Database Reference
In-Depth Information
As expected, read permission is granted solely to the owner of the file and the group
“oinstall”.
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If a server parameter file (
SPFILE
) is used,
_TRACE_FILES_PUBLIC
must be changed
with an
ALTER
SYSTEM
command. Double quotes around the parameter name are mandatory,
since it starts with an underscore (
_
).
SQL> ALTER SYSTEM SET "_trace_files_public" = TRUE SCOPE=SPFILE;
Double quotes around the parameter are not required when a text parameter file (
PFILE
) is
used. Since the parameter is static, the instance must be shut down and restarted for the new
setting to take effect. Using
ORADEBUG
(see Chapter 37) we can quickly verify that read permis-
sion for others is now granted on newly created trace files.
SQL> ORADEBUG SETMYPID
Statement processed.
SQL> ALTER SESSION SET SQL_TRACE=TRUE;
Session altered.
SQL> SELECT sysdate FROM dual;
SYSDATE
---------
25-JUL-07
SQL> ORADEBUG TRACEFILE_NAME
/opt/oracle/obase/admin/TEN/udump/ten1_ora_18067.trc
SQL> !cd /opt/oracle/obase/admin/TEN/udump;ls -l ten1_ora_18067.trc
-rw-r--r-- 1 oracle oinstall 1241 Jul 25 20:53 ten1_ora_18067.trc
As you would expect by looking at the parameter name,
_TRACE_FILES_PUBLIC
has no effect
on permissions of the alert log.
ASM Test Environment and
_ASM_ALLOW_ONLY_RAW_DISKS
Automatic Storage Management (ASM) is essentially a volume manager and a file system for
exclusive use by ORACLE instances. The volume management capabilities include mirroring
and striping. ASM implements the S.A.M.E. (stripe and mirror everything)
2
approach. ASM uses a
number of raw devices,
3
concatenates them into a large pool of storage, and offers the storage
space as a kind of file system to ORACLE instances. Raw disks (e.g., LUNs in a SAN) are grouped
into disk groups. ASM can rely on RAID storage arrays for mirroring (external redundancy) or it
can do its own mirroring (normal/high redundancy). If necessary, disks in a disk group may
The format in which the UNIX command
ls
displays permissions, is {r|-}{w|-}{x|-}. This sequence of
characters is repeated three times. The left part applies to the owner of the file, group permissions are
in the middle, and permissions for anyone (a.k.a. world) are on the right. A minus sign means that the
permission represented by the position in the string is not granted. For example,
rwxr-xr-x
means that
the owner may read, write, and execute, the group may read and execute and anyone may read and
execute.
1.
2.
Oracle10
g
Release 2 on Linux supports block devices too. These are opened with
O_DIRECT
to eliminate
caching by the Linux operating system kernel as with raw devices. Performance is the same as that of
raw devices, which have been deprecated on the Linux platform.
3.
