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Dolphindb distinct

WebMay 31, 2024 · The function distinct is implemented with hashmap in DolphinDB and the efficiency can be affected when processing large amount of distinct records. Whereas, … WebSep 20, 2024 · 华夏基金对市面上多家数据库进行调研测试，从性能、语言学习成本和技术服务等多方面进行综合考量，最终选择高性能时序数据库 DolphinDB。本文将分享华夏基 …

distinct — DolphinDB 2.0 documentation

Webunion/union all. New in version 2.00.9. 用于合并两个或多个 select / exec 查询的结果集。. union 会将重复的记录删去，union all 保留所有记录。. 支持在分布式查询中使用。. 注意：. union / union all 连接的 select / exec 语句必须查询相同数量的列，且对应列的类型必须能够 … WebDolphinDB database supports dynamic loading of external plugins to extend system functionality. The plug-in can be written in C++, and it needs to be compiled into ".so" … fowsia musse go fund me https://planetskm.com

Selecting distinct columns in DolphinDB with different …

WebAsk Question. DolphinDB is a high performance time series database. It is written in C++ and optimized for fast injection, storage, retrieval and analysis of time series data in fields such as quantitative finance, Internet of Things, real-time analytics, etc. DolphinDB runs extremely fast. It is also easy to use as the syntax of the ... WebApr 11, 2024 · 本系列文章将会介绍如何使用DolphinDB优雅而高效地实现量化交易策略回测。. 本文将介绍在华尔街广泛应用的多因子Alpha策略的回测。多因子模型是量化交易选股中最重要的一类模型，基本思路是找到某些和回报率最相关的指标，并根据这些指标，构建股票投资组合（做多正相关的股票，做空负相关 ... WebAug 17, 2024 · Both DolphinDB and kdb+ actually run the script in single thread even though DolphinDB community version offers up to 2 threads (not 4). DolphinDB database offers the function pcall to parallelize the execution. In DolphinDB, a single thread took 6,412 ms for calculation (250 million) while two threads took 2,938ms and four threads … black suit and sneakers

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Category:策略回测从2小时提速到1分钟，DolphinDB 助力华夏基金量化投研

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Dolphindb distinct

DolphinDB Database丨数据导入教程-爱代码爱编程

WebDolphinDB's scripting language is vector based and supports functional programming. The language is extremely expressive and effective for data manipulation and analysis. The interpretation overhead is very small. DolphinDB optimizes all built-in functions/commands from basic functions (e.g. sort) to high level functions (e.g. table joins). WebSql 获取用户名有不同大小写的用户总数,sql,sql-server,regex,count,Sql,Sql Server,Regex,Count,我有一个SQL表，其中用户名有不同的大小写，例如“ACCOUNTS\Ninja.Developer”或“ACCOUNTS\Ninja.Developer” 我想找出用户名首字母大写和姓氏首字母大写的记录数？

Dolphindb distinct

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WebDolphinDB数据库中sql语句的向量,dolphindb,Dolphindb. ... 1..5 as value) exec distinct(id) as id from t order by id. 如何从DolphinDB数据库中的SELECT语句生成向量？看起来SELECT语句总是生成一个表，即使只选择了一列 ...

WebMar 8, 2024 · Python Parser这个项目，目标就是让DolphinDB原生地支持使用Python来管理存储与计算，这样用户的学习成本就可以降至最低，而且Python Parser还将原生地支持numpy和pandas的操作。具体地说，我们自行在DolphinDB内部实现了一个Python的解释器，而且这个解释器将没有GIL的束缚 ... WebApr 10, 2013 · Note I think the following is slightly simpler: select @cols =(SELECT DISTINCT QUOTENAME(Week) + ',' from yt order by 1 FOR XML PATH('')) set @cols = SUBSTRING(@cols, 1, LEN(@cols) - 1 ... DolphinDB is a columnar high performance database. The calculation in the demo costs as low as 546 ms on a dell xps laptop (i7 cpu).

WebDolphinDB is dedicated to developing the most powerful and advanced time-series database. DolphinDB’s clients include investment banks, mutual funds, hedge funds, cryptocurrency exchanges, large ... Web下面我们将介绍如何在DolphinDB中测试动量交易策略，并计算动量交易策略的累积回报。 DolphinDB database 是一款高性能分布式时序数据库。 与其它通常的数据库不同，DolphinDB不仅可以存储和检索数据，而且具备强大的编程和分析功能，可以直接在数据库内完成策略 ...

WebApr 14, 2024 · dolphindb_conn_id: 用于指定 DolphinDB 连接，可在 connection 中设置; sql: 指定需要运行的 DolphinDB 脚本; file_path: 可以指定 DolphinDB dos 文件运行脚本 …

WebMay 24, 2024 · Hello, I Really need some help. Posted about my SAB listing a few weeks ago about not showing up in search only when you entered the exact name. I pretty … fow skillset development board sharepoint.comWebHow to use DolphinDB image. For starters, if you want to experience the DolphinDB server at a quick speed, we recommand you enter the following code on your computer: $ docker pull dolphindb/dolphindb: {tagname} && docker run -itd -p 8848:8848 --name dolphindb dolphindb/dolphindb: {tagname} sh. Please choose the specific image that you want to ... black suit and vestWebApr 11, 2024 · 在对上述两项业务改造升级的过程中，DolphinDB在存储、查询方面展现出的领先性能和强大的计算和流数据实时分析能力，让该头部外资银行看到了更多的可能性 … fowsniffcorpWebVue RouterVue Router 是 Vue.js 官方的路由管理器。. 它和 Vue.js 的核心深度集成，让构建单页面应用变得易如反掌。. 包含的功能有：嵌套的路由/视图表 模块化的、基于组件的路由配置 路由参数、查询、通配符 基于 Vue.js 过渡系统的视图过渡效果 细粒度的导航控制 ... fowstudio.comWebOct 29, 2024 · There’s a popular misconception that “1” in COUNT(1) means “count the values in the first column and return the number of rows.” From that misconception follows a second: that COUNT(1) is faster because it will count only the first column, while COUNT(*) will use the whole table to get to the same result.. This is not true. The number in the … fowshopWebAnnual precipitation amounts range from 30 - 40 inches in the east, while drier conditions are common in the west. In Kansas, you can enjoy four distinct seasons, each with … black suit and white shirthttp://duoduokou.com/sql/40863855555549419430.html black suit anime boy