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Core Data
Core Data is an object graph and persistence framework provided by Apple in the macOS and iOS operating systems. It was introduced in Mac OS X 10.4 Tiger and iOS with iPhone SDK 3.0.Apple, "Core Data Tutorial for iPhone OS". It allows data organized by the relational entity–attribute model to be serialized into XML, binary, or SQLite stores. The data can be manipulated using higher level objects representing entities and their relationships. Core Data manages the serialized version, providing object lifecycle and object graph management, including persistence. Core Data interfaces directly with SQLite, insulating the developer from the underlying SQL.Apple, "Core Data Programming Guide". Just as Cocoa Bindings handle many of the duties of the controller in a model–view–controller design, Core Data handles many of the duties of the data model. Among other tasks, it handles change management, serializing to disk, memory footprint minimization and queries against the d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Macosx Data Coredata 20090925
macOS (; previously OS X and originally Mac OS X) is a Unix operating system developed and marketed by Apple Inc. since 2001. It is the primary operating system for Apple's Mac (computer), Mac computers. Within the market of desktop and laptop computers it is the Usage share of operating systems#Desktop and laptop computers, second most widely used desktop OS, after Microsoft Windows and ahead of ChromeOS. macOS succeeded the classic Mac OS, a Mac operating system with nine releases from 1984 to 1999. During this time, Apple cofounder Steve Jobs had left Apple and started another company, NeXT Computer, NeXT, developing the NeXTSTEP platform that would later be acquired by Apple to form the basis of macOS. The first desktop version, Mac OS X 10.0, was released in March 2001, with its first update, 10.1, arriving later that year. All releases from Mac OS X Leopard, Mac OS X 10.5 Leopard and after are UNIX 03 certified, with an exception for OS X Lion, OS X 10. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Persistence (computer Science)
In computer science, persistence refers to the characteristic of state of a system that outlives (persists more than) the process that created it. This is achieved in practice by storing the state as data in computer data storage. Programs have to transfer data to and from storage devices and have to provide mappings from the native programming-language data structures to the storage device data structures. Picture editing programs or word processors, for example, achieve state persistence by saving their documents to files. Orthogonal or transparent persistence Persistence is said to be " orthogonal" or "transparent" when it is implemented as an intrinsic property of the execution environment of a program. An orthogonal persistence environment does not require any specific actions by programs running in it to retrieve or save their state. Non-orthogonal persistence requires data to be written and read to and from storage using specific instructions in a program, resulting in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Schema Migration
In software engineering, a schema migration (also database migration, database change management) refers to the management of version-controlled, incremental and reversible changes to relational database schemas. A schema migration is performed on a database whenever it is necessary to update or revert that database's schema to some newer or older version. Migrations are performed programmatically by using a ''schema migration tool''. When invoked with a specified desired schema version, the tool automates the successive application or reversal of an appropriate sequence of schema changes until it is brought to the desired state. Most schema migration tools aim to minimize the impact of schema changes on any existing data in the database. Despite this, preservation of data in general is not guaranteed because schema changes such as the deletion of a database column can destroy data (i.e. all values stored under that column for all rows in that table are deleted). Instead, the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ODBC Framework
In computing, Open Database Connectivity (ODBC) is a standard application programming interface (API) for accessing database management systems (DBMS). The designers of ODBC aimed to make it independent of database systems and operating systems. An application written using ODBC can be ported to other platforms, both on the client and server side, with few changes to the data access code. ODBC accomplishes DBMS independence by using an ''ODBC driver'' as a translation layer between the application and the DBMS. The application uses ODBC functions through an ''ODBC driver manager'' with which it is linked, and the driver passes the query to the DBMS. An ODBC driver can be thought of as analogous to a printer driver or other driver, providing a standard set of functions for the application to use, and implementing DBMS-specific functionality. An application that can use ODBC is referred to as "ODBC-compliant". Any ODBC-compliant application can access any DBMS for which a driver is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Enterprise Objects Framework
The Enterprise Objects Framework, or more commonly simply EOF, was introduced by NeXT in 1994 as a pioneering object-relational mapping product for its NeXTSTEP and OpenStep development platforms. EOF abstracts the process of interacting with a relational database by mapping database rows to Java or Objective-C objects. This largely relieves developers from writing low-level SQL code. EOF enjoyed some niche success in the mid-1990s among financial institutions who were attracted to the rapid application development advantages of NeXT's object-oriented platform. Since Apple Inc's merger with NeXT in 1996, EOF has evolved into a fully integrated part of WebObjects, an application server also originally from NeXT. Many of the core concepts of EOF re-emerged as part of Core Data, which further abstracts the underlying data formats to allow it to be based on non-SQL stores. History In the early 1990s NeXT Computer recognized that connecting to databases was essential to most busine ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Atomic (computer Science)
In concurrent programming, an operation (or set of operations) is linearizable if it consists of an ordered list of invocation and response events (event), that may be extended by adding response events such that: # The extended list can be re-expressed as a sequential history (is serializable). # That sequential history is a subset of the original unextended list. Informally, this means that the unmodified list of events is linearizable if and only if its invocations were serializable, but some of the responses of the serial schedule have yet to return. In a concurrent system, processes can access a shared object at the same time. Because multiple processes are accessing a single object, there may arise a situation in which while one process is accessing the object, another process changes its contents. Making a system linearizable is one solution to this problem. In a linearizable system, although operations overlap on a shared object, each operation appears to take place i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dirty (computer Science)
In computing, a cache ( ) is a hardware or software component that stores data so that future requests for that data can be served faster; the data stored in a cache might be the result of an earlier computation or a copy of data stored elsewhere. A ''cache hit'' occurs when the requested data can be found in a cache, while a ''cache miss'' occurs when it cannot. Cache hits are served by reading data from the cache, which is faster than recomputing a result or reading from a slower data store; thus, the more requests that can be served from the cache, the faster the system performs. To be cost-effective and to enable efficient use of data, caches must be relatively small. Nevertheless, caches have proven themselves in many areas of computing, because typical computer applications access data with a high degree of locality of reference. Such access patterns exhibit temporal locality, where data is requested that has been recently requested already, and spatial locality, where d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Swift (programming Language)
Swift is a general-purpose, multi-paradigm, compiled programming language developed by Apple Inc. and the open-source community. First released in 2014, Swift was developed as a replacement for Apple's earlier programming language Objective-C, as Objective-C had been largely unchanged since the early 1980s and lacked modern language features. Swift works with Apple's Cocoa and Cocoa Touch frameworks, and a key aspect of Swift's design was the ability to interoperate with the huge body of existing Objective-C code developed for Apple products over the previous decades. It was built with the open source LLVM compiler framework and has been included in Xcode since version 6, released in 2014. On Apple platforms, it uses the Objective-C runtime library, which allows C, Objective-C, C++ and Swift code to run within one program. Apple intended Swift to support many core concepts associated with Objective-C, notably dynamic dispatch, widespread late binding, extensible programming ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Objective-C
Objective-C is a general-purpose, object-oriented programming language that adds Smalltalk-style messaging to the C programming language. Originally developed by Brad Cox and Tom Love in the early 1980s, it was selected by NeXT for its NeXTSTEP operating system. Due to Apple macOS’s direct lineage from NeXTSTEP, Objective-C was the standard programming language used, supported, and promoted by Apple for developing macOS and iOS applications (via their respective APIs, Cocoa and Cocoa Touch) until the introduction of the Swift programming language in 2014. Objective-C programs developed for non-Apple operating systems or that are not dependent on Apple's APIs may also be compiled for any platform supported by GNU GCC or LLVM/Clang. Objective-C source code 'messaging/implementation' program files usually have filename extensions, while Objective-C 'header/interface' files have extensions, the same as C header files. Objective-C++ files are denoted with a file extension. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Xcode
Xcode is Apple's integrated development environment (IDE) for macOS, used to develop software for macOS, iOS, iPadOS, watchOS, and tvOS. It was initially released in late 2003; the latest stable release is version 14.2, released on December 13, 2022, via the Mac App Store with macOS Monterey. The software suite is offered free of charge. Registered developers can download preview releases and prior versions of the suite through the Apple Developer website. Xcode includes command-line tools which enable UNIX-style development via the Terminal app in macOS. They can also be downloaded and installed without the GUI. Major features Xcode supports source code for the programming languages: C, C++, Objective-C, Objective-C++, Java, AppleScript, Python, Ruby, ResEdit (Rez), and Swift, with a variety of programming models, including but not limited to Cocoa, Carbon, and Java. Third parties have added support for GNU Pascal, Free Pascal, Ada, C#, Go, Perl, and D. Xcode can build ' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Database Schema
The database schema is the structure of a database described in a formal language supported by the database management system (DBMS). The term "schema" refers to the organization of data as a blueprint of how the database is constructed (divided into database tables in the case of relational databases). The formal definition of a database schema is a set of formulas (sentences) called integrity constraints imposed on a database. These integrity constraints ensure compatibility between parts of the schema. All constraints are expressible in the same language. A database can be considered a structure in realization of the database language. The states of a created conceptual schema are transformed into an explicit mapping, the database schema. This describes how real-world entities are modeled in the database. "A database schema specifies, based on the database administrator's knowledge of possible applications, the facts that can enter the database, or those of interest to the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
VCard
vCard, also known as VCF (Virtual Contact File), is a file format standard for electronic business cards. vCards can be attached to e-mail messages, sent via Multimedia Messaging Service (MMS), on the World Wide Web, instant messaging, NFC or through QR code. They can contain name and address information, phone numbers, e-mail addresses, URLs, logos, photographs, and audio clips. vCard is used as data interchange format in smartphone contacts, personal digital assistants (PDAs), personal information managers (PIMs) and customer relationship management (CRMs). To accomplish these data interchange applications, other "vCard variants" have been used and proposed as "variant standards", each for its specific niche: XML representation, JSON representation, or web pages. An unofficial vCard Plus format makes use of a URL to a customized landing page with all the basic information along with a profile photo, geographic location, and other fields. This can also be saved as a conta ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
