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Questions tagged [olap]

On-Line Analytical Processing, a class of systems designed for fast calculation, reporting and analysis of aggregate figures.

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15 views

Is there such a thing as an OLAP cube that can change the number of levels in a hierarchy without having to be rebuilt?

The current analytics solution that my team works with cannot handle changes in the structure of one of its hierarchies. If a new level or branch is added, then the entire domain must be first backed ...
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25 views

NoSQL database for analytics

Need NoSQL database for analytics. Given: Large, partitioned Postgres(9.4) tables, with next structure: - device_id: UUID - monitored_date: TIMESTAMP - properties: jsonb (different keys) (...
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14 views

Are OLAP / NoSql / In-Memory database mutually exclusive concepts or can there be overlap between them?

I'm a data scientist with little knowledge of DB technology. I keep hearing 3 types of databases mentioned as key technologies for analytics and modeling solutions: NoSql databases OLAP cubes In-...
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Building a data cube in a data warehouse through Inmon architecture?

I have been reading about data cubes and Kimball. Through building a star schema, one can then model a cube using its measures and dimensions of the star schema. But then there is a different data ...
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1answer
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What exactly is the 'online' in OLAP and OLTP?

I'm a bit confused because I'm questioning the definition of 'online' in OLTP and OLAP. I used to think that 'online' here means that we want our answer in bounded time and based on the data available ...
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133 views

Where to build the OLAP cubes? [closed]

I have built a data warehouse with multiple fact tables and dimension tables (with a MySQL server). Now where could I build the OLAP cubes and write the MDX queries to produce results? BTW, I have ...
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1answer
54 views

SQL to MDX translation?

An MDX (a language dealing with multidimensional data, in particularly dealing with the cube metaphor) statement can be translated to an SQL (a well-known language for the relational model) statement -...
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0answers
334 views

connection to remote Analysis Services from SSMS

On my company local SQL Server instance I was able to add a linked server to a remote AS instance (in Management Studio > Server Objects). I was also able to connect using Data Tools, as well with ...
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2answers
656 views

Cons of using a star schema in a columnar database

My organisation is implementing a new data warehouse using a columnar data store (Redshift) and the performance is currently abysmal. There are many causes for this but I think the key reason is ...
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0answers
105 views

Proactive caching vs. nightly cube reprocess

I'm working with an SSAS cube that's fully reprocessed every night by an SSIS job. My current goal is to get data into the cube with less latency, and to do so I'm looking at implementing proactive ...
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169 views

Process an OLAP Cube as a daily job takes too long using `ProcessFull` option

I have two cubes which updates in sequence. These takes very long to update, upwards of 5 hours due to their sizes. I have a SQL agent job which updates the cubes. The job has type SQL Server ...
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1answer
18 views

Using OLAP-specs to compute selective running totals

Let's say I have a table with columns id, subid, state, value, where (id, subid) is a unique tuple, state may be 0 or some value <> 0, and value is just some number. I want to build a query that ...
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1answer
233 views

OLAP window functions in DB2

I am using DB2 z/OS 11.1.5. According to this reference, OLAP functions such as first_value should be supported at least in DB2 9.7. However, when trying to execute the query declare global ...
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2answers
617 views

Dealing with different types in a fact table

I'm working with dimensional modelling for the first time, trying to build a data warehouse that pulls in data from an OLTP database, and I'm having some trouble figuring out what to do with this type ...
2
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1answer
654 views

SSAS Realtime Processing

I created a cube in SSAS, how I can extract real time data from the data source to my cube? I mean if any data modification (insert, update, delete) happens, SSAS should update the cube.
3
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1answer
542 views

Why do OLAP cubes perform better than Relational databases on certain tasks?

My team uses a Multidimensional OLAP database for a lot of it's analytics and predictive modeling. The standard line in all the documentation is "OLAP cubes are better suited for this type of ...
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1answer
63 views

MAT over a calculated measure [closed]

We have an OLAP SSAS cube with budget data on the fact table, and budget cathegory (sales, costs, salaries, ...) on a dimension. We have a bunch of formulas for our users but we are not able to create ...
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0answers
206 views

Reduce RAM required to process OLAP cube

I have a cube which I have created by using (in Visual studio) New Project -> Import from Server (Multidimensional and data mining). This cube is indeed created from the metadata of an already ...
6
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1answer
834 views

SSAS OLAP Semi-Additive Measure over Time Dimension

Issue: Help, I'm relatively new to building OLAP cubes in Microsoft's SQL Server Analysis Services and I need help with a semi-additive measure over a time dimension. In other words, I want to show ...
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0answers
40 views

What schema if I have many measures

Forgive me if I misuse any words. I'm a c++ programmer with some basic DB knowledge. I'm developing an analytics engine for simulation data for vehicle engines. OLAP seems like a good fit but I haven'...
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3answers
858 views

Should dates in dimensional tables use dimDate?

Assuming my dimDate has a surrogate key. Should all the date columns in the dimensional tables (not the fact tables) store the surrogate key of date dimension? Or just plain date? For example, in ...
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1answer
934 views

speed up PostgreSQL calculations via OLAP warehouse?

So I have asked these three questions: Percentile rank that takes sorted argument (or same functionality) in PostgreSQL 9.3.5 https://quant.stackexchange.com/questions/29572/building-financial-data-...
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0answers
60 views

Incorrect hierarchy relationship while joining with parent-child tables

I have two tables with 1:M relation in my DB: GROUP (GroupId, GroupName, AccountId) USER (UserId, UserName, GroupId, AccountId) and ACCOUNT (AccountId, AccountName). I added all needed links from ...
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1answer
114 views

Is OLAP cube duplication of data?

Is an OLAP cube a duplication of data or is it just references to original tables? Or can I control it?
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1answer
209 views

SQL Server connection, session, command handling

I am trying to build an etl tool that tracks DMV data from SSAS Instance. To do that and in advance to record sql queries that users are request, i must know how the sql server handles the connection, ...
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1answer
401 views

SSAS Cache Levels

I am using SSAS for reporting statistics on a big amount of data. Recently I began learning best practices for tuning and I am interesting in how SSAS caches the data. I have done my research and I'...
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1answer
199 views

pglogical for OLAP queries

I am looking to setup a replica for OLAP queries. Currently in my prod I have a master (OLTP node) replicating to a slave via streaming replica. I don't want to use streaming replica for OLAP queries ...
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3answers
1k views

SSAS How to calculate Standard Deviation

I'm trying to calculate a variety of statistical calculation across a range of data such as Standard Deviation and Average. The data comes from many different "Data sources". These are are held in a ...
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1answer
31 views

Should I put OLAP and realtime web DBs on the same server?

I have several different workloads I'd like to consolidate into the same Sql 2012/2014 instance. Cognos/OLAP is burst oriented and users are accustomed to a response delay Web databases that require ...
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0answers
110 views

SSAS 2014, Relation OLAP - Poor performance, high resource usage, what did I do wrong?

Let me start with the background, I was working on a project that needed a back end that was scalable and fast. Having worked quite a bit with SSAS, I thought I'd try SSAS's in memory solution, ...
3
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1answer
2k views

Star Schema from Relational Database

I'm a newbie to data warehousing and I've been reading articles and watching videos on the principles but I'm a bit confused as to how I would take the design below and convert it into a star schema. ...
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1answer
157 views

OLTP to OLAP process causing deadlocks and impacting customers

I should preface this with the fact that I'm a .net developer who has fallen into DBA and performance work because it has become business critical, so I'm missing the DBA skills for this kind of work. ...
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2answers
2k views

SSAS where are olap cubes stored

Getting started on creating data cubes with SSAS. I understand the various types of OLAP options ROLAP, HOLAP and MOLAP. However, when creating a data cube using SSAS (at least for 2008 version) I do ...
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1answer
86 views

SQL Server Table Design for Report - Is OLAP Schema Suitable

A work colleague is developing SQL Server database tables for a reporting project. Basically, the only activity on the table will be populating it from a ETL process (SSIS). He insists on creating a ...
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0answers
196 views

Is it possible to use Hibernate for OLAP-server?

I have a PostgreSQL database with Java Hibernate. I need a XMLA datasource for a pivot grid client component. Is it possible to use Hibernate for a OLAP-server? Which OLAP-server does support ...
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3answers
13k views

Good example of MDX vs SQL for analytical queries

Can anybody show me a good example of MDX's advantages over regular SQL when doing analytical queries? I would like to compare an MDX query with an SQL query that gives similar results. Wikipedia ...
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1answer
207 views

Adding templated Date-Time dimension to the cube

I have a database with FactSales table that contains Date column of type I4. I have created a cube and linked dimensions via foreign keys as usual, however, since I have no DateTime table in the ...
3
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1answer
557 views

After processing complete, SSAS DB slowly consumes all available space on disk, w. high memory use also

This problem is with an SSAS 2012 SP3 (11.0.6020.0) multi-dimensional server, hosting a single cube database, containing 1 cube and 16 dimensions. Aggregations have been designed using SQL Management ...
6
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1answer
364 views

How do you index alphanumeric foreign keys on large fact tables?

I have a field that is an alphanumeric field that ideally is a encrypted field for a non-unique identifier. It's used to relate other rather large fact tables in a many-to-many relationship. I do not ...
3
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1answer
4k views

SSAS cube process time increased after making fact and dimension small

I have a cube of 55 GB size which takes around 2 Hour to process full. As I have data for last 4 years but our business wants only 2 years of data. For that, I have changed dimension and Fact views to ...
3
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1answer
2k views

SSAS cube fact and dimension relationship

I have a cube that all the tables has one row per ID and have measure in all of them except for the calendar dimension. When I view the measures in excel from Table 1 with attributes from table 2, I ...
6
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1answer
898 views

Clustered columnstore index performance SQL Server 2014

I'm setting up an OLAP database using SQL Server 2014. The core fact table has about 40,000,000 rows, 225 columns with an average row size of 181 bytes. I've been toying around with the clustered ...
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1answer
1k views

Is processing required dimensions enough or to process the entire cube?

I have four large dimensions and one of the dimension is not going to be changed, also the particular dimension didn't need to be processed. So, processing the three dimensions individually updates ...
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0answers
682 views

Handle Duplicate entries in Fact table in Data Cube

We have been constructing data cube for our project in which we are facing a problem like 1 to many relationship in the dimension tables and making entries in fact table (duplication). ...
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1answer
2k views

Having Non-Numeric values as measures in Fact table

According to my research regarding having non-numeric value as measures, I found that having non-numeric won't be an optimal one. So I planned to maintain numeric values. My scenario was "Employee's ...
2
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1answer
1k views

Update OLAP Cube data

We are using OLAP in our project and we are facing a scenario where we need to update the cube with real time data on daily basis. I need some suggestions about an optimal way for updating the data ...
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0answers
83 views

Mysql - too many Deletion - Insertion

I'm creating cron jobs for my OLAP system. I have a cron job that deletes the records from the summary table first and then insert the records in it again: Say Deleting 1 month records, and ...
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0answers
806 views

CREATE OLAP server

I have a MySQL database server along with replication server, i.e. OLTP system altogether. As I have very heavy data fetching queries for the decision making reports. I need to create data-ware house ...
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2answers
5k views

Get distinct count on calculated member?

I'm using SSAS and created a measure group that is linked to Fact_SalesMetrics on SQL Server. In that, I have seven measures. All measures have aggregation of Sum except Sales Invoice which has ...
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0answers
65 views

How to keep archive table accessible for some users which is not frequently accessible?

I have partitioned my table based on some boundary ranges. My Database is built at MSSQL server 2008 R2. I have done partitioning for a table which has 40 million records in it. Now it's time to ...