Nice X-Window emulator

On Windows, at-least, once in a while DBAs need to remotely access the UNIX/Linux GUI tools such as OUI, DBCA etc from putty or an SSH client.   Tools like Exceed are very expensive and VNC port forwarding is a bit of complex solution (also you need vnc software).  

To overcome this, you can try this tiny little software called Xming.  The setup file is only about 2MB of size and very easy to install.  All you need to do is to start the Xming, open a putty session and check “Enable X11 Forwarding” option under SSH->X11.   Log into the Linux/Unix sever and straight away you can test it by running xlogo/xclock.  No need to even set the DISPLAY env variable.  Very nice indeed.

I just tried it and it is absolutely working fine .

Standby v$archived_log

It happened last week, that one of my colleague came to me in a hurry and said that the archived logs are not getting applied on standby (Oracle 10gR1).  When I went and checked the standby database, everything was OK.  It applied till the last archived log.  On the primary database side though, the status was ‘NO’ for few of the archive logs

Standby:

SQL> SELECT SEQUENCE#, ARCHIVED, APPLIED FROM V$ARCHIVED_LOG WHERE SEQUENCE# > 11210 ORDER BY SEQUENCE#;

SEQUENCE# DEST_ID ARC APP
———- ———- —
11211 YES YES
11212 YES YES
11213 YES YES
11214 YES YES
11215 YES YES
11216 YES YES
11217 YES YES
11218 YES YES
11219 YES YES

Primary:

SQL> SELECT SEQUENCE#, ARCHIVED, APPLIED FROM V$ARCHIVED_LOG WHERE DEST_ID = 2 AND SEQUENCE# > 11210 ORDER BY SEQUENCE#;

SEQUENCE# DEST_ID ARC APP
———- ———- —
11211  YES YES
11212  YES YES
11213  YES NO
11214  YES YES
11215  YES NO
11216  YES YES
11217  YES YES
11218  YES NO
11219  YES YES

 I did a search on metalink and came across this document ‘Note:263994.1‘.  This is what mentioned as cause :

“The cause of the problem is that the APPLIED column of V$ARCHIVED_LOG on the primary is not always updated. If the sequence number you look at was actually sent as a GAP (could not be sent originally and was later sent by an ARCH process as part of a FAL request).

In such a case the APPLIED column for that sequence number will not be updated. “

The conclusion is that, we cannot fully trust the v$archived_log on primary server.