The Compression pages display summaries of the compressed storage space at the database level and the tablespace level. On the database level, the Compression Summary for Database page shows the total database size total size of all the objects, both compressed and uncompressedthe total size of compressed objects in the database, the total size of uncompressed objects in the database and the ratio of the total size of compressed objects to the total database size.
Source of the data Process used to create the data For example, a digital image may include metadata that describes how large the picture is, the color depth, the image resolution, when the image was created, the shutter speed, and other data. Metadata within web pages can also contain descriptions of page content, as well as key words linked to the content.
But if given the context that this database is a log of a book collection, those digit numbers may now be identified as ISBNs - information that refers to the book, but is not itself the information within the book.
The term "metadata" was coined in by Philip Bagley, in his book "Extension of Programming Language Concepts" where it is clear that he uses the term in the ISO "traditional" sense, which is "structural metadata" i. In these fields the word metadata is defined as "data about data". Types[ edit ] While the metadata application is manifold, covering a large variety of fields, there are specialized and well-accepted models to specify types of metadata.
Guide metadata helps humans find specific items and are usually expressed as a set of keywords in a natural language.
According to Ralph Kimball metadata can be divided into 2 similar categories: Technical metadata corresponds to internal metadata, and business metadata corresponds to external metadata. Kimball adds a third category, process metadata.
On the other hand, NISO distinguishes among three types of metadata: Structural metadata describes how the components of an object are organized.
An example of structural metadata would be how pages are ordered to form chapters of a book. Finally, administrative metadata gives information to help manage the source. Administrative metadata refers to the technical information, including file type, or when and how the file was created.
Two sub-types of administrative metadata are rights management metadata and preservation metadata. Rights management metadata explains intellectual property rights, while preservation metadata contains information to preserve and save a resource.
An additional type of metadata beginning to be more developed is accessibility metadata. Accessibility metadata is not a new concept to libraries; however, advances in universal design have raised its profile. Those types of information are accessibility metadata. While the efforts to describe and standardize the varied accessibility needs of information seekers are beginning to become more robust their adoption into established metadata schemas has not been as developed.
Tools such as controlled vocabulariestaxonomiesthesauridata dictionariesand metadata registries can be used to apply further standardization to the metadata. Structural metadata commonality is also of paramount importance in data model development and in database design.
Syntax[ edit ] Metadata metacontent syntax refers to the rules created to structure the fields or elements of metadata metacontent.
There is always an implied statement in any "classification" of some object. To classify an object as, for example, Dewey class number Topology i. This is a subject-predicate-object triple, or more importantly, a class-attribute-value triple. The first two elements of the triple class, attribute are pieces of some structural metadata having a defined semantic.
The third element is a value, preferably from some controlled vocabulary, some reference master data. The combination of the metadata and master data elements results in a statement which is a metacontent statement i.
All of these elements can be thought of as "vocabulary". Both metadata and master data are vocabularies which can be assembled into metacontent statements. There are many sources of these vocabularies, both meta and master data: Using controlled vocabularies for the components of metacontent statements, whether for indexing or finding, is endorsed by ISO The process indexes pages then matches text strings using its complex algorithm; there is no intelligence or "inferencing" occurring, just the illusion thereof.
Hierarchical, linear and planar schemata[ edit ] Metadata schemata can be hierarchical in nature where relationships exist between metadata elements and elements are nested so that parent-child relationships exist between the elements. An example of a hierarchical metadata schema is the IEEE LOM schema, in which metadata elements may belong to a parent metadata element.
Metadata schemata can also be one-dimensional, or linear, where each element is completely discrete from other elements and classified according to one dimension only. An example of a linear metadata schema is the Dublin Core schema, which is one dimensional. Metadata schemata are often two dimensional, or planar, where each element is completely discrete from other elements but classified according to two orthogonal dimensions.ESRI Shapefile is a file format for storing geospatial vector rutadeltambor.com has been around since the early s and is still the most commonly used vector data exchange format.
While Shapefiles have enabled many successful activities over the years, they also have a number of limitations that complicate software development and reduce efficiency. Introduction. This paper gives a high-level overview of how to use XML with databases.
It describes how the differences between data-centric and document-centric documents affect their usage with databases, how XML is commonly used with relational databases, and what native XML databases are and when to use them.
Comparison of different SQL implementations. The goal of this page — which is a work in progress — is to gather information relevant for people who are porting SQL from one product to another and/or are interested in possibilities and limits of 'cross-product' SQL..
The following tables compare how different DBMS products handle various SQL (and related) features. Chapter 1 Introduction The purpose of this manual is to introduce public agencies to the methods available for controlling public records entrusted to their care, with emphasis on the tools needed to solve record- keeping problems, increase efficiency, improve services and save money.
NEW JERSEY RECORDS MANUAL: New Jersey Department of the Treasury Division of Revenue and Enterprise Services January, Comparison of different SQL implementations. The goal of this page — which is a work in progress — is to gather information relevant for people who are porting SQL from one product to another and/or are interested in possibilities and limits of 'cross-product' SQL..
The following tables compare how different DBMS products handle various SQL (and .