Check the set of conditionals on a WHERE clause against CHECK constraints on the table being queried and remove any conditionals which *must* be true due to the CHECK constraints
• Investigate the HashJoin code- specifically, review cases where the larger table is hashed instead of the smaller, test making NTUP_PER_BUCKET variable, etc.
• Improve plpgsql error checking- look at existing discussions around GUCs which can be set to increase the warnings that plpgsql throws.
• per-function temp tables (or some kind of scoping for temp tables when used inside of plpgsql code)
• date_trunc() supporting intervals
• Modify the postgres_fdw to allow a server to be defined as "autocommit" or similar- to allow for autonomous transactions
• Modify plpgsql to complain about unused variables
• Comments for function parameters
• Finally clause for pl/pgsql exception handling
• Foreign keys for arrays link PATCH
• Invent an async interface for the Append() node to use, allowing a way to parallelize queries across multiple remote FDWs or local tablespaces.
• Implement a way to store/re-use the constraint exclusion analysis results for an inheiritence-based partition setup
• Modify snapshot export to also export lock info, to avoid deadlocks between parallel pg_dump and concurrent DDL
• PL/PgSQL x++; x+= 2; operators.
• bytea '&' and '|' operators which returns a bytea, written efficiently in C by stepping through the bytea's in chunks, perhaps.

Extensions

• extending JDBC_FDW to support qual pushdown and/or writeable foreign tables API.

Project Admins

• Thom Brown
• David Fetter
• Kevin Grittner

2015 Mentors

Mentors volunteered who have been active on -hackers list:

• Alexander Korotkov
• Alvaro Herrera
• Andreas Scherbaum
• Andrew Dunstan
• Ashutosh Bapat
• Atri Sharma
• Stephen Frost