|
A partition is a division of a logical database or its constituting elements into distinct independent parts. A database is an organized collection of data. ...
Database partitioning is normally done for manageability, performance or availability reasons. This page is a candidate to be moved to Wiktionary. ...
A street musician with accordion in Bremen A performance comprises an event in which generally one group of people (the performer or performers) behave in a particular way for the benefit of another group of people (the viewer or viewers, or audience). ...
In telecommunications and reliability theory, the term availability has the following meanings: 1. ...
The partitioning can be done by either building separate smaller databases (each with its own tables, indexes, and transaction logs), or by splitting selected elements, for example just one table. In a relational database (RDB), a table is a set of data elements (cells) that is organized, defined and stored as horizontal rows (records) and vertical columns (fields) where each item can be uniquely identified by a label or key or by it’s position in relation to other items. ...
This article is in need of attention from an expert on the subject. ...
A transaction is an agreement, communication, or movement carried out between separate entities or objects. ...
Partitioning criteria
Current high end relational database management systems provide for different criteria to split the database. They take a partitioning key and assign a partition based on certain criteria. Common criteria are: A relational database management system (RDBMS) is a database management system (DBMS) that is based on the relational model as introduced by Edgar F. Codd. ...
- Range partitioning
- Selects a partion by determining if the partitioning key is inside a certain range. An example could be a partition for all rows where the column
zipcode has a value between 70000 and 79999. - List partitioning
- A partition is assigned a list of values. If the partitioning key has one of these values, the partition is chosen. For example all rows where the column
Country is either Iceland, Norway, Sweden, Finland or Denmark could build a partition for the Nordic countries. - Hash partitioning
- The value of a hash function determines membership in a partition. Assuming there are four partitions, the hash function could return a value between 0 and 3.
Composite partitioning allows for certain combinations of the above partitioning schemes, by for example first applying a range partitioning and then a hash partitioning. In the context of a relational database, a row represents a single, implicitly structured data item in a table. ...
In the context of a relational database, a column of a table is a set of data values of a particular simple type, one for each row of the table. ...
The Nordic countries (Greenland not shown) The Nordic countries is a term used collectively for five countries in Northern Europe. ...
A hash function or hash algorithm is a function for summarizing or probabilistically identifying data. ...
See also The following tables compare general and technical information for a number of relational database management systems. ...
External links |
Feeds |
Contact