Another question on a seemingly simple “not exists” query has appeared on OTN just a few days after my last post about the construct. There are two little differences between the actual form of the two queries that make it worth repeating the analysis.
The first query was of the form:
select from big_table where not exists (select exact_matching_row from small table);
while the new query is of the form:
select from big_table alias1 where (more...)
This one is quick and short. I have been asked few time, how can we check what value was specified to OSDBA, OSOPER and OSASM,especially during upgrades (to know what was it set to which initial installation)
# The DBA_GROUP is the OS group which is to be granted OSDBA privileges.
# The OPER_GROUP is the OS group which is to be granted OSOPER privileges.
# The OSASM_GROUP is the OS group which is to (more...)
Advanced Oracle Troubleshooting Guide – Part 12: control file parallel reads causing enq: SQ – contention waits?
Vishal Desai systematically troubleshooted an interesting case where the initial symptoms of the problem showed a spike of enq: SQ – contention waits, but he dug deeper – and found the root cause to be quite different. He followed the blockers of waiting sessions manually to reach the root cause – and also used my @ash/ash_wait_chains.sql and @ash/event_hist.sql scripts to extract the same information more conveniently (note that he had modified the scripts to (more...)
Oracle Midlands Event #9 is now confirmed with another great lineup!
Thanks to Red Stack Technology for sponsoring the event, allowing it to remain free!
Put the date in your diary. See you there!
Oracle Midlands : Event #9 was first posted on April 24, 2015 at 10:32 am.
©2012 "The ORACLE-BASE Blog". Use of this feed is for personal non-commercial use only. If you are not reading this article in your (more...)
Overnight I got an auto-upgrade to WordPress 4.1.3 maintenance release and a notice telling me WordPress 4.2 “Powell” was released. The downloads are in the usual places, and of course available from the update screen in your blog.
The announcement page has a video explaining the new features, which seem to make it easier to repost other people’s content, where you would normally expect to just tweet a link. Not sure what (more...)
Little things worth knowing: Is there a penalty in establishing a connection to Oracle using the MAA connection string? Part 2
In the very lengthy previous post about the MAA connect string I wanted to explain the use of the MAA connection string as promoted by Oracle. I deliberately kept the first part simple: both primary and standby cluster were up, and although the database was operating in the primary role on what I called standby cluster (again it’s probably not a good idea to include the intended role in the infrastructure names) there was no (more...)
I’ve just been motivated to resurrect a couple of articles I wrote for DBAZine about 12 years ago on the topic of bitmap indexes. All three links point to Word 97 documents which I posted on my old website in September 2003. Despite their age they’re still surprisingly good.
I’m trying to compare how a query runs on two different 22.214.171.124 systems. One runs on HP-UX Itanium and one runs on 64 bit x86 Linux. Same query, same plan, different hash value.
SQL_ID 0kkhhb2w93cx0 -------------------- update seg$ set type#=:4,blocks=:5,extents=:6,minexts=:7,maxexts=:8,exts ize=:9,extpct=:10,user#=:11,iniexts=:12,lists=decode(:13, 65535, NULL, :13),groups=decode(:14, 65535, NULL, :14), cachehint=:15, hwmincr=:16, spare1=DECODE(:17,0,NULL,:17),scanhint=:18, bitmapranges=:19 where ts#=:1 and file#=:2 and block#=:3 Plan hash value: 1283625304 ---------------------------------------------------------------------------------------- | Id | Operation | Name | Rows | Bytes (more...)
We are discussing the management of Oracle Database 12c in Oracle Enterprise Manager 12c. In our previous blog post on this topic, we looked at how the Self-Service console would appear to the Self-Service Application (SSA) user, with the ability to provision databases, schemas or PDBs on the fly.
We are discussing the management of Oracle Database 12c in Oracle Enterprise Manager 12c. In our previous blog post on this topic, we looked at “Database as a Service” and “Schema-as-a-Service”, and also talked about “Pluggable database (PDB) as a Service (PDBaaS)”.
Today I worked on silent upgrade of Oracle GoldenGate from 126.96.36.199.0 to 188.8.131.52.2, so thought to blog it which might help some of you. These are the steps I performed
Current GoldenGate Home –> /oracle/app/product/ogg12.1.2
1. Gather the details of GoldenGate Processes before stopping them
GGSCI> INFO EXTRACT EXTL, SHOWCH INFO EXTRACT DPUMP, SHOWCH GGSCI> SEND EXTRACT EXTL, SHOWTRANS GGSCI> STOP EXTRACT DPUMP GGSCI> STOP (more...)
A common issue I’ve noted are dump files generated from the AWR Warehouse, but upon failure to transfer, the dumpfiles simply exist, never upload and the data is stuck in a “limbo” state between the source database, (target) and the AWR Warehouse. This can be a very difficult issue to troubleshoot, as no errors are seen in the actual AWR Warehouse “View Errors” and no data from the source is present in the AWR Warehouse.
Take a look at these two items from a form I was using today.
If, like me, you thought that checking those boxes meant you agreed with the statements, you would be wrong. It turns out what they mean is you’ve remembered to copy that text into the main body of your request. WTF?
I suggested to the company in question, they either make the check boxes work as they should, or at least change (more...)
WordPress 4.1.2 has been released. It’s a security release and I’m guessing most of you will pick it up passively using the auto-update features, so it’s nothing to worry about too much.
You can read about the fixes in this release here.
I’ve just installed it on 5 separate installations and there were no dramas.
WordPress 4.1.2 was first posted on April 21, 2015 at 5:02 pm.
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I’ve been blogging now for almost 6 years and presenting at conferences for… 12 years (really? Good grief!). I’ve even written and delivered several courses, ranging from 1 day to 3 days in length. However, up until now I’ve never been what I would term published – ie managed to persuade another organisation or person to publish something I have written.
That changed a few days ago when the latest UKOUG “Oracle Scene” magazine (more...)