Performance question - Separating fast changing attributes into separate dimensions
hi,
i'm trying speed ad hoc cube browsing in excel 2007. have periodic snapshot fact table with mainly last child measures. fact table has about 1.8 million rows. main dimension holds account information, and has 40,000 rows. capture change scd type 2 approach.
to speed ad hoc cube browsing in excel, should separate fast changing attributes in dimension table, provided they're not queried, separate dimension table? have 6000 distinct accounts, , the 'status' attribute forcing new row.
this is how a chopped down version of dimaccount table looks currently, showing 'loantype' attribute, doesn't change, , 'status' attribute, changes frequently:
dimaccountkey accountreference status loantype startdate enddate
123 1234567 payments utd regulated 20111010 20111131
124 1234567 initial arrears stage regulated 20111201 20120222
125 1234567 second arrears stage regulated 20120223 20790606
my thinking if put fast changing status attribute own dimension table, should reduce size of dimaccount table (i may be able get close 6000 rows for 6000 accounts). should performance.
thanks in advance,
adam
hi adam,
i this:
create 2 partitions start of with. 1 currentdate , other before current(today's) date. (make sure set "slice" properties both partitions).
create aggregations on both partitions using wizard giving 30% performance gain create the initial draft. (check query perfomance after this, if you're satisfied can stop @ step. )if not ...
enable query log , run sort of possible queries might think used tune cube using usage based optimization(ubo)
download bids helper codeplex if haven't yet. 1 of great thing tool is, allows add aggregations query log table w/o dropping existing aggregations created first aggregation wizard.
you have decent idea on how users query cube. based on : review these aggregations query log , see if can adjust attribute levels described before ("day->month->year") impact query pattern. creating affective aggregations sort of art have understand business , query pattern of users. won't @ first, you'll come of set of aggregations that'll satisfy user queries.
hope give ideas.
rok
please remember mark answered if post helped resolve issue.
SQL Server > SQL Server Analysis Services
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