Webyog Glossary

A

ACID

The four properties that guarantee reliable database transaction processing. Atomicity ensures all operations in a transaction succeed or all are rolled back. Consistency ensures the…

Learn More →

Advisor

In MONyog, one of 600+ built-in rules that continuously analyse MySQL server health metrics and flag potential issues — such as a too-small buffer pool,…

Learn More →

Agentless Monitoring

A monitoring approach that collects metrics directly over the MySQL protocol or SSH without installing any agent software on the monitored server. MONyog is fully…

Learn More →

Amazon Aurora

A MySQL and PostgreSQL-compatible relational database built for the cloud by AWS. Aurora delivers up to 5x the throughput of standard MySQL while maintaining full…

Learn More →

Amazon RDS (Relational Database Service)

Amazon's managed relational database service that automates hardware provisioning, database setup, patching, and backups for MySQL, MariaDB, and Aurora. MONyog uses the RDS REST API…

Learn More →

Analyze Table

A MySQL statement that updates the table's index statistics, helping the query optimiser make better decisions about which indexes to use. Running ANALYZE TABLE after…

Learn More →

API (Application Programming Interface)

A defined interface that lets software applications communicate with each other. In MySQL monitoring, APIs are how MONyog integrates with PagerDuty, Slack, and SNMP management…

Learn More →

Asynchronous Replication

The default MySQL replication mode where the primary server commits a transaction without waiting for any replica to confirm receipt. Offers the lowest write latency…

Learn More →

Auto Increment

A MySQL column attribute (AUTO_INCREMENT) that automatically generates a unique sequential integer for each new row. Commonly used for primary key columns to ensure every…

Learn More →

B

Binlog (Binary Log)

MySQL's binary log records every change (INSERT, UPDATE, DELETE, DDL) made to the database. It is the foundation of MySQL replication and enables point-in-time recovery…

Learn More →

Buffer Pool

InnoDB's in-memory cache that stores frequently accessed table data and index pages. A correctly sized buffer pool (often 70-80% of available RAM) dramatically reduces disk…

Learn More →

Bulk Insert

Loading large volumes of data using a single INSERT statement with multiple value rows, or tools like LOAD DATA INFILE. Bulk inserts are far more…

Learn More →

C

Capacity Planning

The practice of anticipating future database resource needs — disk space, memory, CPU, connections — before they become bottlenecks. MONyog's historical trending charts help DBAs…

Learn More →

Client/Server Architecture

MySQL follows a client/server model: the mysqld daemon process runs on the server, managing databases and processing queries; client programs (SQLyog, phpMyAdmin, application connectors) connect…

Learn More →

CloudWatch

Amazon CloudWatch is AWS's monitoring and observability service. MONyog integrates with the CloudWatch API to display RDS OS-level metrics — CPU utilisation, memory usage, disk…

Learn More →

Clustered Index

An index that determines the physical storage order of data in a table. In InnoDB, the primary key is always the clustered index. Every row's…

Learn More →

Composite Index

An index on two or more columns. MySQL can use a composite index for queries that filter on the leftmost prefix of the indexed columns.…

Learn More →

Configuration Management

The practice of tracking and auditing changes to MySQL global system variables. MONyog's configuration management feature records every change to MySQL global variables and lets…

Learn More →

Connection Pool

A cache of database connections maintained by an application or middleware so connections can be reused rather than opened and closed for every request. Reduces…

Learn More →

Covering Index

An index that contains all the columns a query needs, so MySQL can satisfy the query entirely from the index without accessing the base table…

Learn More →

CPU Utilisation

The percentage of the server's CPU capacity being consumed by MySQL processes. High CPU utilisation often indicates inefficient queries or an underpowered server. MONyog surfaces…

Learn More →

CRUD (Create, Read, Update, Delete

The four fundamental database operations: INSERT, SELECT, UPDATE, and DELETE. CRUD is the basis of virtually every application's interaction with a relational database.

Learn More →

CTE (Common Table Expression)

A named temporary result set defined with the WITH clause in MySQL 8.0+. CTEs make complex queries more readable and support recursive queries (WITH RECURSIVE)…

Learn More →

D

Data Archiving

Moving infrequently accessed but historically important data out of active production tables into cheaper storage or archive tables. Keeps production tables lean and fast. SQLyog's…

Learn More →

Data Audit

The process of tracking who accessed or modified data in a MySQL database, and when. Essential for PCI-DSS, HIPAA, and GDPR compliance. MONyog monitors for…

Learn More →

Data Compression

Reducing the on-disk footprint of MySQL table and index data. InnoDB supports row-level compression (ROW_FORMAT=COMPRESSED) and transparent page compression. Reduces storage costs and can improve…

Learn More →

Data Dictionary

MySQL 8.0 introduced a transactional data dictionary stored in InnoDB tables, replacing the file-based .frm files of earlier versions. Stores all metadata about schemas, tables,…

Learn More →

Data Encryption at Rest

Encrypting the physical files that store MySQL data on disk. InnoDB supports transparent tablespace encryption (MySQL 5.7.11+). A compliance requirement for PCI-DSS, HIPAA, and GDPR…

Learn More →

Data Integrity

The accuracy, consistency, and reliability of data stored in a MySQL database. Enforced through primary keys, foreign keys, NOT NULL constraints, CHECK constraints (MySQL 8.0.16+),…

Learn More →

Data Migration

Moving data from one MySQL instance, schema, or data format to another. SQLyog's Data Synchronisation and Schema Synchronisation tools automate the comparison and transfer steps,…

Learn More →

Data Modelling

The process of designing the logical and physical structure of a database — defining entities, attributes, relationships, and constraints. Good data modelling choices (normalisation level,…

Learn More →

Data Retention Policy

A defined rule specifying how long data must be kept in a MySQL database before it can be deleted or archived. Driven by legal obligations…

Learn More →

Data Synchronisation

The process of comparing and aligning data between two MySQL databases to ensure both are consistent. SQLyog's Data Synchronisation feature lets DBAs visually compare row-level…

Learn More →

Data Types

MySQL supports a rich set of data types: numeric (INT, BIGINT, FLOAT, DOUBLE, DECIMAL), string (CHAR, VARCHAR, TEXT), date/time (DATE, DATETIME, TIMESTAMP, YEAR), and JSON.…

Learn More →

Database Change Management

The process of planning, reviewing, tracking, and deploying changes to database schemas, stored procedures, and configuration in a controlled way. SQLyog's schema comparison and synchronisation…

Learn More →

Database Diagnostics

The practice of systematically identifying the root cause of MySQL performance problems — slow queries, lock waits, high CPU, replication lag — using EXPLAIN, the…

Learn More →

Database IDE

A GUI tool that combines a SQL editor, schema browser, query builder, visual explain plan, and debugging tools into a single interface. SQLyog is Webyog's…

Learn More →

DBA (Database Administrator)

The professional responsible for installing, configuring, monitoring, performance-tuning, securing, and backing up a MySQL database environment. DBAs use SQLyog for schema management and query development,…

Learn More →

DDL (Data Definition Language)

SQL statements that define or modify database structure: CREATE, ALTER, DROP, RENAME, and TRUNCATE. DDL statements in MySQL cause an implicit commit and cannot be…

Learn More →

Deadlock

A situation where two or more transactions are each waiting for the other to release a lock. InnoDB automatically detects deadlocks and rolls back the…

Learn More →

Denormalisation

Intentionally introducing redundancy into a database schema to improve read query performance — for example, storing a pre-computed column that would otherwise require a JOIN…

Learn More →

Disk I/O

The rate and volume of read/write operations between MySQL and physical or virtual storage. High disk I/O is a primary bottleneck when the working set…

Learn More →

DML (Data Manipulation Language)

SQL statements that manipulate data within existing tables: SELECT, INSERT, UPDATE, and DELETE. DML statements can be wrapped in transactions and rolled back.

Learn More →

Dump

An export of a MySQL database's structure and/or data to a file, typically created with mysqldump or SQLyog's built-in export. Used for backups, migrations, and…

Learn More →

E

Error Log

MySQL's error log records server startup and shutdown events, critical errors, and warnings. It is the first place to look when diagnosing MySQL crashes or…

Learn More →

ETL (Exact, Transfer, Load)

The process of extracting data from source systems, transforming it into the target format, and loading it into a destination database. SQLyog's data export/import and…

Learn More →

Event Scheduler

MySQL's built-in job scheduler that executes SQL events at defined times or intervals. Useful for automated maintenance tasks like purging old records or refreshing summary…

Learn More →

EXPLAIN

A MySQL statement that shows the query execution plan — which indexes are used, how tables are joined, the estimated row count, and join type.…

Learn More →

F

Failover

The automated or manual process of switching database traffic from a failed primary server to a healthy replica or standby. MONyog monitors replication topology and…

Learn More →

Fault Tolerance

A system's ability to continue operating correctly in the presence of component failures. In MySQL, achieved through redundant architectures: replication, automatic failover, and Galera/Group Replication.

Learn More →

Foreign Key

A constraint that enforces referential integrity between two tables by ensuring that a column's value in one table matches a value in a specified column…

Learn More →

Full-Text Index

A special MySQL index type that enables efficient text search using MATCH AGAINST syntax. Supports natural language and boolean search modes. Available in InnoDB (from…

Learn More →

G

Galera Cluster

A synchronous multi-master replication solution for MySQL and MariaDB that provides virtually synchronous writes across all nodes, automatic node provisioning, and no replica lag. All…

Learn More →

General Query Log

A MySQL log that records every client connection and SQL statement received by the server. Useful for auditing and debugging. MONyog can surface General Query…

Learn More →

Global Variables

MySQL server-wide configuration parameters set with SET GLOBAL or in my.cnf/my.ini. MONyog's configuration management tracks changes to global variables over time so DBAs can correlate…

Learn More →

Google Cloud SQL

Google Cloud's fully managed relational database service supporting MySQL, PostgreSQL, and SQL Server. MONyog supports monitoring Google Cloud SQL MySQL instances, and SQLyog can connect…

Learn More →

GROUP_REPLICATION

MySQL Group Replication (MySQL 5.7.17+) is a plugin that enables multi-master, virtually synchronous replication with automatic failover. It is the foundation of MySQL InnoDB Cluster.

Learn More →

GTID (Global Transaction Identifier)

A unique identifier assigned to each committed transaction on a MySQL server (introduced in MySQL 5.6). GTIDs simplify replication setup, failover, and recovery by making…

Learn More →

H

HAProxy

A high-performance open-source load balancer commonly used in front of MySQL clusters to distribute connections across primary and replica nodes. Performs health checks and can…

Learn More →

High Availability (HA)

A design strategy that ensures a database system remains operational with minimal downtime, typically by combining replication, automatic failover, and load balancing. Common MySQL HA…

Learn More →

Histogram

A MySQL 8.0+ statistics object that captures the distribution of values in a column, enabling the optimiser to better estimate result set sizes for nonindexed…

Learn More →

Horizontal Scaling

Adding more servers (read replicas, shards) to distribute database load. MySQL read replicas are the most common form of horizontal scaling for read-heavy workloads.

Learn More →

Hot Backup

A database backup taken while the MySQL server is running and handling live traffic, without locking tables. SQLyog's scheduled backup feature can automate logical hot…

Learn More →

Hybrid Cloud

A deployment model mixing on-premises servers, private cloud, and public cloud infrastructure. Both SQLyog and MONyog support hybrid cloud MySQL environments from a single management…

Learn More →

I

Incident Management

The process of detecting, responding to, and resolving service disruptions or degraded database performance. MONyog integrates with PagerDuty to automatically create incidents when MySQL advisors…

Learn More →

Incremental Backup

A backup strategy that captures only the data changed since the last full or incremental backup. MySQL incremental backups are commonly implemented using binary log…

Learn More →

Index

A data structure (typically a B-tree) that allows MySQL to find rows matching a WHERE clause or ORDER BY condition without scanning the entire table.…

Learn More →

Index Cardinality

The estimated number of unique values in an indexed column. High cardinality makes an index very selective and effective. MySQL's SHOW INDEX output shows cardinality,…

Learn More →

Information Schema

A read-only virtual database (information_schema) built into MySQL that provides metadata about all databases, tables, columns, indexes, foreign keys, and user privileges. SQLyog uses information_schema…

Learn More →

InnoDB

The default and most widely used MySQL storage engine. Provides full ACID compliance, row-level locking, foreign key support, crash recovery, and the MVCC model for…

Learn More →

InnoDB Buffer Pool Size

The innodb_buffer_pool_size configuration variable controls how much RAM InnoDB uses to cache data and indexes. For a dedicated MySQL server, setting this to 70-80% of…

Learn More →

InnoDB Cluster

MySQL's integrated high-availability solution combining MySQL Group Replication, MySQL Router (for transparent client failover), and MySQL Shell. Provides multi-master replication, automatic failover, and a management…

Learn More →

IT Infrastructure Monitoring

The broad practice of monitoring all components of an IT environment — servers, networks, storage, and databases. MONyog integrates into existing infrastructure monitoring stacks via…

Learn More →

J

JDBC (Java Database Connectivity)

A Java API that defines how Java applications connect to relational databases. MySQL provides the official Connector/J JDBC driver. Application servers use JDBC connection pools…

Learn More →

JOIN

A SQL clause that combines rows from two or more tables based on a related column. Types include INNER JOIN, LEFT JOIN, RIGHT JOIN, and…

Learn More →

JSON Data Type

MySQL 5.7.8+ introduced a native JSON data type with automatic validation and optimised storage, along with JSON functions (JSON_EXTRACT, JSON_SET, etc.) and virtual columns to…

Learn More →

L

Latency

The time between sending a query and receiving the first byte of the response. MONyog tracks query latency trends and alerts when response times cross…

Learn More →

Load Balancing

Distributing incoming database connections across multiple MySQL servers to prevent any single server from becoming a bottleneck. Implemented with HAProxy, ProxySQL, or cloud-native load balancers.

Learn More →

Lock Contention

A condition where multiple transactions compete for the same row-level or table-level locks, causing one or more to wait. High lock contention degrades throughput and…

Learn More →

Long-Running Query

A SQL query that takes significantly longer than expected to execute. MONyog's real-time query monitoring flags long-running queries so DBAs can investigate and optimise them.

Learn More →

M

MariaDB

A community-developed, open-source relational database forked from MySQL in 2009. MariaDB is highly compatible with MySQL, adds performance improvements and new features, and is supported…

Learn More →

max_connections

A MySQL server variable that sets the maximum number of simultaneous client connections allowed. MONyog's advisors alert when connection usage approaches the max_connections ceiling, helping…

Learn More →

Metadata

In MySQL, structural information about database objects — table names, column definitions, index structures, foreign key relationships — stored in information_schema and performance_schema. MySQL's query…

Learn More →

MONyog

Webyog's agentless MySQL performance monitoring tool. MONyog tracks 600+ health advisors, real-time query and session data, replication status, and custom dashboards — all without installing…

Learn More →

Multi-Master Replication

A replication configuration where two or more MySQL servers each accept write operations and replicate changes to each other. Common in Galera Cluster and Group…

Learn More →

Multi-Source Replication

A MySQL replication topology where a single replica receives binary log events from multiple primary servers simultaneously, merging data from several sources. MONyog's replication topology…

Learn More →

MVCC (Multi-Version Concurrency Control)

InnoDB's mechanism for allowing consistent reads without blocking writes. Each transaction sees a snapshot of the database at the time the transaction started, preventing dirty…

Learn More →

MyISAM

A legacy MySQL storage engine offering fast read performance and fulltext search, but lacking ACID transaction support, row-level locking, and foreign keys. Largely replaced by…

Learn More →

MySQL

The world's most popular open-source relational database management system. MySQL is the database at the centre of Webyog's toolset — managed via SQLyog and monitored…

Learn More →

mysqld

The MySQL server daemon process that handles all database operations — accepting connections, parsing queries, managing transactions, enforcing security, and writing to storage engines. mysqld…

Learn More →

mysqldump

MySQL's built-in command-line utility for creating logical backups — exporting database contents as SQL statements to a text file. SQLyog provides a GUI wrapper for…

Learn More →

N

Normalisation

The process of structuring a relational database to reduce data redundancy and improve integrity, following normal forms (1NF, 2NF, 3NF, BCNF). Over-normalisation can hurt query…

Learn More →

NULL

A special marker in SQL that represents a missing, unknown, or inapplicable value. NULL comparisons require IS NULL or IS NOT NULL. NULLs in indexed…

Learn More →

O

ODBC (Open Database Connectivity)

A standard API for connecting applications to relational databases. MySQL provides a Connector/ODBC driver, enabling tools like Microsoft Excel, Power BI, and legacy applications to…

Learn More →

OLAP (Online Analytical Processing)

Workloads characterised by complex, long-running queries over large datasets — aggregations, GROUP BY operations, window functions. MySQL supports OLAP workloads through read replicas and partitioning.

Learn More →

OLTP (Online Transaction Processing)

A workload characterised by many short, concurrent transactions — inserts, updates, and deletes — typical of web applications, e-commerce, and CRM systems. MySQL with InnoDB…

Learn More →

Online DDL

MySQL's ability to execute ALTER TABLE statements without fully locking the table for reads and writes. Introduced in MySQL 5.6 with the ALGORITHM=INPLACE option, allowing…

Learn More →

Optimize Table

A MySQL statement that defragments an InnoDB table, reclaims unused space left by deleted rows, and updates table statistics. For large tables with frequent DELETEs,…

Learn More →

Optimizer Hints

Inline SQL directives that instruct the MySQL query optimiser to use a specific index, join algorithm, or execution strategy. Optimizer hints give DBAs fine-grained control…

Learn More →

P

PagerDuty

A digital incident management and on-call alerting platform. MONyog integrates with PagerDuty via an integration key, automatically creating and routing incidents when MySQL health advisors…

Learn More →

Partitioning

Dividing a large table into smaller, physically separate pieces based on a partition key. MySQL partition pruning can dramatically speed up queries that filter on…

Learn More →

Performance Schema

A MySQL feature (database: performance_schema) that provides instrumented, low-level monitoring data — statement execution counts, wait events, memory usage — directly within MySQL. MONyog leverages…

Learn More →

Point-in-Time Recovery

Restoring a MySQL database to the exact state it was in at a specific moment, using a full backup plus binary log replay. Essential for…

Learn More →

Prepared Statement

A precompiled SQL template sent to the MySQL server once, then executed multiple times with different parameter values. Prepared statements prevent SQL injection, reduce query…

Learn More →

Primary Key

A column or set of columns that uniquely identifies each row in a table. In InnoDB, the primary key is the clustered index. Choosing a…

Learn More →

Privilege System

MySQL's built-in access control mechanism that grants or restricts what operations each user can perform on databases, tables, columns, and stored routines. Privileges are stored…

Learn More →

Processlist

The output of SHOW PROCESSLIST, which lists all currently active threads on the MySQL server. MONyog continuously polls the processlist to surface long-running and blocked…

Learn More →

ProxySQL

A high-performance open-source MySQL proxy providing connection multiplexing, read/write splitting, query routing, and failover. Widely used in high-availability MySQL architectures to abstract the topology from…

Learn More →

Q

QPS (Queries Per Second)

The number of SQL queries MySQL executes per second — a primary measure of database workload and throughput. MONyog tracks QPS in real time across…

Learn More →

Query Execution Plan

The detailed set of steps MySQL's optimiser chooses to execute a query, including which indexes to use, join order, and access methods. Viewed with EXPLAIN…

Learn More →

Query Profiling

Measuring the time MySQL spends in each stage of query execution. MySQL's SHOW PROFILES and SQLyog's Query Profiler identify exactly where time is spent in…

Learn More →

Query Tuning

The iterative process of rewriting SQL queries or adjusting index strategies to reduce execution time. Starts with EXPLAIN analysis to identify full scans and inefficient…

Learn More →

R

RDBMS (Relational Database Management System)

A database system that organises data into tables with rows and columns, enforces relationships using foreign keys, and uses SQL for data definition and manipulation.…

Learn More →

Read Replica

A MySQL server that replicates data from a primary server and handles read-only queries, offloading read traffic from the primary. MONyog monitors replication lag on…

Learn More →

Redo Log

InnoDB's write-ahead log that records every change made to data pages before they are written to disk. The redo log enables crash recovery — if…

Learn More →

Relay Log

On a MySQL replica, the relay log stores binary log events received from the primary but not yet applied. The SQL thread reads and applies…

Learn More →

Replication

The process of copying and synchronising data from a MySQL source (primary) server to one or more replica servers using the binary log. Used for…

Learn More →

Replication Lag

The delay between when a transaction commits on the primary and when it is applied on a replica. MONyog continuously monitors replication lag and alerts…

Learn More →

Resource Contention

A condition where multiple MySQL queries or threads compete for the same limited resource — CPU cycles, I/O bandwidth, memory, or row locks — causing…

Learn More →

Row-Level Locking

InnoDB's default locking granularity, which locks individual rows rather than entire tables. Allows much higher concurrency than table-level locking because transactions only block access to…

Learn More →

S

Schema

In MySQL, 'schema' is synonymous with 'database' — a named container of tables, views, stored procedures, and other objects. Schema design decisions around data types,…

Learn More →

Schema Synchronisation

The process of comparing the structure of two MySQL databases and generating ALTER statements to make the target match the source. SQLyog's schema synchronisation feature…

Learn More →

Semi-Synchronous Replication

A MySQL replication mode where the primary waits for at least one replica to acknowledge receipt of the binary log event before returning success to…

Learn More →

Slow Query Log

A MySQL log that records queries taking longer than long_query_time seconds. Analysing the slow query log with tools like pt-query-digest is a fundamental DBA practice…

Learn More →

SMTP (Simple Mail Transfer Protocol)

The standard protocol for sending email. MONyog's email notification integration uses SMTP to send alerts when MySQL health monitors cross warning or critical thresholds.

Learn More →

SNMP Trap

A network notification sent from a monitored device to an SNMP management system when a threshold is breached. MONyog can send SNMP traps in addition…

Learn More →

SQL Diagnostic Manager for MySQL (SQLDM for MYSQL)

The full product name for MONyog — Webyog's MySQL monitoring and diagnostics platform. Provides agentless monitoring, 600+ advisors, realtime query analytics, and replication topology visualisation.

Learn More →

SQL Injection

A critical web security vulnerability where an attacker inserts malicious SQL code into an application input. Prevention requires parameterised queries (prepared statements) and strict input…

Learn More →

SQLyog

Webyog's powerful MySQL GUI for Windows. Combines a visual query builder, schema editor, automated backup scheduler, data comparison and sync, and query profiler — giving…

Learn More →

SSH Tunnelling

An encrypted tunnel through which MySQL connections are forwarded, allowing secure remote database access without exposing the MySQL port to the internet. SQLyog and MONyog…

Learn More →

SSL/TLS (Secure Sockets Layer/Transport Layer Security)

Encryption protocols for securing data in transit between MySQL clients and the server. MySQL supports SSL/TLS connections via certificates. Enabling SSL prevents credentials and query…

Learn More →

Stored Procedure

A named, precompiled set of SQL statements stored in the MySQL database and executed as a unit. Stored procedures reduce network round-trips, centralise business logic…

Learn More →

Subquery

A SELECT statement nested inside another SQL statement. Correlated subqueries can be slow on large tables; rewriting them as JOINs or CTEs often produces better…

Learn More →

sys Schema

A collection of views, stored procedures, and functions (introduced in MySQL 5.7.7) built on top of performance_schema to make its raw data more human-readable. Simplifies…

Learn More →

Syslog

A standard protocol and service for centralised system log collection on Linux/Unix servers. MONyog can write alerts and notifications to the local Syslog, enabling MySQL…

Learn More →

T

Table Lock

A lock that prevents any other session from reading from or writing to a table while a statement is executing. Used by MyISAM and some…

Learn More →

Table Statistics

MySQL's internal estimates of table size, index cardinality, and value distribution used by the query optimiser. Stale statistics are a common cause of bad query…

Learn More →

Temporary Table

A table created with CREATE TEMPORARY TABLE that exists only for the duration of the current MySQL session. Internal implicit temporary tables (created by MySQL…

Learn More →

Thread

MySQL handles each client connection with a dedicated thread. MONyog's Threads view shows each running thread, its query, and its wait state, using SHOW FULL…

Learn More →

Throughput

The number of queries or transactions a MySQL server processes per unit of time. MONyog tracks QPS in real time across all connected servers to…

Learn More →

TPS (Transaction Per Second)

The number of database transactions committed per second. A drop in TPS without a drop in QPS often signals increasing lock contention or replication problems.

Learn More →

Transaction

A unit of work that groups one or more SQL statements that must all succeed or all fail together. Transactions in InnoDB support COMMIT, ROLLBACK,…

Learn More →

Triggers

Stored programs that automatically execute in response to INSERT, UPDATE, or DELETE events on a table. Enforce business rules at the database level but can…

Learn More →

U

UNDO Log

InnoDB's internal log of the 'before' image of modified data, used to roll back transactions and provide consistent reads via MVCC. A large UNDO log…

Learn More →

UTF-8

MySQL's utf8mb4 character set is the correct implementation of full Unicode UTF-8, supporting all Unicode code points including 4-byte characters (emoji, supplementary characters). The older…

Learn More →

V

View

A saved SELECT query stored in the database as a named virtual table. Views simplify complex queries, provide a security layer by restricting column access,…

Learn More →

Visual Analytics

The use of charts, graphs, and interactive dashboards to explore and interpret database performance data. MONyog's custom dashboards provide visual analytics over MySQL metrics —…

Learn More →

W

Wait Events

MySQL Performance Schema instrumentation that records what a thread is waiting for — a row lock, an I/O operation, a mutex, or a condition variable.…

Learn More →

WAL (Write-Ahead Logging)

A technique where changes are written to a sequential log (InnoDB's redo log) before being applied to data pages. WAL guarantees durability and enables crash…

Learn More →

Window Functions

SQL functions (ROW_NUMBER, RANK, LAG, LEAD, SUM OVER, etc.) introduced in MySQL 8.0 that perform calculations across a set of rows related to the current…

Learn More →

X

XA Transactions

MySQL's implementation of the X/Open XA standard for distributed transaction processing. XA allows a single ACID transaction to span multiple databases or resource managers, coordinated…

Learn More →

Z

Zero-Downtime Migration

A database migration strategy that keeps the source database fully operational during the move. Techniques include gh-ost, Percona Online Schema Change, or dual-write patterns. SQLyog's…

Learn More →
Copyright © 2026 Webyog Inc. All Rights Reserved.