A distributed database management system (DDBMS) manages databases that are stored on multiple computers, often in different locations. A parallel database management system (parallel DBMS) uses multiple processors to perform operations on a single database, improving performance by dividing tasks among these processors. In essence, DDBMS focuses on data distribution and replication across different sites, while parallel DBMS focuses on high-speed data processing using multiple processors.
Actually ACID is the combination of the 1# letters of the properties that DDBMS (Distributed - DBMS) possesses. A - Atomicity C - Consistency I - Isolation D - Durability This four property defines the architecture of DDBMS.
DataBase Management System (DBMS)is a software package# it allows data to be effectively stored, retrieved and manipulatedand # the data stored in a DBMS packege can be accessed by multiple users and by multiple application programs like (SQL Server, Oracle, Ms-Access) .Types of DBMS# Hierarachical DBMS (HDBMS)# Network DBMS (NDBMS)# Relational DBMS (RDBMS)# Object Oriented DataBase(OODB)# Distributed DBMS (DDBMS)
A homogeneous Distributed Database Management System (DDBMS) uses a single DBMS product to manage the databases spread across multiple locations in a network. The data model, query language, and transaction management are consistent across all nodes, streamlining operations and ensuring data consistency. This approach simplifies administration and maintenance as all nodes are governed by the same DBMS software.
combines everything into a single system including, DBMS software,hardware, application programs and user interface
functions of DBA in DBMS
Except DDBM to have the funcationality of DBMS. It also has the folliwing funcationalities: 1. Extended Communication Services. 2. Extended Data Dictionary. 3. Distributed Query Processing. 4. Extended Concurrency Control. 5. Extended Recovery Services.
1) complexity is more compared to centralized DBMS 2) It is much more expensive to setup and maintain a DDBMS. More hardware is required the network maintenance is increased the communication costs increase and there will be additional labour costs. 3) It is much more difficult to maintain a secure network system across multiple locations. The network needs to be made secure and access to replicated data needs to be maintained across multiple sites. 4)Integrity control is more difficult 5)Lack of standard 6)lack of experience 7)more complex database design
data base administrator is the person who control the data in the organisation its main function to control the information of the particular enterprise1.3 Functions of a DBMSThe functions performed by a typical DBMS are the following:· Data DefinitionThe DBMS provides functions to define the structure of the data in theapplication. These include defining and modifying the record structure, thetype and size of fields and the various constraints/conditions to be satisfied bythe data in each field.· Data ManipulationOnce the data structure is defined, data needs to be inserted, modified ordeleted. The functions which perform these operations are also part of theDBMS. These function can handle planned and unplanned data manipulationneeds. Planned queries are those which form part of the application.Unplanned queries are ad-hoc queries which are performed on a need basis.· Data Security & IntegrityThe DBMS contains functions which handle the security and integrity of datain the application. These can be easily invoked by the application and hencethe application programmer need not code these functions in his/herprograms.· Data Recovery & ConcurrencyRecovery of data after a system failure and concurrent access of records bymultiple users are also handled by the DBMS.· Data Dictionary MaintenanceMaintaining the Data Dictionary which contains the data definition of theapplication is also one of the functions of a DBMS.· PerformanceOptimizing the performance of the queries is one of the important functions ofa DBMS. Hence the DBMS has a set of programs forming the Query Optimizerwhich evaluates the different implementations of a query and chooses thebest among them.Thus the DBMS provides an environment that is both convenient and efficient to usewhen there is a large volume of data and many transactions to be processed.
Organizations may be distributed across a wide geographic area. It is natural for databases to be set up to reflect this. Local areas will keep local information and this allows local users to quickly access the local database. A headquarters may also wish to make global inquiries to local data at the local regions. This allows users at one site to access data stored at other sites. Data is placed close to the users who normally access this data, it gives them local control and allows them to set up and establish local policies regarding the data use. A global administrator is responsible for the entire system and should help at a local level to develop and manage the dbms. Data in a centralized DB is inaccessible if there is a problem with the DB. However i a distributed site the local data is only inaccessible and if replication is i force then all data may be available at another site. Since data is kept local then local access is much quicker than access to a centralized DB. A DDBMS is much more complex than a centralized DB. If there are conflicts in hardware and software in use then this may cause performance issues and the sited advantages may become disadvantages. It is much more expensive to setup and maintain a DDBMS. More hardware is required the network maintenance is increased the communication costs increase and there will be additional labour costs. It is much more difficult to maintain a secure network system across multiple locations. The network needs to be made secure and access to replicated data needs to be maintained across multiple sites.
NA_ what are highlights of advanced DBMS what are highlights of advanced DBMS what are highlights of advanced DBMS
It depends on what database are you using. There are some ways in PHP but the most common of them are PHP native database driver and PDO. PHP native database driver is a collection of functions to communicate with a particular DBMS, they usually have the DBMS name prefixed in the function name. For example, driver functions for MySQL have mysql_* prefix.