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Summary - Coggle Diagram
Summary
Parallel database
Widely marketed today
Need for transaction requirements
The set-oriented nature of database queries is suitable for parallelization
Machines more common and affordable
Individual processors have also become parallel machines with multicore architectures.
Interoperation Parallelism
Pipelined Parallelism
Source of computation economy for database query processing
Allows the output tuples of one operation to be consumed by a second operation before the first operation has produced the entire set of tuples in its output
Pipelined execution
Allows for a sequence of operations to be carried out without intermediate results being written to disk
Independent Parallelism
Operations in a query expression that do not depend on one another can be executed in parallel
Less useful in highly parallel systems
Homogeneous and Heterogeneous Databases
Homogeneous distributed database
You have the same database management software that cooperate in the processing of applications and relinquish their autonomy
Heterogeneous distributed database
May have schema and database management software which makes transaction and query processing difficult
Directory Systems
Directory Access Protocols
Can store different types of information
Directory access protocols provide a way to access data in a directory.
Provide a simple way of naming objects in a hierarchical fashion
LAAP: Lightweight Directory Access Protocol
LDAP Data Model
Stores entries in directories that are similar to objects
Each entry must have a unique distinguished name (DN)
The attributes of an entry are key-value pairs
Allows entries to have multiple values for an attribute.
Data Manipulation
Not have a data-definition language or a data-manipulation language
LDAP defines a network protocol for data definition and manipulation
Can be used for storing and exchanging information.
Is composed of one or more servers that serve multiple clients
Clients use an API defined by the directory system to communicate with the servers
The X.500 directory access protocol is complex
LDAP provides similar features to X.500 with less complexity