everly-gif/gsoc-2022-final-report.md

## gsoc-2022-final-report.md

      
    Raw
  

              gsoc-2022-final-report.md
            
          
GSoC 2022 - Final Project Report

The following report summarizes my work done during Google Summer of Code 2022 with the Apache Software Foundation.
Contributor Details


Name: Everly Precia Suresh
Github Username: everly-gif
Organization: The Apache Software Foundation
Project Title: Solve unsupported Postgres SQL about alter statement for ShardingSphere Parser

About the Project


    The ecosystem to transform any database into a distributed database system.


Apache ShardingSphere is positioned as a Database Plus, and aims at building a standard layer and ecosystem above heterogeneous databases. It focuses on how to reuse existing databases and their respective upper layer, rather than creating a new database. The goal is to minimize or eliminate the challenges caused by underlying database fragmentation. ShardingSphere parser engine is the core of ShardingSphere, It helps users parse a SQL to get the AST (Abstract Syntax Tree) and visit this tree to get SQLStatement (Java Object). At present, this parser engine can handle SQLs for MySQL, PostgreSQL, SQLServer, openGauss and Oracle. However, there are still many statements under these dialects that are not supported yet.


Therefore this project proposes to Solve unsupported Postgres sql about ALTER statements for ShardingSphere Parser and also proofread and optimize the grammar wherever needed.


More details: https://shardingsphere.apache.org/document/current/en/reference/sharding/parse/
Goals

Implementation of properly written and optimized grammar, visit methods, new corresponding SQL cases, and proper support for PostgreSQL ALTER Statements ensuring there are no exceptions in SQL Parsing for the following statements.


ALTER OPERATOR
ALTER SERVER


ALTER POLICY
ALTER STATISTICS


ALTER PUBLICATION
ALTER SUBSCRIPTION


ALTER ROUTINE
ALTER TABLE


ALTER RULE
ALTER TEXT SEARCH


ALTER SCHEMA
ALTER TRIGGER


ALTER SEQUENCE
ALTER TYPE


ALTER VIEW


Approach and Workflow


Proofread through DDLStatement.g4 to analyze existing grammars and optimize them.
Write grammar for unsupported ALTER Statements referring to the official PostgreSQL documentation.
Implement visit methods for the statements.
Add new corresponding SQL cases in SQL Cases and expected parsed results in Expected Statement XML.
Run SQLParserParameterizedTest and UnsupportedSQLParserParameterizedTest to make sure there are no exceptions.


    Background: SQL Parsing


Pull Requests and Issues

Community Bonding period

Includes Community Issues and PRs.

⊙ #17736: Support ShardingSphere parser of openGauss sql
✔ #17856: Support parsing ALTER SYNONYM in openGauss
✔ #17861: Support parsing CREATE SYNONYM in openGauss
✔ #17862: Support parsing DROP SYNONYM in openGauss
✔ #17911: Support parsing CREATE DIRECTORY in openGauss
✔ #17960: Support parsing ALTER DIRECTORY in openGauss
✔ #17974: Support parsing DROP DIRECTORY in openGauss
✔ #17986: Support parsing CREATE CAST in openGauss
✔ #18003: Support parsing DROP CAST in openGauss
✔ #18032: Support parsing ALTER RULE in openGauss
✔ #18034: Support parsing DROP RULE in openGauss
✔ #18038: Support parsing CHECKPOINT in openGauss
✔ #18086: Support parsing ALTER TYPE in openGauss
✔ #18088: Support parsing DROP TYPE in openGauss
✔ #18163: Support parsing CREATE PUBLICATION in openGauss
✔ #18172: Support parsing DROP PUBLICATION in openGauss

Coding Period

Includes PRs and Issues related to GSoC project

⊙ #17848: [ GSoC 2022 ] Solve unsupported Postgres sql about ALTER statement for ShardingSphere Parser
✔ #18322: Support parsing ALTER OPERATOR in PostgreSQL
✔ #18371: Support Parsing ALTER POLICY in PostgreSQL
✔ #18427: Support Parsing ALTER PUBLICATION in PostgreSQL
✔ #18607: Support Parsing ALTER ROUTINE in PostgreSQL
✔ #18784: Support Parsing ALTER RULE in PostgreSQL
✔ #19291: Proofread ALTER SEQUENCE grammar + add test cases
✔ #19311: Add testcase to support parsing of ALTER SCHEMA in PostgreSQL
✔ #19395: Support parsing ALTER SERVER in PostgreSQL
✔ #19842: Support parsing ALTER STATISTICS in PostgreSQL
✔ #19932: Support Parsing ALTER SUBSCRIPTION in PostgreSQL
✔ #20333: Support parsing ALTER TEXT SEARCH in PostgreSQL
✔ #20611: Support Parsing ALTER TRIGGER in PostgreSQL
✔ #20618: Support Parsing ALTER TYPE in PostgreSQL
✔ #20774: Enhance support for ALTER TABLE and ALTER VIEW in PostgreSQL

Result

Intended Goals were met during the standard coding period, SQL parsing for the statements were achieved.
Future Scope

Now that the SQL parsing of these statements are completed, we can focus on configuring read-write splitting feature and implementing the executions of the Parsed SQL.
Acknowledgement

The past 3 months have challenged me to learn and grow. I had a fruitful summer coding and interacting with the Apache ShardingSphere community. This truly has been one of a kind experience. I would like to show my gratitude to my amazing mentors for guiding me throughout this journey and Google for organizing such a beneficial program.
Additional Links


Progress Tracker
Project Link
Slack Workspace
ALTER OPERATOR	ALTER SERVER
ALTER POLICY	ALTER STATISTICS
ALTER PUBLICATION	ALTER SUBSCRIPTION
ALTER ROUTINE	ALTER TABLE
ALTER RULE	ALTER TEXT SEARCH
ALTER SCHEMA	ALTER TRIGGER
ALTER SEQUENCE	ALTER TYPE
ALTER VIEW