Search results
Results from the WOW.Com Content Network
Indexed Sequential Access Method (ISAM) is a method for creating, maintaining, and manipulating computer files of data so that records can be retrieved sequentially or randomly by one or more keys. Indexes of key fields are maintained to achieve fast retrieval of required file records in indexed files .
The key must be such that it uniquely identifies a record. If more than one index is present the other ones are called alternate indexes. The indexes are created with the file and maintained by the system. IBM supports indexed files with the Indexed Sequential Access Method on OS/360 and successors.
Sequential access compared to random access. Sequential access is a term describing a group of elements (such as data in a memory array or a disk file or on magnetic-tape data storage) being accessed in a predetermined, ordered sequence. It is the opposite of random access, the ability to access an arbitrary element of a sequence as easily and ...
Another one of the modules contains the ISAM Drivers, DLLs that allow access to a variety of Indexed Sequential Access Method ISAM databases, among them xBase, Paradox, Btrieve and FoxPro, depending on the version of Jet. The final module is the Data Access Objects (DAO) DLL. [2]
Time taken to access any record is the same because the same number of nodes is searched; Index is a full index so data file does not have to be ordered; Pros and cons versatile data structure – sequential as well as random access; access is fast; supports exact, range, part key and pattern matches efficiently.
While backwards compatibility was maintained, the older access methods suffered from performance problems due to the address translation required for virtual storage. The KSDS organization was designed to replace ISAM, the Indexed Sequential Access Method. Changes in disk technology had meant that searching for data in ISAM data sets had become ...
Queued sequential access method (QSAM) Queued indexed sequential access method (QISAM) Basic partitioned access method (BPAM) Basic direct access method (BDAM) Virtual storage access method (VSAM) Execute Channel Program (EXCP) Execute Channel Program in Real Storage (EXCPVR) In MVS, starting with OS/VS2 Release 2 and continuing through z/OS ...
Extensible Storage Engine (ESE), also known as JET Blue, is an ISAM (indexed sequential access method) data storage technology from Microsoft. ESE is the core of Microsoft Exchange Server, Active Directory, and Windows Search. It is also used by a number of Windows components including Windows Update client and Help and Support Center. Its ...