Unraveling a relational database into a sequential file
not only mutes the efficiency of the software's design and operation, but it can create an annual file that is so large that there may not be a system capable of processing it.
Note: The process to create a sequential file
should be reviewed by the IRS prior to destruction of the DBMS records.
You can use a list processor, which is a simple-minded database manager that works with sequential files
. It will allow you to enter, delete, and correct information.
Figures 2 and 3 show elapsed times for sequential file creation and reading, respectively.
This is somewhate surprising since the sequential file access experiments seem to indicate that the IBMCACHE as not having any advantage at all unless the file was read more than once.
Although several of these languages do contain important new features, they lack certain basic facilities for business programming that Cobol programmers have long taken for granted: features like standardized file access, built-in SORT, indexed sequential files
, explicit precision arithmetic with up to 18 digits, and powerful output formatting.
* For tax documentation maintained on DBMS systems, taxpayers must retain "sequential files
containing the details necessary to identify the underlying source documents," as well as systems documentation sufficient to support audit requirements and demonstrate the integrity of the records.
"You're required to keep a permanent record of every policy ever written and every loss ever paid, so we have enormous sequential files
with all these data.
originated with decks of data punch cards that were sequentially processed by the computer.
In either case, the data must be in the form of small sequential or near sequential files
such as those found in some video editing applications.
Large sequential files
with moderate or archival access levels may be best suited for removable tape storage libraries.
Tape automation first became popular in the mainframe environment as a means to control tape mounting operations for large numbers of sequential files
. Within the open systems environment, tape libraries appeared to automate the backup process by eliminating operator intervention and the resulting errors of manual handling.