I’ve been working with OBIEE for a while now, but I’ve not actually gone through the Oracle By Example tutorials, so I figured it would be a good idea to do that. I started looking at the first Oracle By Example OBIEE tutorial yesterday and came across an issue with a simple solution to share [...]
Archive of posts tagged DW
No pruning for MIN/MAX of partition key column
Recently, I wanted to work out the maximum value of a column on a partitioned table. The column I wanted the maximum value for, happened to be the (single and only) partition key column. The table in question was range partitioned on this single key column, into monthly partitions for 2009, with data in all [...]
TPC-H Query 20 and optimizer_dynamic_sampling
I was working with Jason Garforth today on creating a TPC-H benchmark script which we can run on our warehouse to initially get a baseline of performance, and then, from time to time, rerun it to ensure things are still running with a comparable performance level. This activity was on our new warehouse platform of [...]
Scripts for loading up DBGEN TPC-H data
If you’re interested in creating a TPC-H schema for testing purposes, then the following scripts may be of use to you: Unix Scripts:Multi Load TPCHLoad TPCH Stream SQL*Loader Control files:REGION TableNATION TableSUPPLIER TableCUSTOMER TablePART TablePARTSUPP TableORDERS TableLINEITEM Table You may wish to read and check them before you use them – they’re not exactly rocket [...]
Oracle Optimized Warehouse Initiative (OWI)
I enjoyed a trip out of the office today with my manager. We went down to the Oracle Enterprise Technology Centre, in Reading, to hear about the Oracle Optimized Warehouse Initiative. It was basically a half day pitch from Oracle and Sun today, although there are other dates with different hardware vendors (IBM, HP and [...]
Is ASSM evil in a DW?
I saw an interesting article on ASSM from Howard the other day. I wanted to comment on it but unless I’m being a bit thick, it doesn’t seem to be a blogpost and therefore I couldn’t and instead, I thought I’d do it here. As I said, I found the article interesting and informative but [...]
Good to be back in the 21st Century…and identifying PEL mismatches
Well, I can honestly say, that moving house over the last few months has been an experience I don’t wish to repeat for a good few years – if not decades! I’ve only just got my broadband enabled for the new place – hence my first post in ages – and that was a miracle [...]
Partition exchange loading and column transposing issue
I came across an interesting issue yesterday whereby a partition exchange load routine wasn’t working for my colleague Jon. The ensuing investigation seems to point at the possibility of a bug, whereby after exchanging a partition Oracle may have inadvertently transposed columns in the target table. I’ve created a test script to illustrate the problem [...]
TRUNCATE command marks previously UNUSABLE indexes as USABLE
Yes, I’m back…but on an adhoc basis as I still don’t have enough time for this really! Yeah – I know, you’re all in the same boat I came across this problem on the warehouse the other day and was slightly surprised by what was going on… We have an OWB mapping which does a [...]
RAC and data warehouses – Are they compatible ?
I watched one of the presentations of the Audio CD from UKOUG Conference 2005 – Getting the most of of RAC on Linux by James Anthony and was interested to see his comments that reducing the block size / reducing the rows per block can help in tuning the interconnect between the instances of a [...]