554:. They reserved blocks of disc data space for partitions and used the allocated blocks more economically, by dynamically assigning blocks of a partition to a file as needed. To achieve this, the file system had to keep track of which blocks were used or unused by data files in a catalog or file allocation table. Though this made better use of the disc data space, it resulted in fragmentation of files across the disc, and a concomitant performance overhead due additional seek time to read the data. Modern file systems reorganize fragmented files dynamically to optimize file access times. Further developments in file systems resulted in
690:, rely on massively parallel distributed data processing across many commodity computers on a high bandwidth network. In such systems, the data is distributed across multiple computers and therefore any particular computer in the system must be represented in the key of the data, either directly, or indirectly. This enables the differentiation between two identical sets of data, each being processed on a different computer at the same time.
49:
460:(or links or paths) from the start of the structure, in which data values are stored. Therefore, the data key consists of the key to the structure plus the offset (or links or paths) into the structure. When such a structure is repeated, storing variations of the data values and the data keys within the same repeating structure, the result can be considered to resemble a
482:, such that nodes are linked to each other in a cascade of parent-child relationships. Values and potentially more complex data-structures are linked to the nodes. Thus the nodal hierarchy provides the key for addressing the data structures associated with the nodes. This representation can be thought of as an
417:
or memory. This is as opposed to data storage, where the CPU must direct the transfer of data between the storage device (disk, tape...) and memory. RAM is an array of linear contiguous locations that a processor may read or write by providing an address for the read or write operation. The processor
397:
Keys in data provide the context for values. Regardless of the structure of data, there is always a key component present. Keys in data and data-structures are essential for giving meaning to data values. Without a key that is directly or indirectly associated with a value, or collection of values in
464:, in which each element of the repeating structure is considered to be a column and each repetition of the structure is considered as a row of the table. In such an organization of data, the data key is usually a value in one (or a composite of the values in several) of the columns.
550:. In those systems, the files could be filled up, running out of data space before all the data had been written to them. Thus much unused data space was reserved unproductively to ensure adequate free space for each file. Later file-systems introduced
508:. All the values for subsets of the key appear together. When passing sequentially through groups of the data with the same key, or a subset of the key changes, this is referred to in data processing circles as a break, or a
214:
Data relating to physical events or processes will have a temporal component. This temporal component may be implied. This is the case when a device such as a temperature logger receives data from a temperature
630:
It is only after instantiation that an object of a specified class exists. After an object's reference is cleared, the object also ceases to exist. The memory locations where the object's data was stored are
578:
to reduce the time taken to retrieve a subset of the original data. In order to do this, the key of the subset of data to be retrieved must be known before retrieval begins. The most popular indexes are the
223:. So the device records the date, time and temperature together. When the data logger communicates temperatures, it must also report the date and time as metadata for each temperature reading.
857:
398:
a structure, the values become meaningless and cease to be data. That is to say, there has to be a key component linked to a value component in order for it to be considered data.
226:
Fundamentally, computers follow a sequence of instructions they are given in the form of data. A set of instructions to perform a given task (or tasks) is called a
252:
stored at a specific location. Therefore, it is possible for computer programs to operate on other computer programs, by manipulating their programmatic data.
880:
587:
key indexing methods. Indexing is overhead for filing and retrieving data. There are other ways of organizing indexes, e.g. sorting the keys and using a
232:. A program is data in the form of coded instructions to control the operation of a computer or other machine. In the nominal case, the program, as
275:. However, executable files may also contain data used by the program which is built into the program. In particular, some executable files have a
853:
800:
538:
of a predetermined size. In this case, the seek location on the media, is the data key and the blocks are the data values. Early used
172:
or SQL databases, and can generally be represented as abstract key/value pairs. Data can be organized in many different types of
574:
are a way to copy out keys and location addresses from data structures in files, tables and data sets, then organize them using
632:
568:
Retrieving a small subset of data from a much larger set may imply inefficiently searching through the data sequentially.
762:
341:
stored in another file. In this example, the document would be considered data. If the word processor also features a
211:
helps translate data to information. Metadata is data about the data. Metadata may be implied, specified or given.
286:, for example, is a program. The input data to an interpreter is itself a program, just not one expressed in native
418:
may operate on any location in memory at any time in any order. In RAM the smallest element of data is the binary
884:
478:
view of repeating data structures is only one of many possibilities. Repeating data structures can be organised
924:
279:, which nominally contains constants and initial values for variables, both of which can be considered data.
17:
830:
611:
623:
619:
601:
122:
121:. Data sourced from an analog device, such as a temperature sensor, may be converted to digital using an
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of disc drives i.e. where a logical drive can be defined as partitions from a number of physical drives.
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142:
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457:
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249:
267:. Typically, programs are stored in special file types, different from those used for other data.
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245:
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elements consist of an address and a byte/word of data storage. Digital data are often stored in
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1035:
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at run time, the creation of references to in-memory data-structures of objects that have been
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114:
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35:
413:(RAM) holds data that the CPU has direct access to. A CPU may only manipulate data within its
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in the form of digital electrical or optical signals. Data pass in and out of computers via
1165:
673:
535:
410:
354:
345:, then the dictionary (word list) for the spell checker would also be considered data. The
338:
219:. When the temperature is received it is assumed that the data has a temporal reference of
118:
534:. These devices typically seek to a location on the magnetic media and then read or write
8:
1105:
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523:
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197:
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422:. The capabilities and limitations of accessing RAM are processor specific. In general
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319:
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Data can be represented in computers in multiple ways, as per the following examples:
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452:, abstract and logical keys codes can be stored in association with values to form a
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Quantities, characters, or symbols on which operations are performed by a computer
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512:. It particularly facilitates the aggregation of data values on subsets of a key.
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similarly involves programs manipulating other programs as data. Programs like
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representation. In modern (post-1960) computer systems, all data is digital.
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Modern scalable and high-performance data persistence technologies, such as
530:, persistent data storage was traditionally achieved by writing the data to
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program from one file, and then use the running program to open and edit a
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The total amount of digital data in 2007 was estimated to be 281 billion
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Various types of data which can be visualized through a computer device
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0). Each location can store usually 8 or 32 bits depending on the
290:. In many cases, the interpreted program will be a human-readable
48:
822:
349:
used by the spell checker to suggest corrections would be either
248:(CPU), are also data. At its most essential, a single datum is a
129:, characters, or symbols on which operations are performed by a
580:
216:
69:
741:
244:
manipulated by the program, but not actually executed by the
854:"Study: amount of digital info > global storage capacity"
604:
uses two basic concepts for understanding data and software:
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635:
and are reclassified as unused memory available for reuse.
615:, which is an example of a hierarchical data structure; and
448:
Data keys need not be a direct hardware address in memory.
256:
42:
657:
532:
external block devices like magnetic tape and disk drives
491:
419:
883:. International Data Corporation via EMC. Archived from
282:
The line between program and data can become blurry. An
902:
680:
468:
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data file-systems or disc operating systems reserved
117:. Data moving to or from a computer, in most cases,
184:. Data structures can store data of many different
149:, electronic, or mechanical recording media, and
1198:
393:Data keys and values, structures and persistence
797:The Oxford pocket dictionary of current english
878:
595:
918:
94:system of ones (1) and zeros (0), instead of
881:"The diverse and exploding digital universe"
652:for persistent data storage. Databases use
504:Data has some inherent features when it is
322:and such use other programs as their data.
271:contain programs; all other files are also
925:
911:
851:
76:is a single symbol of data. Data requires
498:
113:. Data within a computer, in most cases,
47:
41:For broader coverage of this topic, see
14:
1199:
90:is data that is represented using the
64:(treated as singular, plural, or as a
906:
803:from the original on 28 November 2011
516:
456:. Data structures have predetermined
372:as distinguished from human-readable
879:Gantz, John F.; et al. (2008).
833:from the original on 5 February 2018
681:Parallel distributed data processing
486:. Modern computer operating system
469:Organised recurring data structures
353:data or text in some interpretable
24:
860:from the original on 13 March 2008
203:
25:
1218:
236:by the computer, will consist of
68:) is any sequence of one or more
638:
609:The taxonomic rank-structure of
676:completeness, when saving data.
562:
872:
845:
815:
785:
755:
664:systems, communicating over a
294:, which is manipulated with a
13:
1:
748:
546:blocks on the disc drive for
101:Data exists in three states:
852:Paul, Ryan (12 March 2008).
7:
694:
602:Object-oriented programming
596:Abstraction and indirection
426:is arranged as an array of
259:in a file, they have to be
123:analog-to-digital converter
10:
1223:
490:are a common example; and
40:
29:
940:
672:logging system to ensure
658:structured query language
522:Until the advent of bulk
329:might first instruct the
932:
737:State (computer science)
576:inverted tree structures
430:beginning at address 0 (
589:binary search algorithm
442:
368:) are sometimes called
360:In an alternate usage,
246:central processing unit
499:Sorted or ordered data
404:
115:moves as parallel data
53:
36:Datum (disambiguation)
648:introduced a further
436:computer architecture
51:
32:Data (disambiguation)
1106:Protection (privacy)
829:. 24 December 2015.
827:OpenBSD manual pages
650:layer of abstraction
411:Random access memory
355:programming language
176:, including arrays,
166:relational databases
125:. Data representing
119:moves as serial data
30:For other uses, see
524:non-volatile memory
415:processor registers
793:"Computer program"
517:Peripheral storage
240:. The elements of
155:peripheral devices
54:
1194:
1193:
1186:Wrangling/munging
1036:Format management
662:client and server
660:protocol between
16:(Redirected from
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927:
920:
913:
904:
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897:
896:
894:
892:
887:on 11 March 2008
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856:. Ars Technics.
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813:
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769:. Archived from
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670:two phase commit
666:computer network
583:and the dynamic
331:operating system
316:program updaters
288:machine language
269:Executable files
58:computer science
21:
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1166:Synchronization
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712:Data dictionary
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506:sorted on a key
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471:
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364:(which are not
325:For example, a
300:Metaprogramming
206:
204:Characteristics
198:data structures
196:and even other
174:data structures
162:computer memory
107:data in transit
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1091:Pre-processing
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732:Database index
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644:The advent of
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556:virtualization
536:blocks of data
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480:hierarchically
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454:data structure
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366:human-readable
335:word processor
320:virus scanners
255:To store data
205:
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78:interpretation
26:
9:
6:
4:
3:
2:
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1208:
1207:Computer data
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773:on 2019-06-23
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717:Data modeling
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674:transactional
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639:Database data
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624:class library
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510:control break
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343:spell checker
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18:Computer data
1096:Preservation
1086:Philanthropy
950:Augmentation
933:
889:. Retrieved
885:the original
874:
862:. Retrieved
847:
835:. Retrieved
826:
817:
805:. Retrieved
796:
787:
775:. Retrieved
771:the original
766:
757:
629:
620:instantiated
610:
569:
563:Indexed data
539:
488:file systems
400:
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380:
373:
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362:binary files
359:
351:machine code
324:
281:
277:data segment
254:
238:machine code
227:
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188:, including
159:
103:data at rest
100:
87:Digital data
85:
73:
61:
55:
1156:Stewardship
1046:Integration
995:Degradation
980:Compression
960:Archaeology
945:Acquisition
722:Data stream
494:is another.
432:hexadecimal
424:main memory
296:text editor
284:interpreter
265:file format
151:transmitted
111:data in use
82:information
1176:Validation
1111:Publishing
1101:Processing
1071:Management
985:Corruption
975:Collection
837:4 February
807:11 October
777:14 January
749:References
668:, using a
552:partitions
548:data files
544:contiguous
347:algorithms
333:to load a
273:data files
261:serialized
127:quantities
80:to become
1181:Warehouse
1146:Scrubbing
1126:Retention
1121:Reduction
1076:Migration
1051:Integrity
1019:Transform
970:Cleansing
823:"file(1)"
646:databases
428:locations
383:gigabytes
312:debuggers
304:compilers
298:program.
292:text file
160:Physical
66:mass noun
1201:Category
1151:Security
1141:Scraping
1116:Recovery
990:Curation
955:Analysis
891:12 March
864:13 March
858:Archived
831:Archived
801:Archived
727:Data set
702:Big data
695:See also
656:, and a
654:metadata
540:raw disk
450:Indirect
387:exabytes
339:document
234:executed
209:Metadata
143:magnetic
139:recorded
131:computer
1161:Storage
1136:Science
1131:Quality
1061:Lineage
1056:Library
1031:Farming
1014:Extract
1000:Editing
633:garbage
622:from a
612:classes
571:Indexes
476:tabular
458:offsets
308:linkers
242:storage
229:program
194:strings
190:numbers
182:objects
168:, like
147:optical
70:symbols
1081:Mining
1041:Fusion
767:Lexico
763:"Data"
581:B-tree
217:sensor
180:, and
178:graphs
170:tables
135:stored
96:analog
742:Tuple
528:flash
526:like
462:table
385:(281
263:in a
257:bytes
250:value
186:types
74:datum
1171:Type
1066:Loss
1024:Load
934:Data
893:2008
866:2008
839:2018
809:2012
779:2022
707:Data
585:hash
474:The
443:Keys
375:text
370:data
327:user
137:and
133:are
109:and
62:data
43:Data
34:and
1009:ELT
1005:ETL
965:Big
492:XML
420:bit
405:RAM
389:).
378:.
221:now
141:on
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