Author: MariaDB Knowledge Database

Feed: MariaDB Knowledge Base Article Feed. Author: . Basic idea Consider a query with a WHERE clause: WHERE col1=col2 AND ... the WHERE clause will compute to true only if col1=col2. This means that in the rest of the WHERE clause occurrences of col1 can be substituted with col2 (with some limitations which are discussed in the next section). This allows the optimizer to infer additional restrictions. For example: WHERE col1=col2 AND col1=123 allows to infer a new equality: col2=123 WHERE col1=col2 AND col1 < 10 allows to infer that col2<10. Identity and comparison substitution There are some limitations to ... Read More

Feed: MariaDB Knowledge Base Article Feed. Author: . Homebrew 패키지 매니저를 이용해서 MariaDB Server를 macOS (이전 Mac OS X) 설치할 수 있습니다. MariaDB Server는 미리 컴파일된 Homebrew "bottle" 패키지로 이용 가능하며, 소스 빌드가 필요 없어 시간을 절약해줄 수 있습니다. Homebrew 설치 후에는 MariaDB Server 는 다음과 같이 설치 가능합니다. brew install mariadb 설치 후에는 다음으로 MariaDB Server를 시작합니다.: mysql.server start MariaDB Server 자동 시작하려면 다음과 같이 Homebrew 서비스 기능을 이용할 수 있습니다. (이 서비스 기능은 launchd 의 launchctl 유틸리티를 이용합니다) : brew services start mariadb MariaDB Server 시작후에는 사용자 계정으로 로그인하면 됩니다.: mysql 또는 루트 계정으로 로그인할 수도 있습니다.: sudo ... Read More

Feed: MariaDB Knowledge Base Article Feed. Author: . ERBuilder Data Modeler is a GUI data modeling tool that allows developers to visualize, design, and model databases by using entity relationship diagrams and automatically generates the most popular SQL databases. Generate and share the data Model documentation with your team. Optimize your data model by using advanced features such as test data generation, schema compare, and schema synchronization Supported DBMS include: MariaDB MySQL Microsoft SQL Server Microsoft Azure SQL database Oracle PostgreSQL SQLite Firebird Amazon Redshift Amazon RDS Key features: Visual data modeling Forward and Reverse Engineering Data Model Validation Data ... Read More

Feed: MariaDB Knowledge Base Article Feed. Author: . MaxGUI is the new browser based tool for configuring and managing MaxScale. It is a more user friendly and intuitive to use companion to the command line tool maxctrl. In order to enable MaxGUI, at least the following parameters must be set in the MaxScale configuration file: admin_ssl_key, admin_ssl_cert. Check Configuration-Guide for details. To prevent the use of MaxGUI, set admin_gui to false in the configuration file. Once enabled, MaxGUI can be accessed from https://127.0.0.1:8989/. MaxGUI cannot be used without providing credentials. MaxGUI uses the same credentials as maxctrl, so by default, ... Read More

Feed: MariaDB Knowledge Base Article Feed. Author: . Overview The KafkaCDC module reads data changes in MariaDB via replication and converts them into JSON objects that are then streamed to a Kafka broker. DDL events (CREATE TABLE, ALTER TABLE) are streamed as JSON objects in the following format (example created by CREATE TABLE test.t1(id INT)): { "namespace": "MaxScaleChangeDataSchema.avro", "type": "record", "name": "ChangeRecord", "table": "t2", // name of the table "database": "test", // the database the table is in "version": 1, // schema version, incremented when the table format changes "gtid": "0-3000-14", // GTID that created the current version of the ... Read More

Feed: MariaDB Knowledge Base Article Feed. Author: . Overview The mirror router is designed for data consistency and database behavior verification during system upgrades. It allows statement duplication to multiple servers in a manner similar to that of the Tee filter with exporting of collected query metrics. For each executed query the router exports a JSON object that describes the query results and has the following fields: Key Description query The executed SQL if an SQL statement was executed command The SQL command session The connection ID of the session that executed the query query_id Query sequence number, starts from ... Read More

Feed: MariaDB Knowledge Base Article Feed. Author: . As a Java developer and author of a Java blog, I frequently receive requests from Java programmers around the world asking how they can improve. In the past, I have shared my 10 tips for becoming a better programmer, and every tip in this article is still true, but since it's a new year, I decided to write down some new tips so that Java programmers are improving, improving their knowledge of Java programming and increasing their value for future career growth. So without wasting time, let's see my nine ideas for ... Read More

Feed: MariaDB Knowledge Base Article Feed. Author: . Syntax INET6 Description The INET6 data type is intended for storage of IPv6 addresses, as well as IPv4 addresses assuming conventional mapping of IPv4 addresses into IPv6 addresses. Both short and long IPv6 notation are permitted, according to RFC-5952. Values are stored as a 16-byte fixed length binary string, with most significant byte first. Storage engines see INET6 as BINARY(16). Clients see INET6 as CHAR(39) and get text representation on retrieval. The IPv4-compatible notation is considered as deprecated. It is supported for compatibility with the INET6_ATON function, which also understands this format ... Read More

Feed: MariaDB Knowledge Base Article Feed. Author: . They are based on files that do not match the relational format but often represent hierarchical data. CONNECT can handle JSON, INI-CFG, XML, and some HTML files. The way it is done is different from what MySQL or PostgreSQL does. In addition to including in a table some column values of a specific data format (JSON, XML) to be handled by specific functions, CONNECT can directly use JSON, XML or INI files that are produced by other applications, and this is the table definition that describes where and how the contained information ... Read More

Feed: MariaDB Knowledge Base Article Feed. Author: . To enable the REST feature with binary distributions of MariaDB, the function calling the cpprestsdk package is not included in CONNECT, thus allowing CONNECT normal operation when the cpprestsdk package is not installed. Therefore, it must be compiled separately as a library (so or dll) that will be loaded by CONNECT when needed. This library will contain only one file shown here: /************* Restget C++ Program Source Code File (.CPP) *************/ /* Adapted from the sample program of the Casablanca tutorial. */ /* Copyright Olivier Bertrand 2019. */ /***********************************************************************/ #include <cpprest/filestream.h> #include ... Read More