In computer technology, fetch has several meanings related to getting, reading, or moving data objects.
1) Fetch is the first of two stages involved in computer processing. The processor operates by processing instructions in what is called the "fetch/execute cycle." The processor fetches (reads from memory) an instruction and then, depending on the instruction, executes it (takes some further action with it, such as shifting bits to the right or left). Then it fetches the next instruction, and so forth.
A register in the processor called the program counter holds information about where the processor is in the particular program being processed and the address (location) of the next instruction to be executed. At the beginning of the cycle, the program counter tells the processor which instruction to fetch; during the cycle, the instruction is executed and the information is updated to refer to the next instruction to be fetched.
In some newer processor designs, more than one instruction can be fetched at the same time and execution is done in parallel.
2) Fetch is a command used in embedded Structured Query Language (SQL) to retrieve rows sequentially. In SQL, a cursor is a pointer to a selected row in a collection retrieved by a SQL statement. The cursor advances through the rows, one at a time, to allow sequential processing of records. The fetch command retrieves the selected row from the cursor. The steps involved in using the fetch command are: Declare cursor, Open cursor, Fetch row (separate fetches may be executed for multiple rows) and Close cursor.
3) Fetch is a Macintosh program for transferring files between any networked Macintosh computers using the File Transfer Protocol (FTP). Its features include support of multiple connections, the capacity to restart interrupted transfers, and drag-and-drop functionality for transferring, bookmarking, and preference setting.