|ESRL training calendar | member libraries | contact us | home|
It is meeting your own specifications and meeting your customers expectations. It is also concerned with doing the right things and doing things right.
A request that specifies the manner in which data is to be extracted from one or more databases.
A sequence of stored computer data or programs awaiting processing that are processed in the order first-in first-out (FIFO).
Ends the work without writing out a new file or new version of the exiting work file unless there is a save that interrupts before dumping the session.
Redundant Array of Inexpensive Disks. A way of creating a fault-tolerant storage system. There are 6 levels. Level 0 uses byte-level striping. Level 1 uses mirroring. Level 2 uses bit-level striping. Level 3 stores error correcting information (such as parity) on a separate disk, and uses data striping on the remaining drives. Level 4 is level 3 with block level striping. Level 5 uses block level and parity data striping.
Random Access Memory. Memory in which each element can be individually addressed and accessed with the same speed as any other element of the memory. The main memory of a computer is usually RAM. One of the earliest forms of RAM was called core, because it consisted of directly addressed doughnuts or cores of ferromagnetic material each of which represented one bit. A faster more recent form of RAM is called Dynamic RAM.
Differs from direct access by the fact that each element can be accessed with the same ease and speed as any other.
To sense and retrieve or interpret data from a form of storage or input medium.
A magnetic mechanism that can read, write and erase data encoded as polarized patterns on magnetic disk or tape.
The processing of transactions as they occur rather than batching them. Pertaining to an application in which response to input is fast enough to affect subsequent inputs and guide the process and in which records are updated immediately. The lag from input time to output time must be sufficiently small for acceptable timeliness. Timeliness is a function of the total system: missile guidance requires output within a few milliseconds of input, scheduling of steamships requires response time in days. Realtime systems are those with response time of milliseconds, interactive system in seconds and batch system in hours or days.
A collection of related data or words, treated as a unit. For example, in stock control, each invoice could constitute one record.
Depending on the context, the length in bytes (i.e., columns) of a physical record or a logical record . On ICPSR Tape Information Forms and on CDNet, the abbreviation "RecLen" is used for physical record length.
A record that has a consistent logical structure. In files that include different units of analysis, for instance, different record types are needed to hold the different variables. For example, one record type might have a variable for income in one column and another record type might have a variable for household size in that same column. The codebook will describe these different structures and how to determine which is which so that you can tell your statistical software how to interpret that particular column as income or household size.
The process by which data bases are rebuilt after a system fails.
One-half inch magnetic tape stored on round reels. Also called Round Tape.
An organization of data into tables with each column containing the values of a data element and each row representing a record.
A study that includes different units of analysis, particularly when those units are not arranged in a strict hierarchy as they are in a hierarchical file, has a relational structure. Note that the data could be arranged in several different physical structures to handle such a data structure. For instance, each unit of analysis might be stored in a separate rectangular file with identification numbers linking each case to the other units; or, the different units of analysis might be stored in one large file with a hierarchical file structure; or the different units could be stored in a special database structure used by a relational data base management system such as INGRES. An example of a study with a relational structure is the Survey of Income and Program Participation which has eight or more record types; these record types are related to each other but are not all members of a hierarchy of membership. For instance, there are record types for household, family, person, wage and salary job, and general income amounts.
Equipment or site that is located out of the way or at a distance from primary equipment or a larger or primary site. Sometimes used as the opposite of local.
The ability to access a computer from outside a building in which it is housed. Remote access requires communications hardware, software, and actual physical links, although this can be as simple as common carrier (telephone) lines or as complex as TELNET login to another computer across the Internet.
An on-line information set or an on-line interactive option. An on-line library catalog or the local school lunch menu are examples of information sets. On-line menus or graphical user interfaces, Internet e-mail, on-line conferences, telnet, FTP, and Gopher are examples of interactive options.
A message placed in a conference as a follow-up to a topic or to another response; or, a reply to an e-mail message.
The key on a terminal keyboard that, when struck, places the cursor at the left margin one line below its previous horizontal position.
The process of going from the more concrete level of code to the more abstract level of models for data and processes.
Read-only memory. Information is stored once, usually by the manufacturer, that cannot be changed. Most compact discs are ROM.
The directory that contains all other directories.
A device connecting separate networks that forwards a packet from one network to another based only on the network address for the protocol being used. For example, an IP router looks only at the IP network number.
Part of a computer program, or a sequence of instructions called by a program, that may have some general or frequent use.
The process of finding a path over which a packet can travel to reach its destination.
The single, continuous execution of a program by a computer on a given set of data. As a verb, to initiate processing by a program.
122-126 S. Division St. Salisbury, MD 21801