Category: My SQL
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Table Level Replication in MySQL on Windows OS
Hello guys, Hope you are going great. In this article, we are going to talk about configuring MySQL replication between two servers. Here there will be one master and one slave server. It’s simple setup there are basically 6 major steps which are below… Step 1 –> ============================================================================ /*Take dump of the tables which we…
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CAP Theorem
In theoretical computer science, the CAP theorem, also named Brewer’s theorem after computer scientist Eric Brewer, states that it is impossible for a distributed data store to simultaneously provide more than two out of the following three guarantees: Consistency Every read receives the most recent write or an error. Availability Every request receives a (non-error)…
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Azure Azure SQL Database Azure SQL Database Backup and Recovery Backup Tools for SQL Server DBA Worries Continued DBMS Concepts DBMS Concepts DBMS Concepts High Availability L1 DBA Monitoring My SQL Performance Tuning PostgreSQL Security SQL Scripting SQL Server
Important SQL Server Scripts…
Restore Progress Check… ========================================================================== DECLARE @DBName VARCHAR(64) = ‘ODS’ DECLARE @ErrorLog AS TABLE([LogDate] CHAR(24), [ProcessInfo] VARCHAR(64), [TEXT] VARCHAR(MAX)) INSERT INTO @ErrorLog EXEC master..sp_readerrorlog 0, 1, ‘Recovery of database’, @DBName INSERT INTO @ErrorLog EXEC master..sp_readerrorlog 0, 1, ‘Recovery completed’, @DBName SELECT TOP 1 @DBName AS [DBName] ,[LogDate] ,CASE WHEN…
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Serialized Dictionary Information (SDI)
In addition to storing metadata about database objects in the data dictionary, MySQL stores it in serialized form. This data is referred to as serialized dictionary information (SDI). InnoDB stores SDI data within its tablespace files. NDBCLUSTER stores SDI data in the NDB dictionary. Other storage engines store SDI data in .sdi files that are created for a given table in the table’s…
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Removal of File-based Metadata Storage
In previous MySQL releases, dictionary data was partially stored in metadata files. Issues with file-based metadata storage included expensive file scans, susceptibility to file system-related bugs, complex code for handling of replication and crash recovery failure states, and a lack of extensibility that made it difficult to add metadata for new features and relational objects.…
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Transactional Storage of Dictionary Data
The data dictionary schema stores dictionary data in transactional (InnoDB) tables. Data dictionary tables are located in the mysql database together with non-data dictionary system tables. Data dictionary tables are created in a single InnoDB tablespace named mysql.ibd, which resides in the MySQL data directory. The mysql.ibd tablespace file must reside in the MySQL data directory and its name cannot be modified…
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InnoDB Engine
InnoDB is a general-purpose storage engine that balances high reliability and high performance. In MySQL 8.0, InnoDB is the default MySQL storage engine. Unless you have configured a different default storage engine, issuing a CREATE TABLE statement without an ENGINE= clause creates an InnoDB table. Key Advantages of InnoDB
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InnoDB Multi-Versioning
InnoDB is a multi-versioned storage engine: it keeps information about old versions of changed rows, to support transactional features such as concurrency and rollback. This information is stored in the tablespace in a data structure called a rollback segment (after an analogous data structure in Oracle). InnoDB uses the information in the rollback segment to perform the undo operations needed in a…
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MySQL Physical (Raw) Vs Logical Backups
Physical backups consist of raw copies of the directories and files that store database contents. This type of backup is suitable for large, important databases that need to be recovered quickly when problems occur. Logical backups save information represented as logical database structure (CREATE DATABASE, CREATE TABLE statements) and content (INSERT statements or delimited-text files). This type of…
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MySQL Full Vs Incremental Backups
A full backup includes all data managed by a MySQL server at a given point in time. An incremental backup consists of the changes made to the data during a given time span (from one point in time to another). MySQL has different ways to perform full backups, such as those described earlier in this…
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MySQL Full Versus Point-in-Time (Incremental) Recovery
A full recovery restores all data from a full backup. This restores the server instance to the state that it had when the backup was made. If that state is not sufficiently current, a full recovery can be followed by recovery of incremental backups made since the full backup, to bring the server to a…
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