MinervaDB Blog: Mastering WebScale Database Infrastructure

MariaDB Cache Buffer Chains: How They Are Implemented in MariaDB 11

In MariaDB 11, the cache buffer chains (CBC) implementation is part of the InnoDB storage engine. The CBC is a data structure used to manage the InnoDB buffer pool, which is a cache that stores […]

PostgreSQL Optimizer Index Caching Explained

Optimizer index caching in PostgreSQL is the process by which the database caches the index pages in memory to speed up the execution of queries. This feature helps improve the performance of queries by reducing […]

PostgreSQL Cardinality: How the Optimizer Behaves When It Is Zero

In PostgreSQL, the optimizer uses cardinality estimates to determine the most efficient execution plan for a query. Cardinality refers to the number of rows in a table or the number of rows returned by a […]

MySQL Histograms: When MySQL Ignores Them

MySQL can ignore histograms in the query optimizer when it determines that using the histograms would not provide any benefit to the query execution plan. This can occur in several cases, including: Why MySQL ignores […]

MySQL Mutex Contention: Troubleshooting Guide

Mutex contention occurs in MySQL when multiple threads attempt to access a shared resource, such as a data structure or a system resource, simultaneously. Because only one thread can access the resource at a time, […]

PostgreSQL 16 Cache Buffer Chains Demystified

Cache Buffer Chains (CBC) is a mechanism used by the PostgreSQL storage engine to manage the buffer cache and minimize the amount of disk I/O. The buffer cache is a region of memory that is […]

How to use PgBouncer for implementing connection pooling in PostgreSQL?

PgBouncer is a lightweight connection pooler for PostgreSQL. It is used to reduce the overhead of establishing a new connection to a PostgreSQL database for each client request. By pooling connections, PgBouncer can handle a […]

PostgreSQL Internals – Hacking PostgreSQL Parser

The source code for the PostgreSQL LALR(1) parser is written in C and can be found in the PostgreSQL source code repository. The main components of the parser are: To understand how the parser works, […]

PostgreSQL Freelists: Internals and Implementation

The freelists in PostgreSQL are implemented as a linked list of pages. Each page is a unit of disk space that is managed by the freelist, and its size is determined by the block size […]

PostgreSQL CPU Cache Buffers Chains Latch: How to Monitor It

The CPU Cache Buffers Chains Latch in PostgreSQL is a synchronization mechanism that protects the buffer cache data structure. The buffer cache is a pool of memory used by PostgreSQL to cache disk blocks that […]