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is used here because a given character may be represented in different applications by more than one code, and different codes may use different numbers of bits (i.e., different byte sizes). In input-output transmission the grouping of bits may be completely arbitrary and have no relation to actual
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refers to the number of words transmitted to or from an input-output unit in response to a single input-output instruction. Block size is a structural property of an input-output unit; it may have been fixed by the design or left to be varied by the program.
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for the hardware responsible for storing and retrieving specified blocks of data, though the block size in file systems may be a multiple of the physical block size. This leads to space inefficiency due to
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denotes a group of bits used to encode a character, or the number of bits transmitted in parallel to and from input-output units. A term other than
263:, since file lengths are often not integer multiples of block size, and thus the last block of a file may remain partially empty. This will create
317:. DBMSes often use their own block I/O for improved performance and recoverability as compared to layering the DBMS on top of a file system.
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220:, blocking reduces the amount of external storage required for the data. Blocking is almost universally employed when storing data to
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consists of the number of data bits transmitted in parallel from or to memory in one memory cycle.
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This article is about the computer input/output technique. For the process scheduling concept, see
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Terms used here to describe the structure imposed by the machine design, in addition to
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is the process of extracting data from blocks. Blocked data is normally stored in a
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is thus defined as a structural property of the memory. (The term
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469:"Available hard drive space, block sizes, and size terminology"
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may be devices internal to a server, directly attached via
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Block storage is normally abstracted by a file system or
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Sequence of bits or bytes of a maximum predetermined size
364:/ The Maple Press Company, York, PA., pp. 39–40,
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was coined for this purpose by the designers of the
196:. The process of putting data into blocks is called
78:. Unsourced material may be challenged and removed.
278:, attempt to solve this through techniques called
414:, but respelled to avoid accidental mutation to
216:. For some devices, such as magnetic tape and
8:
358:Planning a Computer System – Project Stretch
180:, usually containing some whole number of
138:Learn how and when to remove this message
326:
408:characters. (The term is coined from
7:
520:"Bruning Questions: ZFS Record Size"
305:, or distant devices accessed via a
280:block suballocation and tail merging
76:adding citations to reliable sources
267:. Some newer file systems, such as
212:and speeds up the handling of the
25:
543:Bourbonnais, Roch (2006-06-07).
52:
379:from the original on 2017-04-03
339:Brooks, Jr., Frederick Phillips
309:(SAN) using a protocol such as
63:needs additional citations for
362:McGraw-Hill Book Company, Inc.
286:support variable block sizes.
282:. Other file systems such as
1:
231:, and rotating media such as
184:, having a maximum length; a
518:Balik, Rachel (2013-03-29).
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291:database management system
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87:"Block" data storage
37:Not to be confused with
545:"Tuning ZFS recordsize"
347:"4: Natural Data Units"
261:internal fragmentation
254:, which is a level of
43:Bank (computer memory)
39:Page (computer memory)
569:Computer data storage
495:"Physical Structures"
168:, sometimes called a
307:storage area network
72:improve this article
32:Blocking (computing)
394:, are listed below.
335:Blaauw, Gerrit Anne
172:, is a sequence of
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70:Please help
65:verification
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265:slack space
256:abstraction
214:data stream
206:data buffer
563:Categories
529:2013-03-29
504:2014-04-29
499:Captain SK
479:2014-04-29
450:computer.)
383:2017-04-03
321:References
237:hard disks
202:deblocking
190:structured
186:block size
128:April 2014
98:newspapers
18:Data block
428:Word size
404:character
295:block I/O
154:computing
441:GAMMA 60
374:archived
370:61-10466
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210:overhead
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198:blocking
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273:FreeBSD
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299:SCSI
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160:and
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416:bit
391:bit
315:AoE
301:or
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