Do not enable these extensions unless you're certain that they will always be available on any machine that will run your program. The BOOST_UUID_USE_SSE* macros can be defined by users, if auto-detection fails and it is known that the target CPU will have the extension. If defined, enables optimizations for SSE4.1 exstensions available in modern x86 processors.īy default the library attempts to detect the availability of SIMD extensions in the target CPU at compile time and automatically defines the appropriate macros if succeeded. If defined, enables optimizations for SSE3 exstensions available in modern x86 processors. If defined, enables optimizations for SSE2 exstensions available in modern x86 processors. By default, optimized algorithms are used, when the library is able to detect the availability of SIMD extensions at compile time. This may result in suboptimal performance. Generic versions of algorithms will be used instead. If defined, disables any optimizations for SIMD-enabled processors. These macros are summarized in the following table. However, there are a few options that can be enabled by defining macros prior to
The library does not require building or any special configuration to be used. Never be generated again), or it is extremely likely to be unique (depending Generated UUIDs (that is, it has never been generated before and it will Mechanisms, they are either guaranteed to be unique, different from all other When UUIDs are generated by one of the defined Another is that the creation of UUIDsĭoes not require a centralized authority. UUIDs are also a basisįor OIDs (object identifiers), and URNs (uniform resource name).Īn attractive feature of UUIDs when compared to alternatives is their relative Video streams in the Advanced Systems Format (ASF). UUIDs are inserted intoĭocuments from Microsoft Office programs.
LINUX UUID GENERATOR SOFTWARE
Microsoft's component object model (COM) uses UUIDs toĭistinguish different software component interfaces. Transactions and classes involved in serialization may be Distributed computing may use UUIDs to identify a remote May be identified with a UUID to ensure that different parts of a message are putīack together again. To identify rows or records in order to ensure that they are unique acrossĭifferent databases, or for publication/subscription services. Some examples follow: Databases may use UUIDs To reliably identify very persistent objects across a network.Ī formal definition for UUID can be found in RFC 4122.
It can be used to tag objects with very short lifetimes, or Information in a distributed environment without significant centralĬoordination. Uuid ContentsĪ UUID, or Universally unique identifier, is intended to uniquely identify For example the uuid-ossp module provides some handy functions that implement standard algorithms for generating UUIDs.This is the documentation for an old version of Boost.Ĭlick here to view this page for the latest version. Instead, it relies on the third-party modules that provide specific algorithms to generate UUIDs. PostgreSQL allows you store and compare UUID values but it does not include functions for generating the UUID values in its core.
To stores UUID values in the PostgreSQL database, you use the UUID data type.
LINUX UUID GENERATOR SERIAL
Code language: SQL (Structured Query Language) ( sql )Īs you can see, a UUID is a sequence of 32 digits of hexadecimal digits represented in groups separated by hyphens.īecause of its uniqueness feature, you often found UUID in the distributed systems because it guarantees a better uniqueness than the SERIAL data type which generates only unique values within a single database.
0 kommentar(er)
