Clickhouse database adds, deletes, and modifies fields in a single machine and a cluster, replicates table data in batches, performs regular addition, deletion, modification, and query operations, and ReplacingMergeTree and SummingMergeTree data consistency.
1 Introduction
Clickhouse is an OLAP open source database produced by Yandex (online search engine). It is written in C++. Yandex initially used MySQL as its data storage and analysis engine solution. In 2011, MySQL stored more than 580 billion rows of data. Although Yandex has made a lot of additional optimizations and successfully controlled 90% of the analysis reports to be returned within 26 seconds. However, this technical solution is becoming increasingly inadequate. So Yandex developed and open sourced clickhouse. Currently, with more than 20 trillion rows of data stored, ClickHouse is able to return 90% of queries within 1 second.
This article involves some addition, deletion, modification and query operations, including databases and tables, focusing on the addition/deletion operations of fields. The content contained in it has passed the actual test.
advantage
A true columnar database with complete DBMS functions (supports DML and DDL).
Extremely high compression ratio.
The vector calculation engine supports multi-core CPU parallel computing. When executing each SQL statement, it strives to squeeze out the CPU performance and multi-core parallel processing to process large queries in parallel in the most natural way. Currently, the SSE4.2 instruction set is used to implement vectorized execution.
Multi-server distributed processing supports master-slave replication architecture. Data sharding and distributed query. In a non-shared database cluster, each node has an independent disk storage system and memory system. Business data is divided into each node according to the database model and application characteristics. Each data node passes through a dedicated network. Or commercial general networks are connected to each other, perform collaborative calculations with each other, and provide database services as a whole.
Compatible with most SQL syntax, its syntax is very similar to MySQL.
Data supports real-time updates and online queries.
Has merge trees, memory, files, interfaces and other