Comments on: Getting MOLAP Storage Working with OWB10gR2 http://www.rittmanmead.com/2006/10/19/getting-molap-storage-working-with-owb10gr2/ Delivered Intelligence Wed, 17 Mar 2010 13:47:41 -0400 http://wordpress.org/?v=2.8.4 hourly 1 By: Raymond de Vries http://www.rittmanmead.com/2006/10/19/getting-molap-storage-working-with-owb10gr2/comment-page-1/#comment-1570 Raymond de Vries Wed, 05 Sep 2007 13:18:26 +0000 http://www.rittmanmead.com/wp2/2006/10/19/getting-molap-storage-working-with-owb10gr2/#comment-1570 There is a performance problem when craeting the MOLAP via OWB. I recently had a performance problem with my MOLAP loading and after many hours with Oracle OLAP support (Germany) we were able to identify the problem area. It seams that OWB creates a different type of AW to what AWM creates. I first created dimensions and cubes with OWB, result slow load. Then with AWM I deleted the dimensions and cube from the OWB created AW and recreated the dimension and cube, result slow load. I then created a new AW with AWM and then created the dimensions and cube, result fast load. In all cases I used the same sparcity settings. I should have tried creating the dimensions and cube with OWB but using the AWM created AW. I am not sure if the problem has been resolved in 11i OWB version, I still need to test it. The OLAP support desk could not explain the reason but stated that the OLAP development team gets the new rekleases of OLAP long before the OWB development team in the US. They think that this could be the reason. There is a performance problem when craeting the MOLAP via OWB. I recently had a performance problem with my MOLAP loading and after many hours with Oracle OLAP support (Germany) we were able to identify the problem area. It seams that OWB creates a different type of AW to what AWM creates. I first created dimensions and cubes with OWB, result slow load. Then with AWM I deleted the dimensions and cube from the OWB created AW and recreated the dimension and cube, result slow load. I then created a new AW with AWM and then created the dimensions and cube, result fast load. In all cases I used the same sparcity settings. I should have tried creating the dimensions and cube with OWB but using the AWM created AW. I am not sure if the problem has been resolved in 11i OWB version, I still need to test it. The OLAP support desk could not explain the reason but stated that the OLAP development team gets the new rekleases of OLAP long before the OWB development team in the US. They think that this could be the reason.

]]> By: Mark Rittman » Back Home, and Reflections on Open World http://www.rittmanmead.com/2006/10/19/getting-molap-storage-working-with-owb10gr2/comment-page-1/#comment-1569 Mark Rittman » Back Home, and Reflections on Open World Sun, 29 Oct 2006 14:24:00 +0000 http://www.rittmanmead.com/wp2/2006/10/19/getting-molap-storage-working-with-owb10gr2/#comment-1569 […] I’m actually in the UK for the next few weeks, and mostly working from home/the local office apart from two days running the BI Masterclass at Oracle City Office, London. I’m quite looking forward to this one - a bit like taking a tour around the world, then playing at home at the end - and as usual I’ll be adding a bit more content, this time around the slight difference in dimension and cube creation in OWB when you’re working against a multi-dimensional dataset. The seminar in the UK actually sold out a few weeks ago, and Oracle are therefore running a second event on November 23rd/24th which you can still book up for. Once the seminar is done, I’m preparing a one-day course for one of our University clients on building effective data warehouses using Oracle 10g, delivering it and then getting things sorted out for the UKOUG Conference in Birmingham the week after. The good thing is that this all means I’ll be UK-based for a few weeks, but it’s going to be a busy time and all very client-focused. […] […] I’m actually in the UK for the next few weeks, and mostly working from home/the local office apart from two days running the BI Masterclass at Oracle City Office, London. I’m quite looking forward to this one – a bit like taking a tour around the world, then playing at home at the end – and as usual I’ll be adding a bit more content, this time around the slight difference in dimension and cube creation in OWB when you’re working against a multi-dimensional dataset. The seminar in the UK actually sold out a few weeks ago, and Oracle are therefore running a second event on November 23rd/24th which you can still book up for. Once the seminar is done, I’m preparing a one-day course for one of our University clients on building effective data warehouses using Oracle 10g, delivering it and then getting things sorted out for the UKOUG Conference in Birmingham the week after. The good thing is that this all means I’ll be UK-based for a few weeks, but it’s going to be a busy time and all very client-focused. […]

]]> By: mark http://www.rittmanmead.com/2006/10/19/getting-molap-storage-working-with-owb10gr2/comment-page-1/#comment-1568 mark Mon, 23 Oct 2006 01:44:00 +0000 http://www.rittmanmead.com/wp2/2006/10/19/getting-molap-storage-working-with-owb10gr2/#comment-1568 Osvaldo - I think you can just go into the data object editor, remove the ID column, rename the other columns and redeploy the dimension; you shouldn’t need to recreate it from scratch, or redeploy the measures. The redundant ID column is just an attribute, it’s not the long or short description, or the dimension member ID. Pete - you can select which standard calendar level (year, quarter, month, year) or fiscal calendar level you want using the wizard, or as you say you can go into the dimension definition, after the wizard has run, to add your own attributes. Again, as you say, you’d need to create your own custom load mapping, but I do that anyway, so it’s not really an issue. Osvaldo – I think you can just go into the data object editor, remove the ID column, rename the other columns and redeploy the dimension; you shouldn’t need to recreate it from scratch, or redeploy the measures. The redundant ID column is just an attribute, it’s not the long or short description, or the dimension member ID.
Pete – you can select which standard calendar level (year, quarter, month, year) or fiscal calendar level you want using the wizard, or as you say you can go into the dimension definition, after the wizard has run, to add your own attributes. Again, as you say, you’d need to create your own custom load mapping, but I do that anyway, so it’s not really an issue.

]]> By: Pete_s http://www.rittmanmead.com/2006/10/19/getting-molap-storage-working-with-owb10gr2/comment-page-1/#comment-1567 Pete_s Sun, 22 Oct 2006 08:53:00 +0000 http://www.rittmanmead.com/wp2/2006/10/19/getting-molap-storage-working-with-owb10gr2/#comment-1567 Mark, does the time table function allow you to edit custom calendars? - I know many business with strange year lengths for reporting - year must always stat on a Sunday, some years are 53 weeks (I even seen a 57 week year!) Start dates can be useful if your “month” always starts on a Monday. Can you not just use the time wizzard to creat the dimesnion object then throw away the supporting mappings and edit what’s left? Mark, does the time table function allow you to edit custom calendars? – I know many business with strange year lengths for reporting – year must always stat on a Sunday, some years are 53 weeks (I even seen a 57 week year!)
Start dates can be useful if your “month” always starts on a Monday.
Can you not just use the time wizzard to creat the dimesnion object then throw away the supporting mappings and edit what’s left?

]]> By: Osvaldo Santos http://www.rittmanmead.com/2006/10/19/getting-molap-storage-working-with-owb10gr2/comment-page-1/#comment-1566 Osvaldo Santos Thu, 19 Oct 2006 18:06:00 +0000 http://www.rittmanmead.com/wp2/2006/10/19/getting-molap-storage-working-with-owb10gr2/#comment-1566 Hi, It’s good to finally find some information on OWB and MOLAP storage. You see, being a newbe to DW+BI I left the ID column, in addition to the business key and description columns, on all my objects, since everywhere I read said that this was the minimum requirement for the dimension, not mentioning that different rules apply for MOLAP, OWB documentation included. Now, I have created a lot of dimensions and all where created following the “standard” way: ID + Business key + Desc, what if I wanted to switch to the model you just exposed? Would this affect all my cubes? Best regards, –Osvaldo [osantos] Hi,
It’s good to finally find some information on OWB and MOLAP storage. You see, being a newbe to DW+BI I left the ID column, in addition to the business key and description columns, on all my objects, since everywhere I read said that this was the minimum requirement for the dimension, not mentioning that different rules apply for MOLAP, OWB documentation included.
Now, I have created a lot of dimensions and all where created following the “standard” way: ID + Business key + Desc, what if I wanted to switch to the model you just exposed? Would this affect all my cubes?
Best regards,
–Osvaldo
[osantos]

]]>