Oracle8i SQL Reference Release 2 (8.1.6) A76989-01 |
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SQL Statements (continued), 2 of 8
filespec_datafiles & filespec_tempfiles::=
filespec_redo_log_file_groups::=
To specify a file as a datafile or tempfile
To specify a group of one or more files as a redo log file group.
A filespec can appear in the following statements: "CREATE DATABASE", "ALTER DATABASE", "CREATE TABLESPACE", and "ALTER TABLESPACE", "CREATE CONTROLFILE", "CREATE LIBRARY", and "CREATE TEMPORARY TABLESPACE".
You must have the privileges necessary to issue one of these statements.
The following statement creates a database named PAYABLE
that has two redo log file groups, each with two members, and one datafile:
CREATE DATABASE payable LOGFILE GROUP 1 ('diska:log1.log', 'diskb:log1.log') SIZE 50K, GROUP 2 ('diska:log2.log', 'diskb:log2.log') SIZE 50K DATAFILE 'diskc:dbone.dat' SIZE 30M;
The first filespec in the LOGFILE
clause specifies a redo log file group with the GROUP
value 1. This group has members named 'diska:log1.log
' and 'diskb:log1.log
', each 50 kilobytes in size.
The second filespec in the LOGFILE
clause specifies a redo log file group with the GROUP
value 2. This group has members named 'diska:log2.log
' and 'diskb:log2.log
', also 50 kilobytes in size.
The filespec in the DATAFILE
clause specifies a datafile named 'diskc:dbone.dat
', 30 megabytes in size.
All of these filespecs specify a value for the SIZE
parameter and omit the REUSE
clause, so none of these files can already exist. Oracle must create them.
The following statement adds another redo log file group with two members to the PAYABLE
database:
ALTER DATABASE payable ADD LOGFILE GROUP 3 ('diska:log3.log', 'diskb:log3.log') SIZE 50K REUSE;
The filespec in the ADD
LOGFILE
clause specifies a new redo log file group with the GROUP
value 3. This new group has members named 'diska:log3.log'
and 'diskb:log3.log'
, each 50 kilobytes in size. Because the filespec specifies the REUSE
clause, each member can already exist. If a member exists, it must have a size of 50 kilobytes. If it does not exist, Oracle creates it with that size.
The following statement creates a tablespace named STOCKS
that has three datafiles:
CREATE TABLESPACE stocks DATAFILE 'diskc:stock1.dat', 'diskc:stock2.dat', 'diskc:stock3.dat';
The filespecs for the datafiles specifies files named 'diskc:stock1.dat'
, 'diskc:stock2.dat'
, and 'diskc:stock3.dat'
. Since each filespec omits the SIZE
parameter, each file must already exist.
The following statement alters the STOCKS
tablespace and adds a new datafile:
ALTER TABLESPACE stocks ADD DATAFILE 'diskc:stock4.dat' REUSE;
The filespec specifies a datafile named 'diskc:stock4.dat'
. Since the filespec omits the SIZE
parameter, the file must already exist and the REUSE
clause is not significant.
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