relational database diagram tool

Compare Items MongoDB mysql/oracleTable Collection list Two-dimensional tables tableA row of data in a table document a record recordingTable Keys key Fields fieldField value Values value valuePrimary foreign Key No PK,FKVery high flexibility and very poor degree of scalability1. The record of the tables in the relational database must be guaranteed to have the same field2.MongoDB each document key can be d

Tags: connect dir date overwrite char post arch src 11.2.0.1Due to the increasing volume of business data and the large amount of computing, the traditional number of silos has been unable to meet the computational requirements, so it is basically to put the data on the Hadoop platform to implement the logical computing, then it involves how to migrate Oracle Data Warehouse to the Hadoop platform. Here we have to mention a very useful tool--sqoop, whi

After creating a new database or attaching a database, if you want to add a relational table, the following error occurs:The database does not have a valid owner, so you cannot install the database relational

Database relationship diagram;The SQL serverssms GUI provides a very useful tool. It can display the relationship between tables and other objects in a graphical manner, and we can also add, modify, and other database objects in a graphical way. Before learning, let's take a look at what is the relationship between tab

MONGODB1, MongoDB optimization: A, statement optimization may find a long execution time statement through the profile. Db.getProfiling.Level () to get the profile level Db.system.profile.find () to view the profile record. B, after finding the statement, through the explain to parse the statement, you can see whether the index is used, what index? Db.collection.find ({xx:xx}). Explain (); C, through the results of explain to optimize the query statement. 2, MongoDB connection number: If the lar

After you create a new database or attach a database, you want to add a relational table, resulting in the following error: The database diagram support object cannot be installed because the database does not have a valid owner.

A general introduction to NoSQLHttp://www.apelearn.com/bbs/forum.php?mod=viewthreadtid=8660highlight=NoSQLmemcached Introduction1.3 memcached InstallationHttp://www.apelearn.com/bbs/thread-9285-1-1.htmlYum Install-y epel-releaseRpm-qa Epel-releaseYum install-y livevent memcached libmemcached/etc/init.d/memcached startNetstat-lnpPS aux |grep memcachedVi/etc/init.d/memcachedCat/etc/sysconfig/memcached-L Listener Server IPMemcached-tool 127.0.0.1:11211 S

redundancy, update exception, insert exception, delete exception)3NF: The non-primary attribute is directly dependent on the candidate key. (non-conforming data redundancy, update exception, insert exception, delete exception)BCNF: A non-primary property directly depends entirely on the candidate key, and the primary attribute is directly full function dependent on the key that does not contain it.The database design can be divided into three steps:1

There is no valid owner when creating a database relationship diagram. After restoring the database backed up by SQL2000 to sql2005, the "database relationship diagram" prompt: the database does not have a valid owner, so you cann

After you create a new database or attach a database, you want to add a relational table, resulting in the following error:The database diagram support object cannot be installed because the database does not have a valid owner. T

the customer needs to insert a database without flag. ID is the key. In the case of foreign key association, if the foreign key attribute is 0, the customer is new; otherwise, the customer already exists. In the case of independent association, if the customer Object ID is 0, the customer is new; otherwise, the customer already exists. 7.3.2 modify the persistent Relationship Diagram The problem arise

directionality, and there is a cardinality in each direction.ExampleThe link between "department" and "student" two entities is a one-to-many connection, in other words the link between "student" and "department" is a multi-pair connection. And a student must belong to a department, and can only belong to a department, can not belong to 0 departments, so from the "student" entity to "department" the base of the entity is "a", from the other side of the contact to consider, a department can have

One, review the foundation1. Weak entitiesSuch entities need to be dependent on one entity. If there is another entity that does not exist. It disappears as well. In contrast, the entity it relies on becomes a strong entity.2, SpecializationIn the process of database design, we will find. An entity can be divided into several sub-entities according to certain characteristics, which in fact is a process from general to special, which becomes specializa

Database E-R diagram correlation June 15, 2014: 39E-R data model adopted three main concepts: entity set, link set and attribute entity set: with the same type and the same nature (or attribute) object set attributes: simple attributes and compliant attributes; single-value Attributes and multi-value attributes; null attributes; derived attribute contact set: links are the associations between multiple enti

Database E-r diagram Correlation the years 6 Month the Day17:39The three main concepts used in the E-R data model are: entity sets, contact sets, and attributesEntity set: A collection of entities with the same type and the same nature (or attributes)Properties: Simple and conforming properties, single-valued and multivalued properties, null properties, derived propertiesContact Set: A contact is a correla

Database Design-Data Flow Diagram (DFD) and data flow dfd1. Data Flow Diagram definition data flow diagram (DFD) is a tool used in structural analysis. It graphically depicts the process of data flow and processing in the system, because it only reflects the logical function

Preface As has been heard, EA can not only draw various diagrams (UML, E-R diagram ...). , you can also turn diagrams into SQL scripts, software documents, and code for various languages. So, curious, I hope to take this opportunity to try this refactoring. A variety of documents are written almost, followed by modeling, building a database. So, I drew the E-R diagram