The following table lists the logical names that SQL recognizes
for special purposes.
Table 1 Summary of SQL Logical Names
Logical Name Function
RDB$CHARACTER_SET Specifies the database default and
national character sets in addition
to the session default, identifier,
literal, and national character sets.
The logical name is used by the
EXPORT and IMPORT statements and
by the SQL precompiler and SQL module
language to allow compatibility of
most recent versions with earlier
versions of Oracle Rdb. This logical
name sets the attributes for the
default connection.
This logical name is also deprecated
and will not be supported in a future
release.
RDB$LIBRARY Specifies a protected library that
you can use to store external routine
images, such as external functions.
Oracle Rdb recommends that you manage
public or sensitive external routine
images using a protected library
that is referenced by the logical
name RDB$LIBRARY. You should define
RDB$LIBRARY as an executive mode
logical name in the system logical
name table. If the external routine
image is located in the protected
area, you can ensure that the desired
image is used by specifying the
RDB$LIBRARY logical name with an
explicit file name in the LOCATION
clause plus the WITH SYSTEM LOGICAL_
NAME TRANSLATION clause in a CREATE
FUNCTION statement.
RDB$RDBSHR_EVENT_FLAGS Can be used to override the four
event flag numbers that are assigned
to RDB$SHARE at startup time by the
LIB$GET_EF system service.
RDB$REMOTE_BUFFER_SIZE Changes the default buffer size,
up to your system quota limits, of
network transfers. This can reduce
the number of network I/O operations
used during large transfers.
Restrictions apply, depending on
which version of Oracle Rdb you are
using.
RDB$REMOTE_MULTIPLEX_OFF Disables the multiplex feature.
RDB$ROUTINES Specifies the location of an external
routine image. If you do not specify
a location clause in a CREATE
FUNCTION, CREATE PROCEDURE, or CREATE
MODULE statement, or if you specify
the DEFAULT LOCATION clause, SQL uses
the RDB$ROUTINES logical name as the
default image location.
RDMS$BIND_OUTLINE_MODE When multiple outlines exist for a
query, this logical name is defined
to select which outline to use.
RDMS$BIND_QG_CPU_TIMEOUT Specifies the amount of CPU time used
to optimize a query for execution.
RDMS$BIND_QG_REC_LIMIT Specifies the number of rows that
SQL fetches before the query governor
stops output.
RDMS$BIND_QG_TIMEOUT Specifies the number of seconds that
SQL spends compiling a query before
the query governor aborts that query.
RDMS$BIND_SEGMENTED_ Allows you to reduce the overhead of
STRING_BUFFER I/O operations at run time when you
are manipulating a segmented string.
RDMS$DEBUG_FLAGS Allows you to examine database access
strategies and the estimated cost of
those strategies when your program
runs.
RDMS$SET_FLAGS Allows you to examine database access
strategies and the estimated cost of
those strategies when your program
runs. See the SET FLAGS statement for
a list of valid keywords that can be
used with this logical name.
RDMS$DIAG_FLAGS When defined to 'L', prevents the
opening of a scrollable list cursor
when the online format of lists is
chained.
RDMS$RTX_SHRMEM_PAGE_CNT Specifies the size of the shared
memory area used to manipulate
server site-bound, external routine
parameter data and control data.
RDMS$USE_ Allows applications to use the
OLD_CONCURRENCY isolation-level behavior that was
in effect for V4.1.
RDMS$USE_OLD_SEGMENTED_ When defined to YES, the default
STRING online format for lists (segmented
strings) is chained.
RDMS$VALIDATE_ROUTINE Controls the validation of routines.
SQL$DATABASE Specifies the database that SQL
declares if you do not explicitly
declare a database.
SQL$DISABLE_CONTEXT Disables the two-phase commit
protocol. Useful for turning off
distributed transactions when
you want to run batch-update
transactions.
SQL$EDIT Specifies the editor that SQL invokes
when you issue the EDIT statement in
interactive SQL.
SQLINI Specifies the command file that SQL
executes when you invoke interactive
SQL.
SYS$CURRENCY Specifies the character that SQL
substitutes for the dollar sign ($)
symbol in an EDIT STRING clause of
a column or domain definition, or
the EDIT USING clause of a SELECT
statement.
SYS$DIGIT_SEP Specifies the character that SQL
substitutes for the comma symbol (,)
in an EDIT STRING clause of a column
or domain definition, or the EDIT
USING clause of a SELECT statement.
SYS$LANGUAGE Specifies the language that SQL uses
for date and time input and displays,
or the EDIT USING clause of a SELECT
statement.
SYS$RADIX_POINT Specifies the character that SQL
substitutes for the decimal point
symbol (.) in an EDIT STRING clause
of a column or domain definition,
or the EDIT USING clause of a SELECT
statement.
The following table shows the valid equivalence names for the
logical name RDB$CHARACTER_SET.
Table 2 Valid Equivalence Names for RDB$CHARACTER_SET Logical
Name
Name of Character
Character Set Set Equivalence Name
MCS DEC_MCS Undefined
Korean and ASCII DEC_KOREAN DEC_HANGUL
Hanyu and ASCII DEC_HANYU DEC_HANYU
Hanzi and ASCII DEC_HANZI DEC_HANZI
Kanji and ASCII DEC_KANJI DEC_KANJI
For more information on these and other logical names, see the
Oracle Rdb7 Guide to Database Performance and Tuning.