Tag: mysql

  1. Updated

    Setup Scalable WordPress Sites on Kubernetes

    Category: DevOps, Web Development

    This article is about how to deploy a scalable WordPress site on Google Kubernetes Engine.

  2. Updated

    Import MySQL database but ignore specific tables

    Category: Database, DevOps

    You could just exclude tables you do not need.

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    MySQL system error codes

    Category: Database, DevOps

    Print all OS error codes and MySQL error codes using the perror command.

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    Convert utf8 tables to utf8mb4 in MySQL

    Category: Database

    Don't blindly copy-paste this!

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    Create a custom migration in Django

    Category: Database, Python

    ALTER TABLE app_repostarring CHANGE repo_description repo_description VARCHAR(191) CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci;

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    Locking and MVCC in MySQL InnoDB 鎖機制與多版本並發控制

    Category: Database

    最近在研究 MySQL 5.6 / 5.7 InnoDB storage engine 的 Transaction、Locking 和 Multi-Version Concurrency Control (MVCC) 機制,基本上只討論 Isolation level 是 REPEATABLE READ 或 READ COMMITTED 的情況,這一篇是過程中記錄下來的筆記。

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    Django's get_or_create() may raise IntegrityError but subsequent get() raises DoesNotExist

    Category: Database, Python, Web Development

    get_or_create() 拋出 IntegrityError 但是接著 get() 一次卻會是 DoesNotExist,以上的錯誤常常會發生在 MySQL 的 isolation level 是 REPEATABLE READ 的情況下。MySQL 默認採用 REPEATABLE READ(而 PostgreSQL 預設是 READ COMMITTED)。

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    Transaction isolation levels in MySQL

    Category: Database

    A non-repeatable read occurs, when during the course of a transaction, a row is retrieved twice and the values within the row differ between reads.