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

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Data Warehouse - Slowly Changing Dimensions with Many to Many Relationships

As an example, let's say I have a fact table with two dimensions and one measure FactMoney table ProjectKey int PersonKey int CashAmount money The two dimensions are defined like this: ...
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4answers
251 views

SQL Server: Database integration and synchronization

I have n SQL Server databases with the same data schema. On the other hand i have a web application that needs to retrieve, for some entities, the union of the information stored into the n ...
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644 views

Handling time zones in data mart/warehouse

We are starting to design the building blocks of a data mart/warehouse and we need to be able to support all time zones (our clients are from all over the world). From reading discussions online (and ...
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145 views

Query to return fields of distinct values per key

In the process of building a data warehouse we are creating some aggregation tables for a reporting engine. We would like to build a single aggregation table from the fact table that can exist as list ...
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4answers
992 views

best ETL design to transfer transaction tables records into the data-warehouse

I have 2 type of tables to populate the data-warehouse with every day, lookup tables or configuration tables with few 100s records, and thats easy where i just truncate and refill the table. but for ...
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1answer
349 views

What database and setup can handle several million inserts per minute? [closed]

We have come to a point where for a few of our customers' systems, at peak times, events are generated at that crazy rate. That is, millions of new events per minute (between 1M and 2M). The ...
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3answers
586 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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161 views

how to being building a data warehouse [closed]

We have a ERP system that uses a DB in postgres, each table has many rows and we want to build data warehouse (data warehousing). Also we want to add BI using ETL where would begin? would use schemes ...
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158 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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121 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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333 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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268 views

Where and how to store my weird datamart

I could really use some help here. Here's my situation. I'm building a datamart in SQL Server 2005, which will furnish a single report (for now). We have 26 clients (medical organizations) that ...
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2answers
861 views

Can a surrogate key and a primary key be in the same table?

For example we have: Surrogate key: ABC123 Primary key: 1 Name: James Is this legit in a Data Warehouse table?
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3k views

SSIS convert DT_WSTR to date

I'm new to SSIS trying to covert data types. I'm pulling data from Google Analytics and loading data into a SQL 2008 database. The date column from Google analytics appears as "DT_WSTR" and the values ...
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1answer
238 views

How to handle “many columns” in OLAP RDBMS

I have a fact that has around 1K different numerical attributes (i.e. columns). I would like to store this in to a column-oriented DB and perform cube analysis on it. I tried to design a star ...
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2answers
180 views

Teradata performance statistics

I need some statistics regarding the performance of Teradata, something like with a given hardware, given nodes and given AMPs - a table which has thousands of rows can be read in 't' secs. I need ...
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491 views

Header and line item data source mismatch

I'm working with a star schema for a data warehouse and I am running into a problem with header and line items from different data sources. CREATE TABLE DataSourceAHeader ( OrderId INT NOT NULL ...
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497 views

sql server 2008 execution plan different on two production servers [closed]

We have two servers running SQL server 2008 R2, with identical databases, where we implemented a datawarehousing solution. The cube processing operation was taking a VERY long time in one of the ...
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1k views

Is SQL Server data compression categorically good for read-only databases?

Some literature on SQL Server data compression I read state that the write cost increases to about four times what would normally be required. It also seems to imply that this is the primary downside ...
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228 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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363 views

Modeling staff dimension in data warehouse

I need to write a data warehouse diagram. I've got a problem with staff area. I have to store a information about workers details like name, age etc., and workers job time and agreement details like ...
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247 views

Open source tools to manage Data Quality [closed]

Are there open source (or commercial) tools that can report data quality issues in a data warehouse using the Kimball star schema model? It doesn't have to be the silver bullet. I'm just looking for ...
3
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1answer
94 views

What to do with duplicate lookup information

I have multiple databases that I want to store in one data warehouse database. I am wondering how I design the import process to handle multiple lookup tables. For example, say I have 5 databases all ...
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1answer
197 views

Conceptual Design of a data warehouse (declaring the grain)

I am trying to design a data warehouse using this example scrubbed data. I need to declare the "grain". I know its the lowest level of detail in the fact table, but I am having a hard time determining ...
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2answers
166 views

Disaster recovery plan - Having multiple servers

I work in an organization where departments are in different buildings. I have a data centre in the main building. All the in-house applications connect to the SQL Server residing in the server in the ...
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1answer
212 views

Is there a standard way to replace codes with values from a lookup table for reporting or analytics?

Suppose I have a "main" table that was probably heavily normalized and consists largely of columns that merely contain codes that are lookups into other tables (they are probably foreign keys but feel ...
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489 views

Data warehouse support tickets

I'm starting to design a data warehouse for a company. The first questions we're trying to resolve are regarding their support ticketing system. My initial schema is as follows Now one of the ...
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482 views

Big Data vs Relational Database on making structure of Data-ware house for telecom data analysis [closed]

I'm currently doing my final year project on telecommunication mining. On starting project I got confuse on choosing database. As data on mobile communication is going on increasing so I think Big ...
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256 views

What are good resources on data modelling for business intelligence? [closed]

We are a SaaS startup offering purchase & procurement solutions. The data model for operational transactions has been created (relational DB). We also want to offer analytics on those transactions ...
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2answers
212 views

XML Large DataBase is the best? [closed]

Is the best way to implement a large database is XML? Or is there a better way? 1 - reduce the time complexity 2 - Reduce the amount of traffic between the tables And other factors ... Which ...
5
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2answers
3k views

ETL: extracting from 200 tables - SSIS data flow or custom T-SQL?

Based on my analysis, a complete dimensional model for our data warehouse will require extraction from over 200 source tables. Some of these tables will be extracted as part of an incremental load and ...
5
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2answers
904 views

Cardinality rule for bitmap indexes

The Oracle documentation includes the following advice: A bitmap index should be built on each of the foreign key columns of the fact table or tables In that reference, there is even a bitmap ...
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326 views

Force chain to start immediately after completion instead of on a timer

Is it possible to force an Oracle chain to restart immediately after it finishes executing, instead of on a timer? I have only found ways to do a temporal restart, which doesn't really work for me as ...
5
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3answers
2k views

Partition pruning with multiple date columns

I have a large table in Oracle 11g database that holds historical data from several years, so I would like to partition it by year. The problem is that the table has multiple date columns and they are ...
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210 views

how often to run Tablediff

I wonder if it is safe to run the Tablediff tool on a database fairly often? Let's say every 15 or 30 minutes. Also, the Data in the DB is around 100 GB.
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140 views

Advices for modeling facts, time hierarchies based on two conditions

Sorry if my question does not belong to that SE but I tried to find the best place and it ended up here. My problem is this : I've got a table modeled as this in our datawarehouse env. : MYTABLE ...
5
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1answer
317 views

When should startup parameter -E be used?

We are starting to build a data warehouse system using SQL Server 2008 R2. One of the senior DBAs told us to consider using a startup parameter -E for the SQL Server service. I read from Books Online ...
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2answers
517 views

Isolation Level for a Data Warehouse

We are building out a data warehouse (and also some data marts as well) in our organization. My DBA skills have mostly been on OLTP type applications, but I am moving into supporting OLAP for our ...
2
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1answer
1k views

In star schemas, what should I do when a dimension has a date attribute?

I'm trying to learn about dimensional models and star schemas. Say I have a Sales fact table recording the total sales at retail stores, with, say, four dimensions, Date, Customers, Stores, and ...
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43 views

Oracle scheduler chain priority in data warehouse applications

The scenario is as follows: We have a data warehouse type application that relies on the Oracle job scheduler and a Chain. This chain is responsible for generating materialized views (caches) that ...
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301 views

SQL Server 2005 replication for a data warehouse

We are trying to implement some kind of Data Warehouse at my current employer. Most of our data is in a SQL Server 2005, but we might also integrate some Access databases and some databases in a SQL ...
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1answer
361 views

How to represent aggregates in a data warehouse

I am building the dimensional model for a data warehouse (as an exercise for a mini-course I am doing) and I want to build an aggregate to speed up queries. Basically, I want the aggregate to group ...
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1answer
381 views

Should I Link a Fact to Hierarchical Dimension at ALL Levels or only the most granular?

Related question about the same project here. I'm looking at two approaches to model a hierarchical relationship between my fact and dimension tables in a data warehouse for storing IT infrastructure ...
8
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1answer
173 views

Dimension and Fact for same entities?

I'm rather new at DW design and am working on a DW to model some IT infrastructure. The major problem/question at this point is how to model drive information. We will be collecting aggregate data ...
2
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1answer
836 views

Does surrogate key assignment for a fact table require that the source data has natural keys?

Let's say I have a simple OLTP database with orders, products, and customers: And from it, I am building a data mart with an orders fact table, product dimension, customer dimension, and date ...
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215 views

How to simplify schema for multi database / hundreds of millions of rows data set

We currently have a MySQL data set that was started about 10 years ago that aggregates a log of data, and accumulates millions of rows each month. The people that developed our system started ...
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3answers
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How do you roll up header-level values on a fact table with line-item granularity?

From what I've read, the recommended granularity for a fact table based on an order header / line item structure is at the line item level. In the process, any additive values that apply only to the ...
3
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1answer
106 views

Architectural Question about Data analytics

I understand that in many OLTP architectures there is some ELT stuff which creates a OLAP Data warehouse model and then you can run data analytics on this. However, this can take some time to ...
3
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1answer
133 views

Reporting Table Design

I'm writing a system that allows users to store values against each week in October and November and each day in December - starting from the first Monday. I'm holding the raw data entered by the ...
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505 views

SQL Server 2012 Data Warehousing Overall Flow [closed]

I am studying Data Warehousing in SQL Server 2012 I am attempting to learn the various tools included by practicing on the different tools separately. I have practiced with: AdventureWorks ...