The PostgreSQL community has a structured process for submitting patches and changes to the core code through a mailing list called pgadmin-hackers. This process involves creating a patch, submitting it to the mailing list, and then participating in a month-long activity called Commitfest where contributors and core staff review and discuss the patches. During Commitfest, patches are reviewed by senior experts, and if they pass review, they are committed to the master branch. The process is designed to ensure that changes are thoroughly reviewed, maintained, and improved before being released. To participate in Commitfest, individuals can submit their own patches, which should be well-documented, concise, and relevant to the community's needs. The community emphasizes the importance of collaboration, communication, and constructive feedback throughout the process.