Comparison of RDBMS, OODBMS and ORDBMS
... The essential distinction between these two In such a situation each class corresponds to types of data modeling is represented by the a relation, the attributes of a particular class encapsulation in the object of both is state will become attributes corresponding to a reand behavior with the objec ...
... The essential distinction between these two In such a situation each class corresponds to types of data modeling is represented by the a relation, the attributes of a particular class encapsulation in the object of both is state will become attributes corresponding to a reand behavior with the objec ...
Database Security - Department of Computer Science and
... to lose that privilege; referred to as cascading of the revoke. We can prevent cascading by specifying restrict: revoke select on branch from U1, U2, U3 restrict With restrict, the revoke command fails if cascading revokes are required. ...
... to lose that privilege; referred to as cascading of the revoke. We can prevent cascading by specifying restrict: revoke select on branch from U1, U2, U3 restrict With restrict, the revoke command fails if cascading revokes are required. ...
Job Description – Centre Support Assistant
... 8:30 – Catch up with some of the team who are already in (we have flexi time, so start and end times are varied) and then head to the tea point to make a drink. 8.45 – I begin my day of database administration by checking for alerts, I have monitoring tools and scripts that will alert me when things ...
... 8:30 – Catch up with some of the team who are already in (we have flexi time, so start and end times are varied) and then head to the tea point to make a drink. 8.45 – I begin my day of database administration by checking for alerts, I have monitoring tools and scripts that will alert me when things ...
Logical Data Modelling
... Database Theory = Relational Model • First proposed by Dr. E. F. Codd in June 1970. – Codd E F, (1970), A Relational Model of Data for Large Shared Data Banks, Communications of the ACM, Vol. 13, No. 6, Pgs 377 – 387. ...
... Database Theory = Relational Model • First proposed by Dr. E. F. Codd in June 1970. – Codd E F, (1970), A Relational Model of Data for Large Shared Data Banks, Communications of the ACM, Vol. 13, No. 6, Pgs 377 – 387. ...
Spatial Database Systems
... A spatial database is a database that is enhanced to store and access spatial data or data that defines a geometric space. Data on spatial databases are stored as coordinates, points, lines, polygons and topology. Spatial RDBMS allows to use SQL data types, such as int and varchar, as well as spatia ...
... A spatial database is a database that is enhanced to store and access spatial data or data that defines a geometric space. Data on spatial databases are stored as coordinates, points, lines, polygons and topology. Spatial RDBMS allows to use SQL data types, such as int and varchar, as well as spatia ...
Limitations of the Relational Model
... relational model in general, and to an objectoriented model in particular? 1. There are some forms of data and knowledge which the relational model cannot accommodate easily and adequately. 2. Object-oriented programming languages are emerging as the dominant form within development environments for ...
... relational model in general, and to an objectoriented model in particular? 1. There are some forms of data and knowledge which the relational model cannot accommodate easily and adequately. 2. Object-oriented programming languages are emerging as the dominant form within development environments for ...
Components of a Database System
... 1. SQL(Structured Query Language): Data access language (CH 9) 2. QBE(Query By Example): (Figure 2-8) 3. QBF(Query By Form): user types query constraints on a data entry form and press search button ...
... 1. SQL(Structured Query Language): Data access language (CH 9) 2. QBE(Query By Example): (Figure 2-8) 3. QBF(Query By Form): user types query constraints on a data entry form and press search button ...
Storing Data: Disks and Files
... requested at the same time? What if the same page is requested multiply? ...
... requested at the same time? What if the same page is requested multiply? ...
Database Systems - Seneca - School of Information
... Database design for E-Commerce uses the same concepts as if designing for a DDBMS or client/server with a few exceptions….. ...
... Database design for E-Commerce uses the same concepts as if designing for a DDBMS or client/server with a few exceptions….. ...
Chapter 10
... • A database is defined in terms of Schema Objects and Tablespaces. – Schema Objects contain definitions of tables, views, sequences, stored procedures indexes, clusters and database links. – Tablespaces, segments and extents are the terms used to describe the physical storage. Chapter 10 ...
... • A database is defined in terms of Schema Objects and Tablespaces. – Schema Objects contain definitions of tables, views, sequences, stored procedures indexes, clusters and database links. – Tablespaces, segments and extents are the terms used to describe the physical storage. Chapter 10 ...
Slides
... This is achieved via maintaining a log (i.e., history) of all writes to the database Before a change is made to the database, the corresponding log entry is forced to a safe location (this protocol is called Write-Ahead Log or WAL) After a crash, the effects of partially executed transactions ...
... This is achieved via maintaining a log (i.e., history) of all writes to the database Before a change is made to the database, the corresponding log entry is forced to a safe location (this protocol is called Write-Ahead Log or WAL) After a crash, the effects of partially executed transactions ...
11g General New Features
... • Freeing key personal for higher value tasks! • Provides the least expensive, most scalable, secure and highly available rapid application development environment! ...
... • Freeing key personal for higher value tasks! • Provides the least expensive, most scalable, secure and highly available rapid application development environment! ...
Databases - Relational Data Model
... Many data models have been proposed: Hierarchical Model Network Model Relational Model Object-Relational Model Object-Oriented Model The hierarchical and network models are older models that provide only limited functionality, while the object-oriented model is not yet practical. ...
... Many data models have been proposed: Hierarchical Model Network Model Relational Model Object-Relational Model Object-Oriented Model The hierarchical and network models are older models that provide only limited functionality, while the object-oriented model is not yet practical. ...
VLDB Workshop on Datamanagement in Grids
... • For specialised data models, WS-DAI provides a starting point for designs. • Advantages: – Many fiddly design decisions are made for you. – Examples exist for use as templates. – Consistent with other realisations: • Conforms to expectations. • Quicker learning. • Able to share implementation expe ...
... • For specialised data models, WS-DAI provides a starting point for designs. • Advantages: – Many fiddly design decisions are made for you. – Examples exist for use as templates. – Consistent with other realisations: • Conforms to expectations. • Quicker learning. • Able to share implementation expe ...
database transformation
... The first operating systems were developed for mainframes. These operating systems were extreme proprietary and could only work on a specific hardware. Both hardware and OS were very expensive and only few companies could afford them. In the mid-1970s, with the introduction of microcomputers new ope ...
... The first operating systems were developed for mainframes. These operating systems were extreme proprietary and could only work on a specific hardware. Both hardware and OS were very expensive and only few companies could afford them. In the mid-1970s, with the introduction of microcomputers new ope ...
PDF
... unique identifier - and is efficient as distributed if all you wish to do is locate a single structure using the PDB code found in the file name. The computer operating system can perform this query with a ...
... unique identifier - and is efficient as distributed if all you wish to do is locate a single structure using the PDB code found in the file name. The computer operating system can perform this query with a ...
Centralized Systems
... Database System Architectures Centralized Systems Client--Server Systems Parallel Systems Distributed Systems Centralized Systems Run on a single computer system and do not interact with other ...
... Database System Architectures Centralized Systems Client--Server Systems Parallel Systems Distributed Systems Centralized Systems Run on a single computer system and do not interact with other ...
Transactions
... checkpoint) to identify all Xacts that were active, and all dirty pages in the buffer pool at the time of the crash. Redo: Redoes all updates to dirty pages in the buffer pool, as needed, to ensure that all logged updates are in fact carried out and written to disk. Undo: The writes of all Xacts tha ...
... checkpoint) to identify all Xacts that were active, and all dirty pages in the buffer pool at the time of the crash. Redo: Redoes all updates to dirty pages in the buffer pool, as needed, to ensure that all logged updates are in fact carried out and written to disk. Undo: The writes of all Xacts tha ...
Database Modelling with ERwin
... • “Always” use Integer and Identity(1,1) for Primary Keys. Use UNIQUE constraint for other columns that needs to be unique, e.g. “RoomNumber” • Specify Required Columns (NOT NULL) – i.e., which columns that need to have data or not ...
... • “Always” use Integer and Identity(1,1) for Primary Keys. Use UNIQUE constraint for other columns that needs to be unique, e.g. “RoomNumber” • Specify Required Columns (NOT NULL) – i.e., which columns that need to have data or not ...
