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Introduction
Tabular Model is a new feature in SQL Server 2012. Tabular models are in-memory databases in
Analysis Services. They use state-of-the-art compression algorithm and multi-threaded query
processors named as VertpPaq (xVelocity in-memory analytics engine). This enable fast access to
tabular objects and data by reporting applications such as MS Excel.
Tabular Models are created in SQL Server Data Tools (SSDT). SSDT is the upgraded version of BI
developer. SSDT is also used to develop Reports, Integration Services and Multidimensional
projects. Tabular Model project is deployed as Analysis Services database just like
Multidimensional projects. In Tabular Model, we can add partitions for optimization purposes.
Row-level security can also be implemented in Tabular Model. We can also import data from
external sources to make it a part of the model. We can add relationships, measures and
calculated columns on the tabular data in the model. Hierarchies are also supported in Tabular
model as in multidimensional model. This makes it more do-able and easy to go with project
type in SSAS. As Tabular Model is deployed as Analysis Services database, client applications can
connect to the deployed model for reporting purposes.
Analysis services provides three approaches to develop business intelligence semantic models;
1. Tabular
2. Multidimensional
3. PowerPivot
Tabular Model is based on relational structure such as tables and relationships for modeling of
data. Multidimensional and data mining are based on OLAP (cubes and dimensions). PowerPivot
is a self-service BI tool.
Tabular Model support data access through two modes;
Cached Mode In cached mode, you can integrate data from multiple sources including
relational databases, data feeds, and flat text files.
Direct-Query Mode In this mode, you can by-pass the In-Memory model and allow client
applications to query directly from the relational database. In short, Tabular model is designed to
query huge data with much lesser response time in different client application, especially in MS
Excel.
Comparing With Multidimensional Model
With the release of Tabular Model, there are few decisions by Managers that has to be made.
Some common questions are;
Question 1: When to use Tabular Model and Multidimensional Model?
Answer: Both Tabular and Multidimensional Models are the part of Analysis Services. Both are
developed in SSDT. The answer lies within the data to be used in the model. If you have huge
data, like in TBs, to process in the model, then Multidimensional Model is the best suite for you.
Tabular Model are more compressed than Multidimensional but it also requires more memory to
load and process the data in memory. PowerPivot Models are for even lesser data size.
Question 2: What do we mean by 'External Data' or 'External Source'?
Answer: We can import data in Tabular Model and PowerPivot from External sources. These can
be text files, excel files, data feeds and even some document formats. In multidimensional, you
can only load data from relational sources using OLEDB and managed providers.
Question 3: What is the core benefit of Tabular Model?
Answer: The core benefit is that they are easy to implement as PowerPivot. You can develop
more efficient and effective solution. The data processing is very fast and it is easy to
understand. It uses DAX as programming language. DAX is quite similar to Excel formula
language. Comparing with PowerPivot, Tabular Model is a centralized solution. The data is more
organized and authenticated as compared in PowerPivot. PowerPivot is an ad-hoc pattern to
access data from the source and is a part of Self-Service BI solution. Tabular Model is the
Corporate-BI solution.
Question 4: Should we convert the current Multidimensional Models to Tabular?
Answer: NO. The project types are not interchangeable. And it will not be an effective decision to
convert the multidimensional model into Tabular model. It is best to use the model for the new
requirements.
Analysis Services 2012 Two in One Product
Most important aspect of Analysis Services 2012 is that it is two products in one. In SQL Server
2008 R2 and before, we only had Multidimensional Model option in Analysis services. But in SQL
Server 2012, you can choose between Multidimensional and Tabular Model while installing SSAS
instance. You need to have separate instance for both if you want to use both, multidimensional
and tabular model. In the figure below, you can see that on Feature selection page, there is only
one selection for Analysis Services;
But when you pass on to the Analysis configuration page, there you will see a radio button for
Server Mode selection. The options are; a. Multidimensional and Data Mining Mode b. Tabular
Mode
Licensing
Analysis services 2012 is available in the following editions of SQL Server;

SQL Server Standard Edition

SQL Server BI Edition

SQL Server Enterprise Edition
In SQL Server Standard edition, you can only have Multidimensional Mode. SQL Server BI edition
and SQL Server Enterprise editions have both Multidimensional and Tabular Mode. In terms of
Analysis Services functionality, these two editions are the same; the only difference between
them is that SQL Server Business Intelligence edition licensing is based on buying a server license
plus Client Access Licenses (CALs), whereas SQL Server Enterprise edition is licensed on a per-
CPU core basis. (You can no longer license SQL Server Enterprise edition on a server-plus-CALs
basis as was possible in the past.) In SQL Server Business Intelligence and SQL Server Enterprise
editions, both Tabular and Multidimensional models contain all available features and can use as
many cores as the operating system makes available. The upshot of this is that it could be more
expensive in some situations to use Tabular than Multidimensional because Multidimensional is
available in SQL Server Standard edition and Tabular is not. If you have a limited budget, already
have existing Multidimensional skills, or are willing to learn them, and your data volumes mean
that you do not need to use Multidimensional features such as partitioning, it might make sense
to use Multidimensional and SQL Server Standard edition to save money. If you are willing to pay
slightly more for SQL Server Business Intelligence edition or SQL Server Enterprise edition,
however, then licensing costs should not be a consideration in your choice of model.
A hint to Self-Service BI and Corporate BI
Over the last few years, trends and demand of BI have significantly changed. Now, users are
more interested in having the hold on their data and analyze it according to their own run-time
requirement on the spot. Prior to that, they had to involve an IT professional to develop complex
reports for them. This is Corporate BI. This scenario still exists but for analysis work, it becomes
more cost and time consuming for engaging IT professional for the analysis work. This resulted in
a new Self-Service BI. There are tools available in the market like QlikView and Tableu that
enables users to query their own data in a user friendly interface. Analysis Services is a
corporate-BI tool by MS as you need an IT professional to design and build an Analysis Services
database. There are disadvantages of self-service BI like poor-quality data, lack of integration
between multiple source systems, etc. Still, self-service BI is high on demand and the reason is
that most of the data users think that in most cases, the time consuming step of creating a data
warehouse is un-necessary in their initial scenario. MS, as a software company could not ignore
this market demand, so in 2010, it released its own serf service BI tool, PowerPivot. Tabular
Model resembles a lot to PowerPivot and a refined version of PowerPivot as you get the
scalability and manageability in the Tabular Model. PowerPivot is more Agile and Self-Service BI
tool.