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As I continue to work on very large databases, (VLDB), I am exposed to more opportunities to speed up IO. This can involve Oracle’s solution of Exadata or stand alone improvements with options such as SSD, (Solid State Disk) which can offer faster IO performance at a fraction of the price. When this option becomes a reality, there will always be non-DBA’s that advise what would best benefit from the hardware, but to take the time to research what would truly benefit is important for the DBA to perform. The Just the Facts on Solid State Disk: There are several…
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As part of an 11g Upgrade, it was found that a database environment could be built from one of the upgraded databases through a duplicate. As this process had never been performed before in this fashion, a test was in order. The test was an excellent chance to discover that the OSUser that performs the duplicate process was the proud owner of a .kshrc file with hard coded Oracle variables set which was an excellent choice if you want to really screw up a new duplicate database… 🙂 Scenario: 1. Duplicate has started with correct variables set. 2. Subsequent shell…
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As many know I’ve been busy trying to bring our many-times patched 10g Enterprise Manager migrated to a new server with EM12c. I thought it would be interesting to see how fast I could break it, considering my skills, I knew it might not be a challenge. Scenario 1. Bug with listener refusing to connect dynamically to EM12c repository database. 2. After releasing code to the database for advanced notification, the SYSMAN.MGMT_ADMIN_DATA package has gone invalid, which is used to manage much of the repository at the command line. 3. The repository owner password has become corrupted. These were my…
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I had worked hard on a report, 47 SQL statements in all to tune it down from 5 hrs to under 30 minutes. The first runs had been quite successful, so when a third run sent an alert on temp usage, I knew something was wrong. SID PROCESS MACHINE SQL_TEXT SQL_ID TOTAL MB -------- ------------ -------------------- --------------------- 507 1137 HOST SELECT *** 7t3muww36xhzn 45516 600 1139 HOST SELECT *** 7t3muww36xhzn 45516 525 1132 HOST SELECT *** 7t3muww36xhzn 45516 509 1135 HOST SELECT *** 7t3muww36xhzn 45516 I checked the stats first, as one of the fixes was to ensure the staging…
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Oracle Open World is over for me now, but what a great event it was. I met so many people and actually was able to spend a little time getting to know a few of them. I attended parties, dinners and meetups. I networked myself, my company and RMOUG. It was a phenomenal turn out, even with a few folks missing that I knew we’d miss terribly Arriving- California Zephyr If you hadn’t heard, we decided to take a train from Denver, CO to San Francisco, CA. via Amtrak, called the California Zephyr. This was a 33 hour train ride,…
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Yes, typing on my tablet screen again, so patience with my short posts…:-) Had the pleasure of attending both the ACE and Oak table dinners the last two nights. Wonderful, impressive and technically gifted people at every table and a fantastic opportunity to meet so many that I’ve only known virtually. I enjoyed another set of high energy conversations with Gwen Shapira, Debra Lilley, Robyn Sands and Lisa Dobsen- all women who make me proud of the representatives of my gender in the technical world. Spent sometime with Mark Bobak, Kent G., Alex G., Craig S., Jeremy Schneider, Mike Swing…
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After a long first day and a 33 hr train ride in, I’m ready for a fun and enjoyable Ace dinner that I’m a lucky guest to. First day, being Sunday, is commonly quiet, but Tim had two sessions that I wanted to attend and time flew by with meetups, expert panels, etc. I met a number of great new people today and saw some more old friends, (or as “new blood”, can I refer to them as old?) I was still recovering after a fantastic get-together at Graham Woods from lastnight. I was impressed with the great group of…
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Rarely are reports based off large snapshot variances helpful to a DBA unless you come across an odd situation such as this one…Better yet, we need to know a little bit about our AWR tables behind our reports so we can piece together what the reports leave out…:) Scenario: After-hours support has killed a session after high temp usage has occurred. You, as the primary DBA, are left to look into the issue the next day. Your first attempt to inspect the issue is through Enterprise Manager, (OEM) and you are surprised that very little activity is actually showing up…
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I’ve spent the week updating, packing and communicating in preparation for my trip to Oracle Open World 2011. As with most folks that are attending, there is a lot to prepare for, but I have that added challenge of three kids who find this a fine opportunity to drive their father to distraction, as my ex-husband is responsible with managing their week, which he is unaccustomed to. Although I’m thankful for Google calendar that will tell my ex where and when each child has to be at all times, what homework, social events, etc., it is not a lot of fun for…
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Users complained that a monthly financial report would no longer run SQLServer Reporting Services, (SSRS.) Upon investigation, it was found that this was a stored procedure that ran from one Annex database, sourcing from another and outer joins to a SQLServer database on a remote server through a linked server configuration. In attempts to run the report, my SQL Server Profile traces on both the source SQL Server and the remote SQLServer resulted in consistent sp_reset_connection results from the source and no activity in the remote. I ran my trusty and favorite script to tell me what processes were…
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“Oh what tangled web we weave when complexity is added we can’t see…” How many times has complexity of design in an application, outside of the database, lead to the database blamed for slow performance? This is where a manager thanks the technical Gods for a DBA with great Sherlock Holmes skills to track down and prove the database not only innocent, but figure out what the real problem is. The database is guilty until proven innocent, we all know that, so when user’s come to the DBA and demands, “Why can’t I run this report? I should be able…
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If you desire a subject that will invoke deep passion and often combined with disgust from a group of DBA’s, disaster recovery is the one. It is the subject that rarely we feel our butts are not out there hanging, no matter how much we’ve attempted to secure our environment. I’ve observed a consistent flow of articles, conversation and email discussions on the subject and it is apparent that rarely is the business as aware as the technical specialists, (aka the DBA) of just how vulnerable their environments are. Rarely are the budget dollars allotted to the task of insuring…
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I truly believe that database myths are the scourge of the database world. With that said, I have to blame myself for not being specific enough in one of my own blog posts and propagating one myself! As it was brought to my attention by Tanel Poder and Greg Rahn, I hadn’t put a post out here until now, so apologies! I have flipped back to an almost exclusively 10g environment the last three months, but even though I’m back to my old stomping grounds, now fully staffed with almost double the DBA’s that were present when I left, have…
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This is another blog post about how TEMP can kill you in performance. The Program Global Area, aka PGA, is a memory region that allows Oracle to perform many processes that once fell to static calculations in parameters that had to be managed by a DBA. As frustrating as it might be to a DBA to not have enough memory to allocate to the performance enhancing feature, I found it even more frustrating to find NO PGA allocation to window sorts. We were experiencing poor performance in one of our environments, but I noted it was only during heavy workloads,…
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The introduction of the temp tablespace was a crucial step in the RDBMS to separating the “work area” for sorting and specific join operations from permanent segments. To eliminate the performance challenges of sorts and hash against the I/O threshold involved with performing this word in the temp tablespace, Oracle 9i introduced the Program Global Area, (PGA) to complete sorts and hashes within memory. DBA’s spent considerable time tuning the PGA, attempting to continually ensure that as more complex sorting and join features emerged, that these processes would complete their work within the PGA and not require such a large…
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A blog post by Simon Cooper sent up a reminder of a subject that has been at the forefront of my mind for the last couple weeks and is a follow up to my blog post The Superman Conundrum. I’d had lunch with a previous coworker from years ago about less than stellar management behavior directed towards him as an employee and also spoke last week to another previous co-worker about challenges in her current workplace. I’m pretty content with how I am treated at my company. Even though the company does not comprise of techies, they at least attempt to…
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This is when I know I’ve been doing too much database work in one day. I awoke from a dream, quite early in the morning and was replaying it in my head. The scenario went like this: Scene: City streets, obviously a murder scene with yellow tape drawn and bystanders watching off to the sides as the main characters, two seasoned detectives are discussing the decision to enter the crime scene. Officer #1: “Are we sure we covered our bases? Is there anyway the criminal could have escaped the scene or we could have compromised the evidence when we entered…
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