DELPHI数据集组件Query，是delphi的数据库操作比用口按件，使用简洁。

ctp海风mongodb入库.直接连接CTP接口持久化存储数据

Upcall routine, designed to work as a key type and working through for Linux v2.13.6.

SharepointQueryTool for Sharepoint 2013 ,Client Query Search Result

Lec09 Query Processing 03 树索引1

概述 QueryBuilder 使您无需输入单个按键即可构建和运行复杂的数据库查询。 它提供与 Analyzer 相同类型的分析，但它使用一种非常不同的方法。 服务器维护一个数据库，它用于配置信息以及来自其他数据库的表或视图的快照。 配置信息描述了已为系统定义的数据库和表。 基于浏览器的客户端应用程序具有熟悉的拖放式查询构建器，支持任意数量的并发数据库连接。 它包括以下功能： 创建到多个服务器数据库的连接（通过 JDBC） 将表添加到查询构建器面板 选择要显示的列 指定加入条件 指定过滤条件 运行查询 从表或视图导入快照 定义计算列 描述和显示表格 创建数据透视查询 通常，客户端使用拖放比喻来允许您与对象进行交互。 此外，双击通常执行最常见的操作，因此只需双击或拖放即可创建范围广泛的查询。 当然，复杂且高度定制的查询确实需要一些输入！ QueryBuilder 用户界面导览 创建

Query optimizer is at the heart of the database systems. Cost-based optimizer studied in this paper is adopted in almost all current database systems. A cost-based optimizer introduces a plan enumeration algorithm to find a (sub)plan, and then uses a cost model to obtain the cost of that plan, and selects the plan with the lowest cost. In the cost model, cardinality, the number of tuples through an operator, plays a crucial role. Due to the inaccuracy in cardinality estimation, errors in cost...

DB - Balancing Vectorized Query Execution with Bandwidth-Optimized Storage.pdf I had two supervisors at CWI. Martin Kersten always kept an eye on what this new student from Poland was doing, and teased me with hard problems and tricky questions when appropriate. Still, it was Peter Boncz who had to live with all my questions, ideas, problems and complaints almost every day. The discussions we had were one of the most thought-stimulating moments of my life, even when we disagreed on ...

This doc describes a new extensible query optimization framework that resolves many of the shortcomings of the EXODUS and Volcano optimizer generators. In addition to extensibility, dynamic programming, and memorization based on and extended from the EXODUS and Volcano prototypes, this new optimizer provides (i) manipulation of operator arguments using rules or functions, (ii) operators that are both logical and physical for predicates etc., (iii) schema-specific rules for materialized views,

F1 Query is a stand-alone, federated query processing platform that executes SQL queries against data stored in different filebased formats as well as different storage systems at Google (e.g., Bigtable, Spanner, Google Spreadsheets, etc.). F1 Query eliminates the need to maintain the traditional distinction between different types of data processing workloads by simultaneously supporting: (i) OLTP-style point queries that affect only a few records; (ii) low-latency OLAP querying of large ...