A few weeks ago I wrote a post about log parallelism causing excessive log file sync waits. Ever since, I’m finding more and more examples how this bug affects OLTP and hybrid databases (and even some data warehouses)! For example, my current employer is a large organization that has several thousand databases (set up at different time by different teams), and according to the studies I conducted on a sample of a few dozen databases, (more...)
I found a broken link to an Oracle help document in one of my posts and when I went to the Oracle 12c database documentation to find the new URL to put in my post I found that Oracle had totally revamped their online manuals.
Here is a link to the new high level Oracle help site: url
I’ve only looked at it for a few minutes and can’t say whether I like it or (more...)
The NoCOUG fall conference featuring Toad University will be held at the eBay Town Hall in San Jose, CA on Wednesday, November 19. If you have never attended a NoCOUG conference in the 28-year history of NoCOUG—yes, that’s how long NoCOUG has been around—you’re invited to attend the upcoming conference for free. Simply send your name, title, and company to firstname.lastname@example.org.
Toad Overview and Roadmap for DBAs, Developers, and Data Analysts—Daniel Norwood & (more...)
An interesting case of ORA-600 :)
I was paged for standby lag and started looking into the issue. The db version was 220.127.116.11.0 version. Standby was lagging behind by 36 archives
SQL> @mrp INST_ID PROCESS STATUS THREAD# SEQUENCE# BLOCK# DELAY_MINS ---------- --------- ------------ ---------- ---------- ---------- ---------- 1 MRP0 WAIT_FOR_LOG 1 568330 0 0 INST_ID PROCESS STATUS THREAD# SEQUENCE# BLOCK# DELAY_MINS ---------- --------- ------------ ---------- ---------- ---------- ---------- 1 RFS IDLE (more...)
Every so often our competitors like to spread false information about our solutions so as to gain unfair advantage. I wanted to address this for the Enterprise Manager Snap Clone functionality, so this blog post describes the Snap Clone solution as it currently stands (November 2014).
Yesterday I attended #cluboracle event in London (I highly recommend this event! ... but I don't recommend Thameslink train service :) ). In this event one interesting discussion popped up regarding 12c. I've already written about this feature, so in this post I'll clarify some points as I understand them and test out a few more things.
Here is a quote from my last post summing up my findings so far:
This new column seems (more...)
It’s recommended to use latest plugins with EM12c (to minimize bugs, better support for new releases of target etc), and you probably set notifications to get mails about plugin updates, but sometimes you just ignore them because you don’t have time. So you may want to check if any plugins you use have updates. It’s possible to do it using EM12c web interface. All you need is to go to “self update” page, click on (more...)
I am back from AIOUG meet “SANGAM 14 – Meeting of Minds” and it was a wonderful experience. Had really nice time meeting some old friends and making few new ones :). I think i should mention here, finally i met Amit Bansal , mind behind http://askdba.org/ . It was fun meeting him :)
It was 3 day conference with
1st day :- Optimizer Master Class by Tom Kyte. It was full day seminar. Learned (more...)
As I write, there’s an ongoing thread on Oracle-L that started with the (paraphrased) question: “I’ve got this query that returns 7 million rows; when I change it to ‘select count(*)’ it returns in 4 seconds but when we display the full result set on screen it takes hours, and every second or two the screen pauses; how do I make it go faster.”
The general rapid response was: “You shouldn’t be running 7M rows to a screen (more...)
I’m surprised to find that Google is not cleanly ranking the helpful set of blog posts by Oracle’s Maria Colgan on the Oracle Database 12c In-Memory Column Store feature so I thought I’d put together this convenient set of links. Google search seems to only return a few of them in random order.
Over time I may add other helpful links regarding Oracle’s new, exciting caching technology.
I suppose it had to happen eventually but one of my presentations has ended up on YouTube. It’s a recent presentation I did for the Oracle Midlands user group in September.
The topic is (as the title of this blog post hints at!)Boosting select performance by clustering data. The video consists of the slides I presented, changing as the presentation progresses, with my audio over the top. It goes on for a bit, (more...)
There are a large number of “moving parts” when performance tuning or trouble shooting an Enterprise Manager environment. The new EM performance features, (available in release 18.104.22.168) are there to assist you in understanding the source of the issue and can really make the difference for those that are unfamiliar with the challenges of Weblogic, java, network or other complexities that make up EM12c and aren’t commonly thought of as part (more...)
As I help a peer with a SQL Tuning engagement, I face the frequent case of: “We do not want to gather CBO schema object statistics because we don’t want our Execution Plans to change”. Well, the bad news is that: not gathering stats only gives you a false sense of safety because your Execution Plans can change anyways. The reason has to do with Predicates referencing values out of range. Typical cases include range (more...)
In most of the environments, one set of OGG processes (1 Extract & 1 Replicat process) is sufficient for change data synchronization. But if your source database generates a huge volume of data then a single process may not be sufficient to handle the data volume. In such a scenario there may be need to […]
The post GoldenGate not keeping up? Use GoldenGate Range function to split up the process appeared first on VitalSoftTech.
Is Oracle Database 12c (22.214.171.124.0) Faster Than Previous Releases?
I was wondering if the new Oracle Database 12c version 126.96.36.199.0 in-memory column store feature
will SLOW performance when it is NOT being used. I think this is a fair question because most Oracle Database systems will NOT be using this feature.
While the new in-memory column store feature is significant, with each new Oracle feature there is (more...)