nosql database schema design

Paradigm (1NF) Definition: The attribute of each relation r of the fruit relational mode R is an irreducible data item, then it is called R as the mode of the first normal form. Simply put, each attribute is an atomic term, indivisible. 1NF is the minimum condition that the relational pattern should have, if the database design cannot satisfy the first normal form, it is not called the relational

One, the distinction of the concept Some people confuse object-oriented database design (i.e. database schema) with object-oriented database management system (OODBMS) theory. In fact, the former is a database user-defined

the mapping information:Tag table:The code is as follows:ID of the TagID # tag tagTagName #tag内容Num #当前Tag的引用个数Tagmap tableThe code is as follows:TagIDAidArticle tableThe code is as follows:ID #文章IDTitle #文章标题Tags #tags列表, multiple to, split...In this form, the tag table and the Tagmap table are updated each time the content is published and the content is modified.When querying, you need to find the article ID of the response from the Tagmap table, and then use the article ID to query the spec

. main attribute:　　　　 The candidate main attribute is called the main attribute (primary attribute). 　　　　Non-primary attribute/non-code attribute : A property that is not contained in any candidate code, called a non-primary attribute . 　　　　full code : All the attributes in the relational schema form the candidate code for this relational pattern, which is called a full-size attribute group . 　　　　 "Precautions" Code/Candidate code/main code/full c

The first is nonsense: Previous Article: How should we design a database? (1) How should we design a database? (2) In "how to design a database (ii)", Jack London Chen raised some questions, which are roughly as follows: "Man/wom

I would like to discuss with you how to design a database. More specifically, it is not about the principles of database design, but about the design of a database in Engineering. I am a beginner. I have never participated in stan

within the database partition, isolation and management, for the application only need to connect to the database, do not need to set up a corresponding data background for each application. 3. Storing Data structuresFor the requirements of multi-mode database, the storage data structure of distributed database also h

. Document Database design pattern 2 {"_id": "A", "Children": ["B", "C"]} {"_id": "B", "Children": ["D"]} {"_id": "C"} {"_id": "D"} Save all the child nodes of each node advantages : Simple structure, convenient to find sub-nodes: Finding The parent node can be troublesome E. Document database design Patterns 3 {"

must be an exact name that has a definite meaning in the schema. Better yet, the name should be enterprise-wide, industry-wide or globally prioritized. In the 2nd chapter, we will decide to put the data into the computer by selecting the appropriate domain. Domain idea to go back to Dr. Codd. Well, actually before this good doctor (good Doctor), because it comes from math. The data types in domain image programming, but involve more. The domain has a

In fact, I have been preparing the basic materials for another blog post, but I chatted with my friends and asked me what I was doing recently. I said I was working on the System Log Module, after talking with him, this blog came into being. All data can be expressed as follows: ID, table name, column name, and Value. For example, there is a data entry into the User table: IDGuid. Int is used here for convenience) Username Password Email 1 CrazyJinn 1

sort by the number of views, what do I do? Then there is the second design approach, which is the embodiment of NoSQL = not-only SQL. There are authors and articles two collection Author { _id:new obectid ("Blublublu"), Name: ' Portwatcher ', age : ' + ', email: ' [email protected] ' } Article { _id:new ObjectID ("Lalalala"), titl

Atitit. Physical storage structure principle and architecture design and practice of database tables 1. The storage model for Oracle and DB2 databases is shown in figure: 1 1.1.2. Storage of table data in blocks and ROWID information 3 2. The physical storage structure of the data table is natural sequence, with the Btree storage structure 3 2.1. The stored order of the records in the normal table is stor

services, It is also capable of providing read services specifically to one or more slave.Pros: The biggest benefit is that the primary master's write operation is not affected by the replication of the slave cluster, while the primary master does not have to be re-replication when it needs to switch.Disadvantage: This architecture also has a disadvantage, that is, the backup master may become a bottleneck, because if the subsequent slave cluster is larger, the standby master may become a bottl

stored with unsigned shaping (unsigned int)Avoid using the text blob enum typeTry to define the column as NOT NULLStoring time with a large datetime or timestamp typeFinancial-related amount class data must use the decimal type5 Database SQL Development specificationUsing precompiled statements for database operations is recommendedAvoid using double-percent query conditions like%w%Future extensions should

In "How to Design Database 2)", Jack London Chen raised some questions, which are roughly as follows: "Man/woman should be designed in the same table. Most user tables are designed as one table. Neither administrator nor user can be connected ." I think it's still because my example is too casual, because in the blog, Man and Woman have only four different attributes: HasCar \ HasHouse \ HasMoney, and IsBea

program | stored Procedure | design | data | Database This article explains how to use DBMS stored procedures. Describes the basic and advanced features of using stored procedures, such as returning resultset. This article assumes that you are already familiar with the DBMS and JDBC, and that you can read the code written in other languages without any hindrance (that is, not the Java language), but it does

should not grow indefinitely. If there are hundreds of document objects on the many side, do not embed them with a reference to the Objectid scheme, if there are thousands of document objects, then do not embed objectid arrays. Which scenarios to take depends on the size of the array. 4. Do not be afraid to apply layer-level joins: If the index is built correctly and the results are limited by the projection criteria (mentioned in chapter II), then the join at the application tier level will no

A relational database is designed to conform to certain rules. In particular, database design paradigm is briefly introduced 1NF (first normal form), 2NF (second normal form), 3NF (third normal form) and BCNF, another fourth normal form and fifth normal form are left to be introduced later. When you design a

Introduction of relational database design paradigm 1. The first normal form (1NF) has no duplicate columns The so-called first normal form (1NF) means that each column of a database table is an indivisible basic data item and cannot have multiple values in the same column, that is, an attribute in an entity cannot have more than one value or cannot have duplic

have multiple wards, a doctor only belong to a department, a department can have more than one doctor, a doctor can be responsible for the diagnosis and treatment of multiple patients, a patient's competent doctor only one. A patient can only stay in one ward, and a ward may accommodate multiple patients. Complete the following design: (1) the E-r Diagram (2) of the Computer Management system is designed to convert the E-r diagram into a relational