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Quick tip–database link passwords

If you are relying on database links in your application, think carefully about how you want to manage the accounts that you connect with, in particular, when it comes to password expiry.

With a standard connect request to the database, if your password is going to expire soon, you will get some feedback on this:



SQL> conn demo/demo@np12
ERROR:
ORA-28002: the password will expire within 6 days


Connected.


But when using those same credentials via a database link, you will not get any warning, so when that password expires…you might be dead in the water.

In Memoriam – 2

This is the second of two items that my mother typed out more than 25 years ago. I had very mixed emotions when reading it but ultimately I felt that it was a reminder that, despite all the nasty incidents and stupid behaviour hyped up by the press and news outlets, people and organisations are generally kinder, gentler and more understanding than they were 60 years ago.

This story is about the birth of my brother who was born with a genetic flaw now known as Trisomy 21 though formerly known as Down’s syndrome or (colloquially, and no longer acceptably) mongolism. It is the latter term that my mother uses as it was the common term at the time of birth and at the time she typed her story.

12.2 New Feature: the FLEX ASM disk group part 3

In the previous 2 parts of this mini series I introduced the Flex ASM disk group and two related concepts, the Quota Group and File Group. In what should have become the final part (but isn’t) I am interested in checking whether quotas are enforced.

(Un)fortunately I have uncovered a few more things that are worth investigating and blogging about, which is why a) this isn’t the last post and b) it got a bit shorter than the previous two. Had I combined part 3 and 4 it would have been too long for sure … BTW, you can navigate all posts using the links at the very bottom of the page.

Are quotas enforced?

The purpose of the Quota Group is … to enforce quotas on a disk group, much like on a file system. This is quite interesting, because you now have a hard limit to which databases can grow within a disk group even for non-CDBs.

In Memoriam

My mother died a few weeks ago after a couple of months in terminal care. One of my tasks while she was in care was to go through all her paperwork and while doing so I discovered a couple of stories from her past that she had typed out (remember type-writers?) about 30 years ago. I typed them up on my laptop and printed several copies to hand out for people to read at the tea-party we held for her old friends – of all ages, ranging from 15 to 99 – after the funeral; this seemed to give them a lot of pleasure and they found them so interesting that I decided to share them with a larger audience. So here’s the story, written by my mother in 1983, of her evacuation experience at the start of the 2nd world war when she was a little over 14 years old.

AskTOM TV episode 8

On AskTOM episode 8, I’ve taken a look at locating the SQL Plan Directives used for a particular query.  Here is the script output from the video if you want to use this for your own exploration

Top Ten Travel hints and Tips

Well, let me be honest right at the top here.  These are not travel hints Smile  These will not help you in any way.

This is me having a whine and a rant about a minority of people that I occasionally encounter when travelling.

Yes, this can probably be best described as me and my first world problems, but I need to expunge these so that next time I travel, I don’t lose my head, and stuff some poor unsuspecting innocent passenger“under the seat in front of me or in the overhead locker” Smile

DIY parallel task execution

We had a question on AskTOM recently, where a poster wanted to rebuild all of the indexes in his schema that had a status of UNUSABLE.  Running the rebuild’s in serial fashion (one after the other) seemed an inefficient use of the server horsepower, and rebuilding each index with a PARALLEL clause also was not particularly beneficial because the issue was more about the volume of indexes rather than the size of each index.

An obvious solution was to use the DBMS_PARALLEL_EXECUTE facility.  Our poster was pleased with our response but then came back asking for help, because they were stuck languishing on an old release for which DBMS_PARALLEL_EXECUTE was not yet present.

It’s just bad code or bad design … most of the time

Some years ago I wrote an article for the UKOUG magazine called “Want a faster database – Take a drive on the M25”.  For those not familiar with the United Kingdom, the M25 is one of its busiest roads (M = “motorway”) and because it moves so much traffic, and runs so close to capacity, it has often been referred to as “the world’s largest car park”.  Many people have probably spent a good part of their lives on the M25 Smile  I used the M25 as a metaphor for how database professionals can focus on the wrong things when trying to solve a performance problem, such as:

“I’m stuck in traffic…perhaps a faster car will help”

ie, throwing CPU at a problem that is not CPU bound will not help things, or

“I’m stuck in traffic…it must be the width of the paint on the lane markings”

Index compression–quick tip

If you’re appropriately licensed and want to use advanced index compression, you can take advantage of the setting a tablespace to automatically add compression as a default at a nominated level in the database.  From the docs:

Here is an example of that in action.   We’ll set our tablespace default accordingly


SQL> create tablespace demo
  2  datafile 'C:\ORACLE\ORADATA\DB122\DEMO.DBF'
  3  size 100M
  4  default index compress advanced high;

Tablespace created.

Now we’ll create a table and an index on it in that tablespace

OTN Yathra 2017

The amazing 6 city set of events is just around the corner, with all of the dates and details available at http://otnyathra.in/

image

Here are my thoughts on why you should be attending