PG-Development on Vonng

PostgreSQL Convention 2024

rh@vonng.com (Ruohang Feng) — Mon, 27 Nov 2023 00:00:00 +0000

No rules, no standards. Some developer conventions for PostgreSQL 16.

AI Large Models and Vector Database PGVector

rh@vonng.com (Ruohang Feng) — Wed, 10 May 2023 00:00:00 +0000

This article focuses on vector databases hyped by AI, introduces the basic principles of AI embeddings and vector storage/retrieval, and demonstrates the functionality, performance, acquisition, and application of the vector database extension PGVECTOR through a concrete knowledge base retrieval case study.

Implementing Advanced Fuzzy Search

rh@vonng.com (Ruohang Feng) — Fri, 05 Mar 2021 00:00:00 +0000

How to implement relatively complex fuzzy search logic in PostgreSQL?

Frontend-Backend Communication Wire Protocol

rh@vonng.com (Ruohang Feng) — Tue, 12 Nov 2019 00:00:00 +0000

Understanding the TCP protocol used for communication between PostgreSQL server and client, and printing messages using Go

Transaction Isolation Level Considerations

rh@vonng.com (Ruohang Feng) — Tue, 12 Nov 2019 00:00:00 +0000

PostgreSQL actually has only two transaction isolation levels: Read Committed and Serializable

CDC Change Data Capture Mechanisms

rh@vonng.com (Ruohang Feng) — Wed, 12 Jun 2019 00:00:00 +0000

Change Data Capture is an interesting ETL alternative solution.

Locks in PostgreSQL

rh@vonng.com (Ruohang Feng) — Tue, 11 Jun 2019 00:00:00 +0000

Snapshot isolation does most of the heavy lifting in PG, but locks still matter. Here’s a practical guide to table locks, row locks, intention locks, and pg_locks.

O(n2) Complexity of GIN Search

rh@vonng.com (Ruohang Feng) — Fri, 12 Apr 2019 00:00:00 +0000

When GIN indexes are used to search with very long keyword lists, performance degrades significantly. This article explains why GIN index keyword search has O(n^2) time complexity.

GeoIP Geographic Reverse Lookup Optimization

rh@vonng.com (Ruohang Feng) — Sat, 07 Jul 2018 00:00:00 +0000

A common requirement in application development is GeoIP conversion - converting source IP addresses to geographic coordinates or administrative divisions (country-state-city-county-town-village)

PostgreSQL Trigger Usage Considerations

rh@vonng.com (Ruohang Feng) — Sat, 07 Jul 2018 00:00:00 +0000

Detailed understanding of trigger management and usage in PostgreSQL

PostgreSQL Development Convention (2018 Edition)

rh@vonng.com (Ruohang Feng) — Wed, 20 Jun 2018 00:00:00 +0000

Without rules, there can be no order. This article compiles a development specification for PostgreSQL database principles and features, which can reduce confusion encountered when using PostgreSQL.

Efficient Administrative Region Lookup with PostGIS

rh@vonng.com (Ruohang Feng) — Wed, 06 Jun 2018 00:00:00 +0000

How to efficiently solve the typical reverse geocoding problem: determining administrative regions based on user coordinates.

KNN Ultimate Optimization: From RDS to PostGIS

rh@vonng.com (Ruohang Feng) — Wed, 06 Jun 2018 00:00:00 +0000

Ultimate optimization of KNN problems, from traditional relational design to PostGIS

Distinct On: Remove Duplicate Data

rh@vonng.com (Ruohang Feng) — Fri, 06 Apr 2018 00:00:00 +0000

Use Distinct On extension clause to quickly find records with maximum/minimum values within groups

Function Volatility Classification Levels

rh@vonng.com (Ruohang Feng) — Fri, 06 Apr 2018 00:00:00 +0000

PostgreSQL functions have three volatility levels by default. Proper use can significantly improve performance.

Implementing Mutual Exclusion Constraints with Exclude

rh@vonng.com (Ruohang Feng) — Fri, 06 Apr 2018 00:00:00 +0000

Exclude constraint is a PostgreSQL extension that can implement more advanced and sophisticated database constraints.

Implementing Cache Synchronization with Go and PostgreSQL

rh@vonng.com (Ruohang Feng) — Thu, 03 Aug 2017 00:00:00 +0000

Cleverly utilizing PostgreSQL’s Notify feature, you can conveniently notify applications of metadata changes and implement trigger-based logical replication.

Auditing Data Changes with Triggers

rh@vonng.com (Ruohang Feng) — Fri, 09 Jun 2017 00:00:00 +0000

Sometimes we want to record important metadata changes for audit purposes. PostgreSQL triggers can conveniently solve this need automatically.

Building an ItemCF Recommender in Pure SQL

rh@vonng.com (Ruohang Feng) — Wed, 05 Apr 2017 00:00:00 +0000

Five minutes, PostgreSQL, and the MovieLens dataset—that’s all you need to implement a classic item-based collaborative filtering recommender.

UUID Properties, Principles and Applications

rh@vonng.com (Ruohang Feng) — Sun, 06 Nov 2016 00:00:00 +0000

UUID properties, principles and applications, and how to manipulate UUIDs using PostgreSQL stored procedures.