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19-570: VLDB may refer to: Very large databases VLDB conference , an annual database conference Topics referred to by the same term [REDACTED] This disambiguation page lists articles associated with the title VLDB . If an internal link led you here, you may wish to change the link to point directly to the intended article. Retrieved from " https://en.wikipedia.org/w/index.php?title=VLDB&oldid=908731671 " Category : Disambiguation pages Hidden categories: Short description

38-410: A memory fetch, to a disk IO, to a complex database query, or loading a full web page. Ignoring transmission time for a moment, the response time is the sum of the service time and wait time. The service time is the time it takes to do the work you requested. For a given request the service time varies little as the workload increases – to do X amount of work it always takes X amount of time. The wait time

57-481: A VESA industry standard from the 10% to the 90% points in the pixel response curve. In fast paced competitive games such as Counter-Strike , the response time of a display is crucial for optimal performance. Displays that have a lower response time are more responsive to player input and produce less visual errors when displaying a rapidly changing image, making low response time important for competitive gaming . Most modern monitors that are marketed for gaming have

76-423: A VLDB can increase exponentially for the database administrator as database size increases. When dealing with VLDB operations relating to maintenance and recovery such as database reorganizations and file copies which were quite practical on a non-VLDB take very significant amounts of time and resources for a VLDB database. In particular it typically infeasible to meet a typical recovery time objective (RTO),

95-418: A VLDB the database storage needs to have low access latency and contention , high throughput , and high availability . The increasing size of a VLDB may put pressure on server and network resources and a bottleneck may appear that may require infrastructure investment to resolve. VLDB is not the same as big data , but the storage aspect of big data may involve a VLDB database. That said some of

114-413: A broad and subjective interpretation, but attempts at defining a metric and threshold have been made. Early metrics were the size of the database in a canonical form via database normalization or the time for a full database operation like a backup . Technology improvements have continually changed what is considered very large . One definition has suggested that a database has become a VLDB when it

133-451: A network and it can be very significant. Transmission time can include propagation delays due to distance (the speed of light is finite), delays due to transmission errors , and data communication bandwidth limits (especially at the last mile ) slowing the transmission speed of the request or the reply. Developers can reduce the response time of a system (for end users or not) using program optimization techniques. In real-time systems

152-482: Is "too large to be maintained within the window of opportunity… the time when the database is quiet". There is no absolute amount of data that can be cited. For example, one cannot say that any database with more than 1 TB of data is considered a VLDB. This absolute amount of data has varied over time as computer processing, storage and backup methods have become better able to handle larger amounts of data. That said, VLDB issues may start to appear when 1 TB

171-469: Is approached, and are more than likely to have appeared as 30 TB or so is exceeded. Key areas where a VLDB may present challenges include configuration, storage, performance, maintenance, administration, availability and server resources. Careful configuration of databases that lie in the VLDB realm is necessary to alleviate or reduce issues raised by VLDB databases. The complexities of managing

190-436: Is different from Wikidata All article disambiguation pages All disambiguation pages Very large database A very large database , (originally written very large data base ) or VLDB , is a database that contains a very large amount of data, so much that it can require specialized architectural, management, processing and maintenance methodologies. The vague adjectives of very and large allow for

209-417: Is how long the request had to wait in a queue before being serviced and it varies from zero, when no waiting is required, to a large multiple of the service time, as many requests are already in the queue and have to be serviced first. With basic queueing theory math you can calculate how the average wait time increases as the device providing the service goes from 0-100% busy. As the device becomes busier,

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228-418: The average wait time increases in a non-linear fashion. The busier the device is, the more dramatic the response time increases will seem as you approach 100% busy; all of that increase is caused by increases in wait time, which is the result of all the requests waiting in queue that have to run first. Transmission time gets added to response time when your request and the resulting response has to travel over

247-628: The context of the specific system. And it has a relation to the TTFB , which is the time between the dispatch and the time when the response starts. Response time is the amount of time a pixel in a display takes to change. It is measured in milliseconds (ms). Lower numbers mean faster transitions and therefore fewer visible image artifacts. Display monitors with long response times would create display motion blur around moving objects, making them unacceptable for rapidly moving images. Response times are usually measured from grey-to-grey transitions, based on

266-469: The indexes used to access data may grow slightly in height requiring perhaps an extra storage access to reach the data ( sub-linear time ). Other effects can be caching becoming less efficient because proportionally less data can be cached and while some indexes such as the B+ automatically sustain well with growth others such as a hash table may need to be rebuilt. Should an increase in database size cause

285-547: The maximum expected time a database is expected to be unavailable due to interruption, by methods which involve copying files from disk or other storage archives. To overcome these issues techniques such as clustering, cloned/replicated/standby databases, file-snapshots, storage snapshots or a backup manager may help achieve the RTO and availability, although individual methods may have limitations, caveats, license, and infrastructure requirements while some may risk data loss and not meet

304-585: The number of accessors of the database to increase then more server and network resources may be consumed, and the risk of contention will increase. Some solutions to regaining performance include partitioning , clustering , possibly with sharding , or use of a database machine . Partitioning may be able assist the performance of bulk operations on a VLDB including backup and recovery., bulk movements due to information lifecycle management (ILM), reducing contention as well as allowing optimization of some query processing. In order to satisfy needs of

323-518: The recovery point objective (RPO). For many systems only geographically remote solutions may be acceptable. Best practice is for backup and recovery to be architectured in terms of the overall availability and business continuity solution. Given the same infrastructure there may typically be a decrease in performance, that is increase in response time as database size increases. Some accesses will simply have more data to process (scan) which will take proportionally longer ( linear time ); while

342-420: The response time of a task or thread is defined as the time elapsed between the dispatch (time when task is ready to execute) to the time when it finishes its job (one dispatch). Response time is different from WCET which is the maximum time the task would take if it were to execute without interference. It is also different from deadline which is the length of time during which the task's output would be valid in

361-447: The storage solutions supporting big data were designed from the start to support large volumes of data, so database administrators may not encounter VLDB issues that older versions of traditional RDBMS 's might encounter. Response time (technology) In computing, the responsiveness of a service, how long a system takes to respond to a request for service, is measured through the response time. That service can be anything from

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