What do you do?

Fortunately, you still have a chance of saving your job.

1. Logon as root

2. Create a new directory anywhere that you prefer to use as swap fs. I prefer creating under the root directory and name it as /swapfs

mkdir /swapfs

3. We will create a data dump of a bunch of zeroes and store it in a X-bytes worth of file. The X-bytes will represent the size of swap file that you want or need. What is the ideal size? My answer has always been, it depends! If its just your PC for browsing the internet etc…, same size with your RAM will do. If its a database server, you may not want to use swap intensively, so blow up your RAM instead. I typically benchmark it from half of my RAM, to even twice my RAM. Again, it depends on what type application is running on your server or PC.

dd if=/dev/zero of=/swapfs/swap bs=1M count=4096

I am creating here a 1 megabyte swap file. It will create a file named swap under the directory /swapfs

4. I’ll now assign /swapfs/swap file as a SWAP space

mkswap /swapfs/swap

5. Of course, that is not enough, you have to enable it

swapon /swapfs/swap

If you’ll issue a df command, you’d be able to see the new swap filesystem, and the top command will also display the additional swap space.


select wait_class, sum(total_waits), sum(time_waited), round(sum(time_waited)/sum(total_waits),2) WAIT_TIME_PER_TXN
from V$SERVICE_WAIT_CLASS
where service_name='RECONPRD' group by wait_class
order by sum(time_waited)/sum(total_waits) desc

This would immediately tell me how much time is spent (or “wasted”) on any DB component.

As a DBA, it would be of interest to me to maintain wait classes that are high on Administrative, Configuration, Concurrency. I would definitely hit the programmers when it comes Application-related wait events, and the System Administrators for Disk I/O related wait times.

1. Administrative – Commands issued by a privileged user (that is, DBA) that result in other users waiting—an index rebuild, for example.
2. Application  – Generally related to application design, this category includes lock waits caused by row-level locking and explicit or implicit lock commands (implicit lock commands such as those generated by a DDL statement).
3. Cluster  Global cache, global enqueue, and global messaging – related wait events in a RAC environment.
4. Commit -  Currently only includes a wait event for redo log sync confirmation after a commit.
5. Concurrency -  Generally, waits involving concurrent parsing and buffer cache latch and lock contention; indicative of many sessions going after the same resources.
6. Configuration -  Wait events in this category can generally be resolved by tuning; includes undersized log buffer space, logfile sizes, buffer cache size, shared pool size, ITL allocation, HW enqueue contention, ST enqueue contention, and so on.
7. Idle  Session is inactive.
8. Other  – Catchall for wait events not associated with one of the predefined classes.
9. Network  – Waits for data to be sent over the network—specifically waits in the networking layer or on hardware.
10. Scheduler -  Waits due to Resource Manager prioritization.
11. System I/O  – Waits on I/O done by background processes (except for MMON and SMON).
12. User I/O -  Wait for blocks to be read off disk by foreground process, SMON, or MMON.

References:

Oracle-Dox.Net

After canceling the creation, we can no longer use the server, and that we had to to do a db2_kill. We had to reboot the server, restart DB2 via Db2start. The other databases will start  after  a successful crash recovery, but the last one, where we created the BP, would then trigger the memory and paging space usage high again.

this is when we discovered that since crash recovery makes use of archive logs to recover, it tries to redo the create bufferpool, thus we cannot start the database. Fortunately, we found a site on IBM specifically  dealing with this case.

We had to stop DB2, and issue a

db2iupdt -w 32 <instance name>

This converts the instance to 32-bit mode, which is immune to this case of irregular size of buffer pool. You can now startup  db2 normally. To move forward the archive log recovery, we had to run a backup, for the database to recognize a new set of archive logs and not to read the old logs with the create BP statement. After the backup, we reverted back to 64-bit mode by issuing

db2iupdt -w 64 <instance name>

We were then able to recover the Database with no damage data.

Grotto @ Boracay

I’m referring to incidental costs (e.g. repairs on top of the regular maintenance costs), because we can always budget or prepare for the maintenance costs (operating expenses)

Anyone?

Stupid SPSS

Try adding up the values on the Frequency field and see if it matches the total

alter table mytable move compress;

Compression depends on the cardinality of data per field on your table. The more that a value repeats itself on a field, the higher the compression is. As i understand it, the algorithm is highly similar with how compression works on Winzip and Gzip.

On one of my produciton tables, I was able to achieve almost 10x compression (a 9.2GB table was compressed to 1GB).

Compression comes at a price though, Read-write will be penalized as the application has to decompress the table prior to writing.

To resolve this, save the job on a text file and save it as .sas file.

Trigger your job by using the ff command

!SASROOT/sas -sysin yourprogram.sas -noterminal