How to handle multitenant data warehouse (each customer has a unique schema)? - data-warehouse

so I am trying to set up a data warehouse for a service where each customer has their own database with a unique schema. How do I go about setting up a warehouse so each customer has their own semantic layer / relational model set up automatically (since we (centrally) do not know what is in each database) So that each customer can easily report on their data? Is there any automatic process we can follow? Am I missing something?

It depends on whether you want a consolidated view of the data, or if each customer's data is to remain segregated.
If consolidation is the objective (and there are huge benefits for a multi-tenant SAAS vendor to have a consolidated overview of customer data) then Nithin B's suggestion is good.
If separate warehouses are required, then you'll need to think about how to optimise your costs. The two biggest components will be ETL/ELT, and database hosting.
The fastest way to ETL/ELT is data warehouse automation. You'll find a good list of vendors on our web site (http://ajilius.com/competitors). Look for a solution that will give you the flexibility to meet your deployment options (cloud and/or on-premise), as well as the geographic reach you'll need for accessing customer data.
Will you be hosting your own databases or in the cloud? How much data will each tenant require? A good starting point would be PostgreSQL or SQL Server (SMP), and Ajilius gives you the flexibility to instantly migrate to MPP platforms if your needs outgrow those platforms.

There are many ways to address this.
Land all the tables in a Landing area in different schemas.
Stage the data into appropriate staging tables for dim and fact loads.
Create a dim table to identify the Customer Area. For eg: Dim_Source
Load the data into the fact tables. Any specific customers can filter the data from the facts by using the Dim_Source values.
This design would help overall Enterprise reporting as well.
Hope that helps.
I would start with a Kimball BUS Matrix.
Cheers
Nithin

Related

Master Data Management using Graph Database

I am building a master database to store all relevant information about our customers. I am using Neo4j.
Below is a sample of our model. We have Person, that can be registered in 3 of our mobile applications. (App.01, App. 02, App. 03 - We use CPF key, it is like a SSN). In those apps the user can be registered with an email. So it is represented by Email entity. Those user can have multiple address represented by Address entity.
The question is:
As I am building a Master Data, IMO, if someone query the mdm database asking for all "best" information about a person, I would return for example:
Name: John
Best email: email2 (because it has two apps using it)
Best address: addr1 (because it has tow apps using it)
So I am going to build some heuristis to define what is the "best" email and address.
For this purpose, I have some options:
I could create an edge from John to email2 and to addr1. So it's going to be easy for an user of MDM to get the "best" address/email from John.
I could build a rest API endpoint and create this heuristic in query time.
Does anyone have experience using graph database or design MDM database?
Is it a good approach?
This question is a complement for the question: Using Neo4j to build a Master Data Management
The graph data model is good to store your master data, however, your master data most likely will co-exist with operational and reference data in the form of dimensions.
if you decide to go with a graph model for your DMD, make sure that you have a well defined semantic model for the core dimension is MDM, usually:
products
customer
employees
Assets
Location
These core dimensions become attributes of your nodes.
Also, decide what DMD architecture style you are going to adopt, some popular ones are:
The Registry - Graph fits very well with this style because your master data remains in the SOS(system of record) and the references can be represented in the graph very nicely.
Master data Hub - Extra transformations ar4e required to transpose your system of record from tabular to the graph.
Master-Master. - this style fits well with your MDM in the graph if you do not have too many legacy apps that depend on your MDM.
Approach 1 would add a lot of essentially redundant information (about 2N extra relationships, where N is the number of people), and also require more complex coding to handle changes to a person's apps. And, as always when information is stored redundantly, you would have to be especially careful that inconsistencies do not creep in. But, it should be faster when querying for the "best" contact info.
Approach 2 keeps the DB the same size, but requires a more complex and slower query to get the "best" contact info. However, changing a person's apps and contact info is straightforward.
To decide which approach to use, you should consider whether DB size is an issue, and also look at your use cases and how frequently they will be performed.
Here is a simple heuristic if DB size is not an issue. Suppose G is the frequency at which you need to get a person's "best" contact info, and M is the frequency at which you need to modify a person's apps or contact info. You would pick approach 1 if the value of G/M exceeds some threshold value, K, that you would have to decide on, taking into consideration the above considerations.

When we use Datamart and Datawarehousing?

I am new to DW . When we should use the term Datamart and when we should use the term Datawarehousing . Please explain with example may be your own example or in terms of Adventureworks .
I'm don't work on MS SQL Server. But here's a generic example with a business use case.
Let me add another term to this. First off, there is a main transactional database which interacts with your application (assuming you have an application to interact with, obviously). The data gets written into the Master database (hopefully, you are using Master-Slave replication), and simultaneously gets copied into the salve. According to the business and reporting requirements, cleansing and ETL is performed on the application data and data is aggregated and stored in a denormalized form to improve reporting performance and reduce the number of joins. Complex pre-calculated data is readily available to the business user for reporting and analysis purposes. This is a dimensional database - which is a denormalized form of the main transactional database (most probably in 3NF).
But, as you may know, all businesses have different supporting systems which also bring in data in the form of spreadsheets, csvs and flatfiles. This data is usually for a single domain, such as, call center, collections so on and so forth. We can call every such separate domain data as data mart. The data from different domains is also operated upon by an ETL tool and is denormalized in its own fashion. When we combine all the datamarts and dimensional databases for solving reporting and analysis problem for business, we get a data warehouse.
Assume that you have a major application, running on a website - which is your main business. You have all primary consumer interaction on that website. That will give you your primary dimensional database. For consumer support, you may have a separate solution, such as Avaya or Genesys implemented in your company - they will provide you the data on the same (or probably different server). You prepare ETLs to load that data onto your own server. You call the resultant data as data marts. And you combine all of these things to get a data warehouse. I know, I am being repetitive but that is on purpose.

Ecommerce frontend split databases

Until now I've worked on a web app for keeping record of different products from different warehouses in regards to inventories and transactions etc.
I was asked to do an ecommerce front end for selling products from these warehouses and I would like to know how should I approach this problem?
The warehouses web app has a lot of logic and a lot of products and details and I don't know whether to use the same databases(s) for the second app by mingling the data in regards to user mgmt, sales orders and etc.
I've tried doing my homework but for the love of internet I don't even know how to search, if I'm placed on the right track I shall retreat to my cave and study.
I'm not very experienced in this matter and I would like to receive some aid in deciding how to approach the problem, go for a unified database or separated one-way linked datbases and how hard would it be to maintain the second approach if so?
Speaking of warehouses, I believe that is what you should do with your data, e.g. roll each and every disparate data source into a common set of classes/objects that your eCommerce store consumes and deals with.
To that end, here are some rough pointers:
Abstract logic currently within your inventory app into a middle tier WCF Service that both your inventory app and eCommerce app can consume it. You don't want your inventory app to be the bottleneck here.
Warehouse your data, e.g. consolidate all of these different data sources into your own classes/data structures that you control. You will need to do this to create an effective MVC pattern that is maintainable and sustainable. You don't want those disparate domain model inventories to control your view model design.
You also don't want to execute all of that disparate logic every time you want a product to show to the end user, so cache the data in a well indexed, suitable table as described above for high availability that you can get to using Entity Framework or similar. Agree with the business on an acceptable delay and kick off your import/update processes on a schedule.
Use Net.Tcp bindings on your services to move your data around internally. It's quick, it's efficient and there is very little overhead compared to SOAP when dealing in larger data movements.
Depending on scale required, you may also want to consider implementing a WCF Service purely for the back-end of your ecommerce store, that deals only in customer interactions with the underlying warehoused data sources, this could then warrant its own server eventually if the store becomes popular. Also, you could figure in messaging eventually between your SOA components, later down the line.
Profit. No, seriously!
I hope this helps. Good luck!

Datawarehouse for analytical CRM

Is it beneficial to pull the data from Datawarehouse for analytical CRM application or it should be pulled from the source systems without the need of Datawarehouse??....Please help me answering.....
For CRM it is better to fetch the data from datawarehouse. Where a data transformations developed according to the buiness needs using various ETL tools, using this transofrmations you can integrate the CRM analytics for analysing the large chunk of data.
I guess the answer will lie in a few factors
what data you need,
the granularity of that data and,
the ease of extract
If you need data that you will need to access more than one source system, then you will have to do the joining of that data between them. One big strength of getting the data from a DWH, is that they tend to have data from a number of source systems and are well connected across these source systems with busienss rules being applied consistently across them.
A datawarehouse should have lowest granularity data, but sometimes, for pragmatic reasons, decisions may have been taken to partly summarise the data, thus you may not have the approproate granularity.
The big advantage of a DWH is that it is a simle dimensional model structure (for a kimball star schema any how), so as long as the first two are true, I would always get my data from the DWH.
g/l!
Sharing my thoughts on business case to pull from datawarehouse rather than directly from CRM system would be -
DWH can hold lot more indicators for Decision making and analysis at enterprise level across various systems than a single system like CRM. Therefore if you want to further your analysis on CRM data you can merge easily information from other system to perform better analytics/BI from DWH.
If you want to bring conformity across systems for seeing data of customer with single view. For example, you can have pipeline and sales information from CRM and then perform revenue calculation in another system for the same customer. Its possible that you want both sets of details in single place with same customer record linked to both measures.Then you might want to add Risk (Credit information) from external source into the same record in DWH. It brings true scability in terms of reporting and adhoc requests.
Remove the non-core work and dettach the CRM production system from BI and reporting (not talking of specific CRM reports). This has various advantages both terms of operations and convinence. You can google on this subject more to understand the benefits.
For now these are the only points that come to me. I will try adding more thoughts later.
P.S: I am more than happy to be corrected :-)

How to design data vault schema for efficient queries for BPMS system?

Current situation:
We have a BPMS (business process management suite) in place. There is increasing demand on historical and operative reports. The data model in the BPMS is not designed for historical queries. So we are analysing the possible solutions.
Solution in mind:
The idea is to push data on events in flow to an external database. Typical events in BPM are: new process instance was created, status changed, a step in the process was performed or status of the process instance was changed. Data vault is besides the star schema one of the interesting alternatives. Let’s assume there are two Hubs: PI (processitem instances) and OU (organisational unit) and a Link table LINK_PI_OU. Each time the process item is assigned to an organisational unit a new line will be added to the link table. The LOAD_DATE in the link table contains the datetime when this record was added. The record in the link table with the latest LOAD_DATE shows the current assignment of the process instance.
Question:
Let’ assume the business wants to know to whom all open process instances are currently assigned grouped by organisational unit.
How will a query look like for this report? Can it really be performant?
Or am I on the complete wrong way?
In general terms I didnt think that Data-Vault is intended to be an end user report layer or even a faux transactional system.
Im not completely clear on your archectiture, but in my understanding D-V is a historical repository that keeps all data for an enterprise that feeds a (Kimball/Inmon)datawarehouse. So in high level terms ...
Transaction systems => D-V => DWH => (cubes =>) users
This being the case, I wouldnt be posing queries to a Data Vault, instead I would write some ETL to populate a data warehouse and pose queries at the DWH.
The other view, I guess, is that you could build a set of views on top of the D-V, that would hide the structure from users, but I think I'm a bit of a purist and would go for a DWH.
As #Marcud D said, Data Vault is the model of Data Warehouse and usually when using DV modelling, you have to build data marts from DV for reporting purposes. I think that organizational unit should be modeled as Satellite table, not as Hub table. So, in any way, you should build a query to feed a specific data mart from DV model and then use it for reporting purposes.

Resources