A database system optimised for reporting, particularly in aggregate. Often, but not always implemented using a star schema.

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41 views

Dimension or Degenerate Dimension?

I am taking a course on data warehousing. Currently, I am reading through Ralph Kimball's Data Warehouse Toolkit. I understand that a degenerate dimension is a dimension key that is stored in a fact ...
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2answers
124 views

Daily snapshot fact table

I have a list of products per costumer. Costumers can delete or add products to their list. I want to know in each day what is the list of products (and count) by costumer. My first approach is to ...
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1answer
215 views

Should I snowflake or duplicate it across my facts?

I'm building up a data warehouse to be used by SSAS to create cubes on, and I'm debating between two possible schemas. In my warehouse, I've got two different fact tables that tracking daily changes ...
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1answer
54 views

Migrate Management Data Warehouse to a New Instance

Is there a defined procedure to follow for moving a SQL Server 2012 management data warehouse to a new server\instance? We intend to setup an MDW on a test sql server instance first, but will then ...
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1answer
300 views

creating a report on the mysql jasperReport server

I have mysql local database, in it I have sample data mart. I have installed jasperReport server to my computer. Just using this tool, I want connect to the local mysql database and just create a pdf ...
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1answer
56 views

Database design suggestions for a data scraping/warehouse application?

I'm looking into the database design for a data warehouse kind of project which involves a large number of inserts daily. The data archives will be further used to generate reports. I will have a ...
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1answer
39 views

Constellation Schema; Relationships between fact tables

What are acceptable types of depedendcies between facts in a multiple-fact schema? Conceptually talking, As you know a Multi-Dimensional Model may have multiple facts (like in a constellation ...
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180 views

Updating a big replicated Dimension (SQL Server PDW)

We use a SQL Server PDW appliance for our data warehouse. One of the tables in our warehouse is a replicated table with about 20 million rows. As part of our ETL process we need to expire old records ...
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148 views

Geographic Hierarchies in a OLAP Cube / Data Warehouse

Are the following geographic hierarchies correct? Do any US/Canadian area codes cross state/province lines? Do any US/Canadian counties cross state/province lines? Are there countries with counties ...
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117 views

How to gracefully handle a source database restore from backup in a data warehouse

We are facing a challenging situation with our data warehouse source databases. Frequently these sources databases will be restored from backups. There is a high turnover of data entry persons who ...
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45 views

500GB Data Warehouse - how to split it into FileGroups?

OK, so I have: 500 GB DW 5 GB in smaller DBs 220 GB TempDB 350 GB in Log files. My machine is Fujitsu Primergy 64 cores (with HT) and 192 GB RAM. I have several IO locations: 540 GB in-server ...
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0answers
67 views

What type of fact table / loading solution for a reservation system?

I am designing a Data Warehouse with SQL Server 2012 and SSIS. The source system handles hotel reservations. The reservations are split between two tables, header and header line item. The ...
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32 views

Monoblock, Multiblock queries?

What exactly mean the terms monoblock / multiblock queries in data warehouses when talking about materialized views? Does a monoblock query just use one data source (a normal table) while a multiblock ...
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13 views

Should I use conventional or computed columns for trivial metrics in a fact table?

A fact table can often have measures which are basically trivial. For example Orders.NumOrders will probably be "1" for every real record (synthetic records representing "no order" may populate this ...
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0answers
15 views

Does data guard support Oracle Warehouse Builder?

Does data guard support Oracle Warehouse Builder (both 11.2.0.4)? If not, what is the procedure to setup/configure my OWB project (repository, workspace, control center service...) on the standby ...
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0answers
15 views

When there is a Type 1 and type 2 SCD in a dimension table, how are updates to the type 1 column handled after the type 2 column is updated?

Eg: ID Type1SCD Type2SCD FromDate todate 1000 100 ABC 01-JUL-2014 NULL Now, Type2SCD is updated ID Type1SCD Type2SCD FromDate todate 1000 100 ABC 01-JUL-2014 12-JUL-2014 ...
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73 views

Is there better way to design SQL tables

I need to design a quick application for small warehouse. I just want to check if there is a better design approach. I am using polymorphic associations for comments tables. Business Rules If ...
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0answers
50 views

Running materialized view refresh in parallel

I have a large materialized view that is refreshed periodically (complete refresh) and I would like to do it in parallel. I can already run the query part in parallel but the problem is (much slower) ...
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82 views

MySQL: Error 1118 using create table select and barracuda file format

We want to create the equivalent of some materialized views in a read-only slave for really performant reporting. The queries used to generate these tables span 19 tables with a fair number of ...
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80 views

How much RAM do I need?

Let's assume a query like the following as typical: select A.`date` as `date`, count(*) as N from A as A join B as B on B.id = A.b_id join C as C on C.id = B.c_id join D as D on D.id = ...