ClickHouse是俄罗斯的Yandex于2016年开源的列式存储数据库(DBMS),使用C++语言编写,主要用于在线分析处理查询(OLAP),能够使用SQL查询实时生成分析数据报告。 OLAP(On-Line Analytical Processing)翻译为联机分析处理,专注于分析处理,从对数据库操作来看,OLAP是对数据的查询; OLTP(on-line transaction processing)翻译为联机...
Perfect answer:This is the document type (doc-type) declaration that we always put as the first line in HTML files. You might think that this information is redundant because the browser already knows that the MIME type of the response istext/html; butin the Netscape/Internet Explorer days, ...
The map projection of the earth in the middle of the picture shows an azimuthal equidistant projection with the South Pole in the center. This is unusual, as such projections typically put the North Pole in the center. But, in this case, may be necessary for the map rotation and the corr...
UTMTerm String, FromTag String, HasGCLID UInt8, RefererHash UInt64, URLHash UInt64, CLID UInt32, YCLID UInt64, ShareService String, ShareURL String, ShareTitle String, ParsedParams Nested(Key1 String, Key2 String, Key3 String, Key4 String, Key5 String, ValueDouble Float64), IslandID ...