SQL/MP Glossary

Glossary
Compaq NonStop™ SQL/MP Glossary—429832-001
Glossary-24
range of DATETIME fields
range of DATETIME fields. The subset of fields that compose a value of type DATETIME,
DATE, TIME, or TIMESTAMP; also called a datetime qualifier. Some sample ranges
are YEAR TO DAY, HOUR TO SECOND, and MONTH TO MINUTE.
range of INTERVAL fields. The subset of fields that compose a value of type INTERVAL.
The range can include either year-month or day-time fields, but not both. Some sample
ranges are YEAR, DAY TO HOUR, and MINUTE TO SECOND.
Real Sequential Block Buffering. See RSBB (Real Sequential Block Buffering)
.
recompilation. See automatic SQL recompilation
or explicit SQL compilation.
record. A unit of data that can be read from or written to a file; a record is represented as a
row in a relational table.
recovery. Returning a database file or files to a current, consistent state.
redefinition timestamp. The timestamp of an SQL object that indicates the most recent time
when a compilation occurred or an invalidating operation was performed on the object.
See also timestamp check
.
relational database. A database in which data is represented as relational tables from which
users can select data by performing projections, restrictions, and joins.
relative file. A file in which each new record is stored at the relative record location specified
by its primary key. Records stored in a relative file can be updated or deleted. Contrast
with entry-sequenced file
and key-sequenced file.
relative table. A table stored in a relative file and whose primary key is a user-defined or
system-defined relative record number. Columns can be added to a relative table
(provided the original record length is large enough), rows can be updated or deleted,
and variable-length character values can be lengthened or shortened. Contrast with
entry-sequenced table
and key-sequenced table.
Reload Analyzer tool. A Compaq product for identifying and prioritizing database files and
tables that need to be reorganized.
repeatable access. An access option for transaction consistency that ensures that the data
accessed by a transaction cannot be changed by other users until the transaction ends.
With repeatable access, a process tests for existing locks on data before acquiring its
own lock and holds the lock until the transaction completes. Of the access options,
repeatable access provides the highest consistency but the lowest concurrency. Contrast
with browse access
and stable access.
repeatable read. The level of consistency that repeatable access provides. Contrast with
cursor stability
. See also repeatable access.
report. A formatted listing of data retrieved by a query. A formatted report can be defined
with the SQLCI report writer.