Planet MariaDB Server

This is part 3 of my series on using HW counters from Linux perf to explain why MySQL gets slower from 5.6 to 8.0. Refer to part 1 for an overview.What happened in MySQL 5.7 and 8.0 to put so much more stress on the memory system?tl;drIt looks like someone sprinkled magic go slower dust across most of the MySQL code because the slowdown from MySQL 5.6 to 8.0 is not isolated to a few call stacks.MySQL 8.0 uses ~1.5X more instructions/operation than 5.6. Cache activity (references, loads, misses are frequently up 1.5X or more. TLB activity (loads, misses) is frequently up 2X to… Read more

This is part 4 of my series on using HW counters from Linux perf to explain why MySQL gets slower from 5.6 to 8.0. Refer to part 1 for an overview.What happened in MySQL 5.7 and 8.0 to put so much more stress on the memory system?tl;drIt looks like someone sprinkled magic go slower dust across most of the MySQL code because the slowdown from MySQL 5.6 to 8.0 is not isolated to a few call stacks.MySQL 8.0 uses ~1.5X more instructions/operation than 5.6. Cache activity (references, loads, misses are frequently up 1.5X or more. TLB activity (loads, misses) is frequently up 2X to… Read more

This is part 2 of my series on using HW counters from Linux perf to explain why MySQL gets slower from 5.6 to 8.0. Refer to part 1 for an overview.What happened in MySQL 5.7 and 8.0 to put so much more stress on the memory system?tl;drIt looks like someone sprinkled magic go slower dust across most of the MySQL code because the slowdown from MySQL 5.6 to 8.0 is not isolated to a few call stacks.MySQL 8.0 uses ~1.5X more instructions/operation than 5.6. Cache activity (references, loads, misses are frequently up 1.5X or more. TLB activity (loads, misses) is frequently… Read more

I spend much time documenting how MySQL performance has changed over the years. After my latest round of benchmarks I looked at flamegraphs from MySQL/InnoDB during the insert benchmark. Unfortunately, I didn't see anything obvious when comparing flamegraphs for MySQL 5.6, 5.7 and 8.0. Mostly, the flamegraphs looked the same — the percentage of time in various call stacks was similar, and the call stacks were similar.So the flamegraphs look similar, but MySQL 8.0 gets less work done per second. A possible explanation is that everything gets slower, perhaps from more cache misses, so I used Linux perf to debug… Read more

When you encounter the 53300: TOO_MANY_CONNECTIONS error in PostgreSQL, it indicates that your database has reached its maximum configured limit for simultaneous connections. This can happen due to high traffic, inefficient application design, or insufficient configuration settings. […] The post Resolving PostgreSQL Error 53300: TOO_MANY_CONNECTIONS – A Comprehensive Troubleshooting and Optimization Guide appeared first on The WebScale Database Infrastructure Operations Experts in PostgreSQL, MySQL, MariaDB and ClickHouse…. Read more

As with every Galera Manager release, we consider a huge amount of features, and we always improve the UI and functionality based on your feature requests, to ensure that as a user, you’re happier, but more importantly, more efficient in production. ​ One of the biggest feature requests was to have Percona XtraDB Cluster (PXC) […]… Read more

Using eBPF (extended Berkeley Packet Filter) for troubleshooting MySQL query latency and index usage is a sophisticated technique that leverages Linux's advanced tracing capabilities. eBPF allows you to trace system and application-level metrics without significant performance overhead […] The post Advanced Troubleshooting of MySQL Query Latency and Index Usage with eBPF: Scripts and Methodologies appeared first on The WebScale Database Infrastructure Operations Experts in PostgreSQL, MySQL, MariaDB and ClickHouse…. Read more

Implementing data obfuscation in PostgreSQL to comply with the General Data Protection Regulation (GDPR) involves transforming sensitive data into a less sensitive form, a process that helps protect personal data while maintaining its usability. […] The post Implementing GDPR-Compliant Data Obfuscation in PostgreSQL: Strategies and Techniques appeared first on The WebScale Database Infrastructure Operations Experts in PostgreSQL, MySQL, MariaDB and ClickHouse…. Read more

Implementing partial indexes in PostgreSQL is an efficient way to optimize your database performance, especially when dealing with large tables with specific query patterns. Partial indexes are indexes built over a subset of a table, defined by a condition. […] The post Optimizing PostgreSQL Queries with Partial Indexes: A Step-by-Step Guide appeared first on The WebScale Database Infrastructure Operations Experts in PostgreSQL, MySQL, MariaDB and ClickHouse…. Read more

Introduction Two points in advance: A deadlock is a state in which two different transactions are no longer able to continue working because each transaction holds a lock that the other transaction would need. Because both transactions are now waiting for the other transaction to release their locks, neither transaction will release their respective locks. And that would last forever. To avoid this, the MariaDB instance intervenes and kills the transaction that has done less work. The application then receives a deadlock error message of this type: ERROR 1213 (40001): Deadlock found when trying to get lock; try restarting transaction… Read more

Introduction Two points in advance: A deadlock is a state in which two different transactions are no longer able to continue working because each transaction holds a lock that the other transaction would need. Because both transactions are now waiting for the other transaction to release their locks, neither transaction will release their respective locks. And that would last forever. To avoid this, the MariaDB instance intervenes and kills the transaction that has done less work. The application then receives a deadlock error message of this type: ERROR 1213 (40001): Deadlock found when trying to get lock; try restarting transaction… Read more

Mastering Row Locks in PostgreSQL: Ensuring Data Integrity and Performance […] The post Mastering Row Locks in PostgreSQL: Ensuring Data Integrity and Performance appeared first on The WebScale Database Infrastructure Operations Experts in PostgreSQL, MySQL, MariaDB and ClickHouse…. Read more

PostgreSQL, renowned for its robustness and versatility, often "rocks" as a database management system. However, it's not without its challenges, particularly when it comes to locking mechanisms. […] The post PostgreSQL rocks, except when it blocks: Understanding locks appeared first on The WebScale Database Infrastructure Operations Experts in PostgreSQL, MySQL, MariaDB and ClickHouse…. Read more

Dear users of MySQL 5.7 (or 8.0)! Are you interested in getting help migrating to MariaDB 10.11, the very latest long-term support release? Are you coming to Brussels for FOSDEM in February? … Continue reading "Looking for MySQL 5.7 or 8.0 guinea pigs" The post Looking for MySQL 5.7 or 8.0 guinea pigs appeared first on MariaDB.org…. Read more

Pagination in MariaDB, like in other databases, requires careful consideration of performance and consistency. Basic pagination with LIMIT and OFFSET is straightforward but might not be the best approach for large datasets due to performance issues. […] The post Optimizing Pagination Queries in MariaDB: Best Practices, Efficient Techniques, and Performance Tips appeared first on The WebScale Database Infrastructure Operations Experts in PostgreSQL, MySQL, MariaDB and ClickHouse…. Read more