Tag: query

Feed: Planet MySQL; Author: Frederic Descamps; On this article, I will show you how to migrate your wordpress database from the MariaDB on CentOS to the real MySQL. Why migrating to MySQL 8.0 ? MySQL 8.0 brings a lot of new features. These features make MySQL database much more secure (like new authentication, secure password policies and management, …) and fault tolerant (new data dictionary), more powerful (new redo log design, less contention, extreme scale out of InnoDB, …), better operation management (SQL Roles, instant add columns), many (but really many!) replication enhancements and native group replication… and finally many ... Read More

Feed: Planet MySQL; Author: MySQL Performance Blog; PREVIOUS POST If you are using Galera replication, you know that schema changes may be a serious problem. With its current implementation, there is no way even a simple ALTER will be unobtrusive for live production traffic. It is a fact that with the default TOI alter method, Percona XtraDB Cluster (PXC) cluster suspends writes in order to execute the ALTER in the same order on all nodes. For factual data structure changes, we have to adapt to the limitations, and either plan for a maintenance window, or use pt-online-schema-change, where interruptions should ... Read More

Feed: Planet MySQL; Author: Tony Darnell; Adding a replicated MySQL database instance using a Group Replication server as the source March 25, 2019 Leave a comment You say you want a Replication? One of the best features of MySQL is the ability to use MySQL‘s built-in database replication feature to automatically replicate data from one server (source/master) to another (slave/replica). Group Replication was added in MySQL 5.7 as a way to provide a high-availability solution using a new variation of MySQL replication. (In some earlier posts, I explained how to setup Group Replication using three MySQL database servers and how to ... Read More

Feed: Featured Blog Posts - Data Science Central. Author: satyajit maitra. BigQuery is Google’s serverless, highly scalable, enterprise data warehouse designed to make all your data analysts productive at an unmatched price-performance. Because there is no infrastructure to manage, you can focus on analyzing data to find meaningful insights using familiar SQL without the need for a database administrator. Analyze all your data by creating a logical data warehouse over managed, columnar storage, as well as data from object storage and spreadsheets. Build and operationalize machine learning solutions with simple SQL. Easily and securely share insights within your organization and beyond as ... Read More

Feed: Neo4j Graph Database Platform. Author: Jocelyn Hoppa. Graph algorithms provide the means to understand, model and predict complicated dynamics such as the flow of resources or information, the pathways through which contagions or network failures spread, and the influences on and resiliency of groups.This blog series is designed to help you better utilize graph analytics and graph algorithms so you can effectively innovate and develop intelligent solutions faster using a graph database like Neo4j.Last week we once again looked at Community Detection algorithms, with a focus on the Louvain Modularity algorithm.This week we wrap up our exploration of Community ... Read More

Feed: Teradata Blog. Have you ever gone on an unscripted road trip?  You know your desired destination, but you decide on the details of your route as you travel along. Is the scenic by-way jammed with tourists?  Is there road work up ahead?  No problem. You just adapt to the unexpected conditions and consider alternate ways to get to your destination.After going on a few road trips where everything was planned in advance, I have learned the hard way that it is better to stay flexible and open to adapting to the conditions that arise along the way. Taking a ... Read More

Feed: Planet PostgreSQL.  System catalogs? Pgpool-II needs to access PostgreSQL's system catalogs whenever it recognizes tables in user's query.  For example, Pgpool-II has to know whether the table in question is a temporary table or not. If it's a temporary table, then the query using the temporary table must be routed to the primary PostgreSQL, rather than one of standby PostgreSQL servers because  PostgreSQL does not allow to create temporary tables on standby servers. Another use case is converting the table name to OID (Object Identifier). OIDs are unique keys for objects managed in PostgreSQL's system catalogs.Same thing can be ... Read More

Feed: Blog – ArangoDB. Author: Willi Goesgens. This is an update of the 2016 blog post How to put ArangoDB to Spartan-Mode. A lot of things have changed in the last years. We moved our API implementation from JavaScript to C++. ArangoDB now has a new (default) storage engine, namely RocksDB instead of MMFiles. RocksDB is a great storage engine. However, it also trades memory for speed. If you start with the default configuration you might end up with using much more memory for ArangoDB than expected. Therefore let’s focus on our new storage engine, and make a configuration to ... Read More

Feed: Planet MySQL; Author: Ahmed Bouchefra; Laravel 5.8 is recently released with many improvements so we'll be learning, throughout this tutorial how to create an example CRUD application from scratch. The application we'll be building is a simple CRM with a MySQL database. You can see this Upgrade Guide for instructions on how to upgrade an existing web application from Laravel 5.7 to Laravel 5.8 Tutorial Prerequisites This tutorial has some prerequisites You have at least PHP 7.1.3 installed on your development machine, Working experience of PHP. The OpenSSL, PDO, Mbstring, Tokenizer, XML, Ctype, JSON and BCMath PHP extensions installed ... Read More

Feed: What's New. Starting today, you can now use fleet indexing to count the number of devices that match a given query. For example, let’s say your devices write their firmware version and battery level to the Device Shadow (where dynamic attributes are stored), and their model number to the Registry (where static attributes are stored). Now, you can write a query to count the number of devices running a particular version of firmware, or to count the number of devices of a particular model number. With these figures, you can then determine the percentage of devices running the latest ... Read More