Sunday, November 29, 2015

Analysis Services: How to stop showing records when unrelated dimensions are used with measures?

It is very common to see an Analysis Services database (or a cube) that holds multiple measure groups. If your cube holds multiple measure groups, then you have many number of dimensions and they might not link with all measure groups. In that case, what if a dimension not linked (or unrelated) is used when analyzing a measure in particular measure group?
By default, if an unrelated dimension is used with a measure, dimension is forced to use its top level for showing the value. Example, if Sales Amount from Sales Summary measure group is analyzed with Reseller dimension which is unrelated, result will be as below;


This is controllable. We can stop showing records, when a measure is being analyzed by an unrelated dimension. All we have to do is, set false for a measure group property called IgnoreUnrelatedDimensions.


Once processed, you can test the same and result will be something like below;


Saturday, November 28, 2015

Analysis Services: I see a new measure group when a measure is created with Distinct Count

Have you noticed that a new measure group is automatically created if you have created a new measure with Distinct Count usage? Microsoft Analysis Services create this not because of anything else, it is for improving the performance when it comes to specific analysis such as how many sales reps have sold a particular product.

You can create one with Cube Designer -> Cube Structure.


And once they are created, separate measure group are created;


And I will be able to see how many employees have sold a particular product in each year;


Friday, November 27, 2015

Microsoft SQL Server Code Names for versions and features

Microsoft SQL Server team used/uses various code names for SQL Server versions and some of its features, here are some of them found in the web. I tried to match the best image can find in the web, not exactly sure whether it is the right picture, hence please let me know if I have used wrong pictures.


Version/Feature Code Name
SQL Server 6.0 Enterprise ManagerStarfighter
SQL Server 6.0 AgentStarfighter II
SQL Server 6.5
SQL Server 7.0Sphinx
SQL Server 7.0 OLAP ServicesPlato
SQL Server 2000 (32-bit)Shiloh
SQL Server 2000 (64-bit)Liberty
SQL Server Reporting Services 2008Rosetta
SQL Server 2005Yukon
SQL Server Analysis Services 2005Picasso
Database Design and Query ToolsDaVinci
SQL Server 2005 Mobile EditionLaguna
SQL Server 2008Katmai
SQL Report Designer 2.0Blue
SQL Server 2008 R2Killimanjaro
SQL Server 2012Denali
SQL Server Developers (Data) ToolsJuneau
SQL Server Columnstore IndexAppollo
SQL Server 2014 (In-memory OLTP)Hekaton

Wednesday, November 25, 2015

How can I see the pages used by my table?

Not always, but there are instances that you need to see the data pages used by SQL Server for holding data in our tables. There are few ways of seeing them, the easiest way is, using two undocumented functions called sys.fn_PhysLocFormatter and sys.fn_PhysLocCracker. These two were initially released with SQL Server 2008 and they are still available. Not sure why they are still marked as undocumented but information throw from them is really useful.

Here is a test code on it;

USE AdventureWorksDW2014;
GO

-- Checking with fn_PhysLocFormatter function.
-- This shows file id, page id and slot id together.
SELECT sys.fn_PhysLocFormatter (%%physloc%%) AS RID, * FROM dbo.FactInternetSales;


-- If you need file, page and slot separately, 
-- fn_PhysLocCracker function can be used.
SELECT sys.fn_PhysLocFormatter (%%physloc%%) AS RID, RID_c.file_id, RID_c.page_id, RID_c.slot_id, * 
FROM dbo.FactInternetSales
 CROSS APPLY sys.fn_PhysLocCracker (%%physloc%%) AS RID_c
ORDER BY RID_c.file_id, RID_c.page_id, RID_c.slot_id;


Tuesday, November 24, 2015

Changing from FULL to SIMPLE recovery model reduces the log file size?

A concern related to large log file or ldf file still appears in many forums, it is very common to hear/see a questions like my database log file has grown for GBs, why and how can I reduce it, can I just reduce it by changing the recovery model from FULL to SIMPLE.

First thing you need to understand is, how log file truncation works with FULL and SIMPLE recovery model. FULL Recovery model does not truncate the log file until a transaction log backup is performed. But SIMPLE recovery model automatically truncates the log making the log vacant for next transactions rather expanding or growing the file. There are few exceptions in FULL, read my article Log is getting automatically truncated with FULL Recovery Model  for more info.

Now if your database in FULL recovery model and you see a large log file, can you reduce it by just changing the recovery model. Recommendation is not change as you will lose all you transaction records in log file but if you do not want them you can change. However it does NOT reduce the size of the log file. Once changed, it will truncate the file but will not release the free space unless you perform the SHRINKFILE operation for the log file. So the conclusion is, changing the recovery model from FULL to SIMPLE does not reduce the size but truncates. Shrinking file is required for reducing the file size.

Here is a small test for verification.

This code creates a database and a table. The default recovery model is FULL for this database. It backs up the database once. It makes sure that the backup chain is established.

CREATE DATABASE TestDatabase;
GO

USE TestDatabase;
GO

CREATE TABLE dbo.TestTable
(
 Id int identity(1,1) primary key
 , Value1 char(4000) not null
 , Value2 char(4000) not null
);

-- take a backup
BACKUP DATABASE [TestDatabase] TO  DISK = N'C:\Program Files\Microsoft SQL Server\MSSQL12.SQL2014\MSSQL\Backup\TestDatabase.bak' 
WITH NOFORMAT, NOINIT,  NAME = N'TestDatabase-Full Database Backup', SKIP, NOREWIND, NOUNLOAD,  STATS = 10
GO

Here is the current file size.


This code adds records growing both data and log files.

INSERT INTO dbo.TestTable
 (Value1, Value2) VALUES (REPLICATE('a', 4000), REPLICATE('a', 4000));
GO 1000000

As you see, log file has been grown and it is not getting either truncated or shrunk automatically.


Let's change the recovery model and see.

USE master;
GO
ALTER DATABASE TestDatabase SET RECOVERY SIMPLE WITH NO_WAIT;
GO

If you check the size again, you will see the same as it does not release the free space back to OS. Let's shrink the file and see.

USE TestDatabase;
GO
DBCC SHRINKFILE (TestDatabase_log, TRUNCATEONLY);

All as we wanted.


Monday, November 23, 2015

Can I use Standard Edition of SQL Server for implementing my Business Intelligence solution?

I always get this questions from my clients, companies I consult and people who work on BI implementation. Most of the companies initially purchase Standard Edition of SQL Server because of the cost and gradually upgrade to Enterprise. Can we really implement a BI solution with Standard Edition?


Microsoft offers multiple editions of SQL Server, mainly two premium editions and two core editions. Microsoft Analytics Platform System (Parallel Data Warehouse + HDInsight) and Enterprise are premium editions and Business Intelligence and Standard are core editions. If you have purchased Standard Edition, yes you can still implement a BI solution but with many limitations.

Generally, it is not recommended to have Standard Edition for large BI implementations. For managing large volume, you need Enterprise Features like partitioning, data compression and columnstore indexing that are not available with Standard Edition. Therefore, if it is a either small or middle-scale, then Standard Edition can be used.

There less number of functionalities with Standard Edition Integration Services too. Some of main missing features are Persistence Lookup, data mining query transformations and fuzzy lookup and grouping.

It is very important to consider Analysis Services features. As you know, it supports two types of Models; Multidimensional and Tabular. Standard Edition does not support Tabular Model. This forces you to go for multidimensional model though it is bit complex and time-consumed that Tabular. In addition to that, scalable shared databases, synchronizing, perspective, proactive caching and write-back features are not supported with Standard Edition.

Now you know whether you can implement your BI solution with Standard Edition or not. You may consider Business Intelligence Edition if you need more features specifically on Analysis Services end.

Sunday, November 22, 2015

SQL Server Brain Basher of the Week #035 - Database size

Microsoft SQL Server supports creating small databases as well as very large databases. This week question is based on database sizes, here is the one;

What is the minimum relational database size and maximum relational database size that can be set when creating a database?

When you create a database, system takes a copy of the model database as a template for creating it. The default size of the data file set with model database is 5MB. This stops you for reducing the size of the data file when creating your database. If you try to reduce it for 1MB, this is what you get;


You can reduce the model database data file to minimally 3MB. Once it is set, you can create your database with a data file sized to 3MB.


Based on above tests, we know that the smallest size that can be set with our data files is 3MB (not sure, but there can be some other way to reduce this, will see, however, there is no necessity for having a database like that unless there is a specific and special requirement).

The largest database size support by SQL Server is 524 PB. Almost all editions support creating database with this size, only exception is Express Edition that support only 10GB size databases.


Saturday, November 21, 2015

SQL Server Brain Basher of the Week #034 - Analysis Services Security

Security is the most important area that needs to be addressed with many solution and same goes to your Business Intelligence solutions implemented with Microsoft Analysis Services. Typically, all database management systems provide multiple server roles for managing permission, and allow us to extend it either creating custom server roles or database roles. This week question is based Analysis Services server roles;

How many server roles are exist with Analysis Services and what are they?

You do not want to think about this much. Analysis Services offers only one server level role called as Administrators. This cannot be modified and we cannot create any additional roles, but we can add members to this role providing admin rights to anyone required. However system allows us to create additional database level roles which are limited to specific databases.

You can access Administrators role by getting properties of the instance and selecting Security property.


Database roles can be created by accessing Roles node under the database.



Friday, November 20, 2015

Storing datetime with time zone offset and retrieve with required time zone offset

Nothing new but posting as it is something important when working with multiple time zone offsets. If you have to store requests coming from all around the world with the time local to them, sysdatetimeoffset type has to be used with the column and when convert to a different time zone offset, switchoffset function has to be used. Here is an example;

USE tempdb;
GO

-- creating table for holding date and time with time zone offset
CREATE TABLE dbo.TestTable
(
 Id int primary key,
 DateEntered datetimeoffset(0) not null index ix_TestTable clustered
);

-- inserting values
INSERT INTO dbo.TestTable
VALUES
(1, '2015-11-17T02:10:33.430+10:30') -- receiving from Sydney
, (2, '2015-11-17T05:30:21.110+05:30') -- receiving from Sri Lanka
, (3, '2015-11-17T14:24:22.660+00:00') -- receiving from USA

-- Retrieving all dates for Sri Lanka time zone offset
SELECT Id, CONVERT(datetime, SWITCHOFFSET(DateEntered, '+05:30')) DateEntered
FROM dbo.TestTable;

Thursday, November 19, 2015

SQL Server Management Studio - October 2015 Release

Have you tried out latest SQL Server Management Studio? It is available as the October release. It can be used with SQL Server 2016 through SQL Server 2005 and supports side-by-side installation.

You can download it from here.

Here are some of the features/functionalities added with this release (from MSDN)
  • New modernized lightweight web installer
  • New Always Encrypted column encryption wizard 
  • New Column Master Key (CMK) rotation dialog
  • New stretch database monitor 

Wednesday, November 18, 2015

Power BI: Showing YTD values

Still not all time intelligence functions are working but some of them can be used with DAX. If you have a requirement for showing YTD, QTD and MTD, and they are not available with your either multi-dimensional or tabular model, DAX can be used just like we use in PowerPivot for creating them. However, if you try to use functions like PREVIOUSYEAR, PREVIOUSDAY, it might not work (it did not work for me) as all functionalities related to time intelligence have not been added to Power BI yet.

Here is the way of adding YTD measure to a model created in Power BI extracting data from SQL Server. Once data is loaded, go to data tab (green colored box) and click on new measure (red colored box) button for creating a new measure. Then use the following expression for calculating YTD.

SalesAmountYTD = CALCULATE(SUM(FactInternetSales[SalesAmount]), DATESYTD(DimDate[FullDateAlternateKey]), ALL(DimDate))


Once added, it can be used with desired graphical element;



Tuesday, November 17, 2015

Can we use user-defined hierarchies in the model with Power BI?

Power BI is becoming richer and richer with its functionalities and will be surly the best in terms of BI client tools. Since it is still being completed, some important functionalities are still missing and sometime it makes us very uncomfortable to use it. One of the key object we build with models is hierarchy, that is very usable when navigating via a set defined with levels using dimension attributes. This navigation is called as Drilling Down. Most common and famous example is, a hierarchy on date dimension that starts from Year, then Semester, Quarter, Month and Date. Power BI does not recognize these user-defined hierarchies defined in models, hence drilling down was initially impossible. I believe that this is being addressed and it will be available in future releases, until that a workaround is given.

If you have installed AsdventureWorks Tabular Model, it has some hierarchies defined. The following shows a hierarchy defined with Date dimension.



And if you connect with this source using live connection;



And expand date dimension, you will not see the hierarchy.



However, latest version of Power BI allows you to configure a hierarchy within the chart. All you have to do is, drag and drop attributes to Axis box, forming a hierarchy. The following shows how it looks like when it is added.




Now drilling-down is possible with the chart. It is not enabled by default, the icon in the right-top has to be used for enabling it. Once enabled, you can click on the bar, example, bar that represents 2013 and go into semesters related to it. For drilling-up, the icon in the left-top has to be used.

This works fine without any issue and this is the way of implementing drilling-down until we get a version that supports user-defined hierarchies in models.




Monday, November 16, 2015

Understanding Reporting and Analysis in Business Intelligence solutions

Every company implements a business intelligence solution for tracking and improving the business performance through reporting and analysis, setting it as the ultimate goal of business intelligence solution. Some solutions completely focus on analysis only and some focus on reporting only but most focus on both, making sure that solution delivered addresses requirements coming of all level of the company. What is the different between Reporting and Analysis with BI?

Reporting


This is the main communication channel used for getting information from BI solution. Formal reports or operational reports are not recommended through BI solution but production reports, interactive reports (up to some extent) and dashboard reports are common. Most reports show summarized values and they are printable. It is not uncommon to see tabular reports but reports with graphical elements are the most common. When planning, audience needs to be understood, need to have a good knowledge on how reports need to be viewed and delivered. There are mainly two types of reports that can be delivered through a BI solution;
  • IT-provided reports
    Reports that are developed and managed by developers are called as IT-provided reports. These reports are developed based on requirements given by business users. Business users have no facilities to modify reports but content of the reports can be changed using filters added or using interacting features such as expanding/collapsing enabled in the report.
  • Self-service reports
    Self-service reports are authored by business users without getting support from IT. Special tools that are more user-friendly for business users have to be given, empowering business users. Tools should support authoring simple reports such as production report as well as complex reports such as dashboard reports. Though IT has no involvement with this, repository that holds data required with business terms has to be supplied by IT (example, data warehouse, or models) and sometime, IT manages developed reports too.
Analysis


Analysis is detail examination or interpretation of data delivered by BI solution. Smart business users explorer data in the model and perform specific examinations for seeing the insight or find a hidden pattern. Example, these business users will use tools like Excel, Power BI, Tableau for creating their own models or doing their own experiments. General users do the same but not with specialized tool but with reports and dashboards. Generally, following analytical requirements are addressed with BI solutions;
  • Interactive analysis
    This type of analysis requires key BI functionality such as slicing and dicing for analyzing data with various segments or dimensions. Results of these analysis can be published as reports or can be used for improving business process such as promotions.
  • Dashboard and scorecards
    Combination of various KPIs and summarized information with graphical widgets are shown with dashboards and scorecards, allowing users to analyze data with functionalities like drilling down and drilling through.
  • Data mining (machine learning)
    This allows users to do various experiments with data using machine learning algorithm for understanding the trends and patterns related business processes and using them for improving the business.


Sunday, November 15, 2015

Trying to connect on-prem Analysis Services using Power BI Analysis Services Connector?

Although Power BI Pro allows us to connect with On-Prem Analysis Services Tabular instances for consuming live data into dashboards and report, there are limitations on it. If you try to configure Power BI Connector with On-Prem Analysis Services Tabular instance using an effective account (such as onmicrosoft.com account) without an Active Directory configured domain or using an active directory account without syncing it with Azure Active Directory, you will not be able to configure. Here is what I get when trying to configure Power BI Analysis Services Connector with my Tabular Instance installed in my standalone laptop.


All Prerequisites are listed at https://powerbi.microsoft.com/en-us/documentation/powerbi-analysis-services-connector/.

Here are important things to be remembered;
  • Only SQL Server Analysis Services Tabular models are supported for Power BI.
  • The connector has to continue running and the computer where it is installed has to remain on.
  • Power BI Analysis Services Connector and the Data Management Gateway on the same computer cannot be co-exist.
  • The Analysis Services server is domain joined.
  • If you use a .onmicrosoft.com email address, you'll need to sync your Active Directory to Azure Active Directory using Azure Active Directory Sync (DirSync). T