The Blogger Newbie Quest

I’ve decided it’s probably a good thing that blogspot doesn’t show the *exact* time I publish my posts… 🙂  I rarely write or publish anything before 10pm at night and have been saddened as I’ve become aware, (as I am a perfectionist at heart…) that I’ve made a couple mistakes in my blog.  My ADD brain …

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When PGA Size is Not Enough

I’ve come to realize that most folks don’t really understand the limitations in the allocation of PGA memory to hashing and sorting. They truly believe that if they set their PGA high enough, the database will just allocate as much memory as they have in the setting towards any hash or sort process, when in …

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ERROR-400|Data will be rejected for upload from agent ‘https://:/emd/main/’, max size limit for direct load exceeded in OEM

After a lovely week off, I came back into work and brought up the OEM console to take a quick look at our databases. I noticed all our databases from one server were set to timing out on their uploads of the agent to grid control in the “All Targets” View. I logged onto the …

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The Good, the Bad and The Ugly

Two weeks ago, after a new mart had performed excellent for 24hrs, a sudden and detrimental decline in performance was seen. I’d been trying to track this issue for almost two months, but had only seen it in two or three processes total and never to this level. I had some history from previous DBA’s, …

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ORA-14097: column type or size mismatch in ALTER TABLE EXCHANGE PARTITION

A developer needed to do some serious data changes to a partition. I thought I’d be a helpful DBA and suggested he do a CTAS of the one partition, make the change and we’d exchange the partition. He was thrilled when the update statement that I’d killed after 24 hrs of no successful runs was …

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The Makings of a Great DBA Team

As I’ve spent two “tours of duty” as a Lead DBA in my career, I often keep in mind what makes a great DBA team, noting both when companies realize what it takes and when they don’t. I’ve watched great DBA’s walk out the door because during the interview process someone decided the candidate didn’t …

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ORA-01427: single-row subquery returns more than one row

A developer friend of mine sent me an email today frustrated that none of the DBA’s he worked with could explain this error to him and sent it onto me. I thought I would get a post out with this one as I think it trips up a lot of folks: “I have a report …

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Utilizing Separate Temp Tablespace

The Challenge: You want one process in your application to use a separate temp tablespace created on faster “ram disks” even though it executes the same packages on the same objects as the other applications. The complication in the challenge is that TEMP is not like other resources such as default tablespace. Even though you …

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Rebuilding Vs. No Rebuild on Indexes

This is a subject that I see a lot of debate on, but as a DBA who works in mostly large data warehouse and mart environments, I am a pro-rebuild DBA. Many of the large systems I work on are home-grown and designed. This means that there is either design or code issues that lend …

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Presenting at RMOUG 2010!!

So I’ve been accepted to present at the 2010 RMOUG Conference and I am understandably nervous. This is my first large presentation I’ve given and I’m thrilled to be doing it. My topic is the power of parallel processing, something I’ve been working heavily in as of late and I feel I have a lot …

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Why Isn’t Oracle Allocating More Parallel Slaves?

You have a statement that somebody, without thinking about resources, requested 96 total parallel processes for. They have now come to you, the DBA and want to know why, they aren’t getting the parallel they have requested: The statement starts out something like this: create table table_too_large_data tablespace mart_data1 compress nologging pctfree 0 parallel 16 …

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Gathering Statistics on Highly Partitioned Tables

method_opt=>’for all columns size 1′ This is the method option for DBMS_STATS.GATHER_TABLE_STATS that is commonly recommended- “Let Oracle look at all the columns and decide what kind of statistics, histograms, etc. need to be gathered on each…” I’ve never been real thrilled about it, especially in a data warehouse or mart environment where we rarely …

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