Inspecting work area usage for memory is an important aspect of my job when I’m performing a tuning exercise. This is especially true when we are talking about specific processes vs. overall database level. Often, along with SQL enhancements, choices in source objects to a process can improve performance drastically. Most developers are focused on the results of query, especially with tight deadlines vs. performance and the DBA can often assist them in succeeding with both. The process for our example today is a CTAS, (create table as select) that has a number of joins , a union, along with…
-
-
So I tried to finish out some of my OOW posts, but I ended up talking about this with a friend and thought I would share how I became Facebook friends with Larry Ellison instead…. After returning from Oracle Open World 2011, I sat one day at my desk, staring in disbelief, (as many Oracle folks busy in the social media world during OOW were that day) at a friend request from Larry Ellison’s Facebook account. I accepted it and me and my fellow DBAs then reviewed the account to verify that this was Larry’s official account and yes, he’d…
-
Great day today with a second WIT session and all the interviews and General Session for Enterprise Manager 12c. If you are looking for the ebook, you can download it from Oracle here. A couple people caught on that I was tweeting while discussing the benefits of EM12c, even capturing me in a photo, (will never live it down… :)) They played the trailer for the new Cloud Odyssey movie Oracle has been working on to promote EM12c and cloud. It’s been a lot of fun as they’ve talked about how they came up with the idea based off the…
-
The ACE Director briefings are done and now we are onto Sunday sessions. I’ve already had a couple meetings with folks today and wondering why I didn’t wear flats at 2pm in the afternoon, but there are the important necessities that must be taken care of, like when am I speaking this week, so here’s the schedule: My Oracle Open World Schedule My Oak Table Schedule If you want to meet up to chat, best to hit me up on Twitter @DBAKevlar and loving Oracle Open World 2013 already!
-
This is Part IV in a multi-part series, demonstrating how to take EM12c from out of the box to enterprise level. You can read Part I, Part II, Part III and Part IV to complete the first phases of this setup and look for future posts in this series to ensure your EM12c is set up to support your database world. Tracking Warnings through the Incident Manager There were a few changes we made to metrics so that we have moved generic alert log alerts to “warning” only. We now need to add one rule to create incidents so these are logged in the…
-
This is my last WIT post on the challenges on women in the workplace. The truth of the matter is, its just too difficult to write about what women are facing in the workplace without a large amount of risk. Someone is going to view your posts on what you or someone else has experienced in the workplace as a liability or as disparaging because so often the reader sees the experience through their own eyes and not that of the writer. That’s just the way of the world and I’ve got to do right by my family first, so I’ll…
-
This is Part IV in a multi-part series, demonstrating how to take EM12c from out of the box to enterprise level. You can read Part I, Part II and Part III to complete the first phases of this setup and look for future posts in this series to ensure your EM12c is set up to support your database world. Incident Rule Sets There was a slight mis-communication between development groups when the Incident rules and the metric value settings were configured for the EM12c “out of the box”. Currently, 90% of metrics are only set with warning thresholds. The Incident rule sets…
-
… in any one instance the effects of [] stereotypes may be quite small- if you don’t get credit in one meeting, that’s not exactly disastrous, but over time, a little bit here and little bit there, these bias can add up and this can carry men and women into very different directions in their careers. This statement, made by Shelley Correll, Professor of Sociology at Stanford University, Director of the Michelle R. Clayman Institute for Gender Research, as part of a Lean in web education video, resonated with me as I have recognized this often in my own career and noticed…
-
Oracle OEM 12c introduces a new feature that enables the creation of Oracle database thin clones by leveraging file system snapshot technologies from either ZFS or Netapp. The OEM adds a graphic interface to the process of making database thin clones. The feature that enables database thin cloning in OEM is called Snap Clone and is part of OEM’s Cloud Control Self Service for data cloning. Snap Clone is available via the feature Database as a Service (DBaaS). Snap clone leverages the copy on write technologies available in some storage systems for database cloning. Support is initially available for NAS…
-
Here are the tuning metrics tables (SQL stats are not in “metric” tables per say) (*DBA_HIST_…_HISTORY views are sort of confusing. AFAI remember they were storing alert history, but apparently they are used for adaptive thresholds – an area for future investigation) I’ve noticed a number of people posting queries using DBA_HIST_SYSSTAT instead of DBA_HIST_SYSMETRIC_SUMMARY which leads me to believe that there is some confusion or lack of information on the metric tables. Oracle 10g introduced metric tables which compute deltas and rates of statistics thus hugely simplifying the ability to answer simple questions like “what is the I/O rate on my…
-
Here is a quick table comparison of different types of metrics views The first line of the table is the classic wait event and statistic views. The following lines are the metric views. The metric views were introduced in Oracle 10g. Why Metrics are good Metric views compute deltas and rates which hugely simplifying the ability to answer simple questions like “what is the I/O rate on my databases right now?” This question, before 10g, was surprisingly tedious to answer. To answer the question one would have to query v$sysstat for example: Select value from v$sysstat where name=’physical reads’; but…
-
I’ve had a couple peers ask me about this recently- They’ve attempted to discover targets on a host and experienced failures. This commonly occurs for the following reasons: 1. Incorrect information regarding the target exists at the target host level. 2. The OMS has an unresolved issue, status in pending state, etc. My recommendation on #2 is to always check each step as your implement EM12c, (complete the EM12c installation, adding a new host, adding a new database, etc.) Your status should be 100% green, if its not, take care of this first before you start attempting to add…
-
Many of you know that I’m the mother of three, very bright, “equally ADHD as their mother” children. As I’ve been tasked with a number of interesting challenges with both RMOUG’s and ODTUG’s WIT, (Women in Technology) events, I’ve started to investigate how, no matter what we do for women today, unless we start focusing on the women of tomorrow, we are lost. I spent some time the last couple weeks investigating the offerings by my local school districts for technical education and am alarmed for both genders. There are “Technology Plan Templates” that detail out the dismal specifications of…
-
A male peer of mine approached me just after Collaborate and discussed this incredible woman in the Oracle community that he was trying to promote and inspire. I had met her at a couple sessions and agreed- I was impressed with her knowledge, energy and intelligence as well and he asked if I would assist in promoting her- I was thrilled and agreed. I promptly contacted her via Linked in and I sent her an invite. She just accepted my Linked in request this month and it really had me thinking- It wasn’t like she hadn’t been on Linked in,…
-
This is Part III in a multi-part series, demonstrating how to take EM12c from out of the box to enterprise level. You can read Part I and Part II to complete the first phases of this setup and look for future posts in this series to ensure your EM12c is set up to support your database world. Monitoring Templates Monitoring templates, when created via an example database and then used as the default for all databases, allows the DBA control to create incidents and notify on what metrics are important to the business. Creating a Template As templates are…
-
If one is seeing waits for enq: TX – row lock contention then there could be a lot of reasons. One distinguishing factor is the lock mode. If the lock mode is exclusive (mode 6) then it’s most likely a classic row lock where two sessions are trying to modify the same row. On the other hand if the lock mode is share (mode 4) it’s typically going to be Primary/Unique Key: inserting a unique key when someone else has already inserted that key but not committed Foreign Key: Inserting a foreign when then parent value has been inserted but not…
-
One thing that I have found sorely missing in the performance pages of Enterprise Manager is latency values for various types of I/O. The performance page or top activity may show high I/O waits but it won’t indicated if the latency of I/O is unusually high or not. Thus I put together a shell script that shows latency for the main I/O waits db file sequential read db file scattered read log file parallel write direct path reads direct path reads temp Of course it would be nice to add a few others like direct path writes, direct path writes…
-
Anyone who has been around Oracle performance over the years knows the grief that hard parsing SQL queries can cause on highly concurrent applications. The number one reason for hard parsing has been applications that don’t use bind variables. Without bind variables queries that would otherwise be shared get recompiled because their text is different and Oracle treats them as different queries. Oracle addressed this issue with a parameter called cursor_sharing. The parameter cursor_sharing has three values exact – the default similar – replace literals with bind variables, if a histogram keep literal in place force – replace literals with…