db2 relational database

relational database query processing stepsFour steps to query processing: Query analysis Query check Query optimization Query execution 1. Query analysisLexical and grammatical analysis is the main analysis.First, the entire SQL statement is scanned, according to the data in the database data marker, identify the SQL keyword, relationshi

In the process of DB2 development, one of the most important tasks throughout the development process is the maintenance of the database, which is necessary to maintain a large information system; Leave a simple maintenance manual for a rainy year; The following parts of the maintenance order are collected to treat our maintenance engineers and project managers. * update:2006-06-14 *

Label:Query Manager Query management is an indicator of whether a database is strong or not. With query management, you can convert a bad query statement into a fast-executing code that returns results to the client manager after the code executes. The whole process is divided into multiple steps: The query is parsed first and its validity is checked; Rewrite the query and delete unnecessary operations, and do some pre-optimization;

Tags: Technology images semantic Data Technology sharing Chapter basic concept relationship model aboutChapter II Relational databasesRelational database is the most important and most widely used database system.This chapter focuses on the basic concepts of relational models, namely, the data structure of

Label:The disadvantages of relational databases: with the rise of Internet web2.0 Web site, the traditional relational database in dealing with web2.0 website, especially the super-large-scale and high-concurrency SNS type web2.0 pure dynamic website has appeared to be inadequate, exposing a lot of difficult problems to overcome , For example: 1. High performance

NoSQL systems generally advertise a feature, that is, good performance. Why? After so many years of development in relational databases, various optimizations have been done very deeply. NoSQL systems generally use relational database technology. What factors have bound the performance of relational databases? We can l

Sesame HTTP: Non-relational database storage, Sesame database storage NoSQL stands for Not Only SQL, meaning Not Only SQL, but also non-relational databases. NoSQL is based on key-value pairs and does not need to be parsed at the SQL layer. There is no coupling between data and the performance is very high. Non-

requests to multiple data sources that are distributed across different locations. Federated database systems can connect local tables to remote data sources, just as data is local, and can improve data source processing by distributing requests to the data source, and you can supplement the SQL limit of the data source by processing partial distribution requests at the Federated server. Federated databases have two different features from other app