HackerNoon

How MySQL Implicit Type Conversion Turned an Indexed Query Into a 7M-Row Scan

A missing quote made MySQL scan 7.2 million rows. Here's how EXPLAIN exposed the problem and what it taught us about safe ...
note

What to do about ERROR 1020 in MariaDB 11.8 and later: 3 ways to fix it, retrying, and locking first, plus the default ON status of innodb_snapshot_isolation (measured in ...

When innodb_snapshot_isolation is ON, if a row you are trying to rewrite (or a row you are trying to read with a lock) has been changed and committed by another connection after that baseline point in ...
iMasters

Thread pool no Percona Server: como configurar para ganhar throughput sob alta concorrência

Benchmark da Percona mostra quando thread pool multiplica o throughput do MySQL por até 18x e quando ele atrapalha. Veja os ...
note

MariaDB 11.8 以降で ERROR 1020 が出たら――ロックを先に・やり直し・OFF の直し方3つと、既定 ON の innodb_snapshot_isolation(10.6〜13.0 を Docker ...

innodb_snapshot_isolation が ON のときは、書き換えようとした行 (またはロック付きで読もうとした行)が、その基準の時点よりあとに別の接続によって変えられ、コミットされていると、ERROR 1020 でトランザクション全体を巻き戻します。OFF のときは、そのまま書き換えを通します。 ON は「黙って ...
iMasters

Como uma cláusula WHERE seletiva pode travar um cluster Galera inteiro

Um --where seletivo no pt-online-schema-change pode disparar Flow Control no Galera e travar clusters Percona XtraDB em ...