💎SQL Reloaded: Extended LTrim/RTrim in SQL Server 2022 (Before and After)

In SQL Server 2022, the behavior of LTrim (left trimming) and RTrim (right trimming) functions was extended with one more string parameter. When provided, the engine checks whether the first parameter starts (for LTrim), respectively ends (for RTrim) with the respective value and removes it, the same as the space character char(32) was removed previously:

-- prior behavior of LTrim/RTrim
DECLARE @text as nvarchar(50) = '  123  '
SELECT '(' + LTrim(@text) + ')' LeftTrimming
, '(' + RTrim(@text) + ')' RightTrimming
, '(' + Ltrim(RTrim(@text)) + ')' Trimming1 -- prior SQL Server 2017
, '(' + Trim(@text) + ')' Trimming2 -- starting with SQL 2017

LeftTrimming	RightTrimming	Trimming1	Trimming2
(123 )	( 123)	(123)	(123)

Here's the new behavior:

-- extended behavior of LTrim/LTrim (SQL Server 2022+)
DECLARE @text as nvarchar(50) = '123abc123abc'
SELECT LTrim(@text , '123') LeftTrimming
, RTrim(@text , 'abc') RightTrimming;

LeftTrimming	RightTrimming
abc123abc	123abc123

 Previosly, to obtain the same result one could write something like:

-- prior solution via Left/Right for the same (SQL Server 2000+)
DECLARE @text as nvarchar(50) = '123abc123abc'
SELECT CASE WHEN Left(@text, 3) = '123' THEN Right(@text,Len(@text)-3) ELSE @text END LeftTrimming
, CASE WHEN Right(@text, 3) = 'abc' THEN Left(@text,Len(@text)-3) ELSE @text END  RightTrimming

-- prior solution via "LIKE" for the same (SQL Server 2000+)
DECLARE @text as nvarchar(50) = '123abc123abc'
SELECT CASE WHEN @text LIKE '123%' THEN Right(@text,Len(@text)-3) ELSE @text END LeftTrimming
, CASE WHEN @text LIKE '%abc' THEN Left(@text,Len(@text)-3) ELSE @text END  RightTrimming

As can be seen, the syntax is considerable simplified. However, there are few the situations when is needed. In the past I had to write code to remove parenthesis, quotes or similar characters:

-- removing parantheses
DECLARE @text as nvarchar(50) = '(testing)'
SELECT LTrim(@text , '(') LeftTrimming
, RTrim(@text , ')') RightTrimming
, RTrim(LTrim(Trim(@text), '('), ')') Trimming 

-- removing double quotes
DECLARE @text as nvarchar(50) = '"testing"'
SELECT LTrim(@text , '"') LeftTrimming
, RTrim(@text , '"') RightTrimming
, RTrim(LTrim(Trim(@text), '"'), '"') Trimming 

The Trim for the 3rd value in both queries was used to remove the eventual spaces before the character to be replaced:

-- removing paranteses with lead/end spaces
SELECT RTrim(LTrim(Trim('   (testing)   '), '('), ')');

Then I thought, maybe I could use the same to remove the tags from an XML element. I tried the following code and unfortunately it doesn't seem to work:

-- attempting to remove the start/end tags from xml elements
DECLARE @text as nvarchar(50) = '<string>testing</string>'
SELECT LTrim(@text , '<string>') LeftTrimming
, RTrim(@text , '</string>') RightTrimming
, RTrim(LTrim(Trim(@text), '<string>'), '</string>') Trimming

LeftTrimming	RightTrimming	Trimming
esting</string>	<string>te	e

That's quite an unpleasant surprise!  In exchange, the value type can be defined as XML and use the following code to obtain the needed result:

-- extracting the value from a tag element
DECLARE @text XML = '<string>testing</string>'
SELECT @text.query('data(/string)') as value

Happy coding!

📦Data Migrations (DM): Conceptualization (Part IV: Data Access)

Data Migrations Series

Once the data sources for a Data Migration (DM) were identified the first question is how the data can be accessed. The legacy systems relying on ODBC-based databases are in theory relatively easy to access as long they allow the direct access to their data, which would enable thus a pull strategy. Despite this, there are organizations that don’t allow the direct access to the data even for read-only operations, being preferred to push the data directly to the consumers (aka push strategy) or push the data to a given location from where the consumer can use the data as needed (aka hybrid strategy). 

The direct access to the data allows in theory the best flexibility as the solution can extract the data when needed and this especially important during the initial phases of the project when the data need to be pulled more frequently until the requirements and logic is stabilized. A push strategy tends to add additional overhead as usually somebody else oversees the data exports, respectively the data need to be prepared in the expected format. On the other side, it would make sense to make an exception for a DM and allow the direct access to the data. 

 Hybrid strategies tend to be more complex and require additional resources or overhead as the data are stored temporarily at a separate location. Unfortunately, in certain scenarios this is the only approach can be used. Are preferred data files that allow keeping the integrity of the data and facilitate data consumption. Therefore, tabular text files or JSON files are preferred in the detriment of XML or Excel files. It’s preferable to export one data structure individually then storing parent-child solutions even if the latter can prove to be useful in certain scenarios. When there’s no other solution one can use also the standard reports available in the legacy systems.

When storing data outside the legacy systems for further processing it’s recommended to follow organization’s best practices, respectively to address the data security and privacy requirements. ETL tools allows accessing data from password protected areas like FTP, OneDrive or SharePoint. The fewer security layers in between the lower is in theory the overhead. Therefore, given its stability and simplicity FTP might prove to be a better storage solution than OneDrive, SharePoint or other similar technologies.

Ideally the extraction/export mechanisms should use the database objects that encapsulate already the logic in the legacy systems otherwise the team will need to reengineer the logic – for master data this can prove to be easy, though the logic of transactional data like on-hand or open invoices can be relatively complex to reengineer. Otherwise, the logic can be implemented directly in the extraction/export mechanisms or sometimes is more advisable to create database objects (usually on a different schema) on the legacy systems and just call the respective objects. 

When connecting directly to the data source it’s advisable using the data provider which allows the best performance and flexibility, however several tests might be needed to determine the best fit. It would be useful to check the limitations of each provider and find a stable driver version.  OLEDB and ADO.Net data providers provide in general a good performance, though native drivers of the legacy systems can be a better option upon case. 

Some legacy systems allow the access to their data only via service-based technologies like OData. OData tends to have poor performance for large data exports than standard access methods and therefore not indicated in such scenarios. In such cases might be a good idea to export the data directly from the legacy system. 

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💠🛠️🪄SQL Server: Undocumented (Part III: SQL Server CPU Utilization via the Ring Buffer)

Introduction

If no proper monitoring solution of the SQL Server and the hosting server is in place to review the CPU utilization, one can use the Scheduler Monitor buffer provided by the undocumented sys.dm_os_ring_buffers data management view (DMV). Introduced with SQL Server 2005, the DMV provides significant amount of diagnostic memory information in XML form via several buffers: Resource Monitor, Out-of-Memory, Memory Broker, Buffer Pool, respectively Scheduler Monitor buffer [2]. A ring buffer is a recorded response to a notification [1].

The view changed between the various versions of SQL Server, while with the introduction of Always On availability groups in SQL Server 2017 further buffer rings were made available (see [5]).

Warning:

According to Microsoft (see [4] the sys.dm_os_ring_buffers is provided only for information purposes, the future compatibility post SQL Server 2019 being not guaranteed!

Querying the Scheduler Monitor Buffer

Within the Scheduler Monitor buffer, the DMV stores a history of 4 hours uptime with minute by minute data points (in total 256 entries) with the CPU utilization for the SQL Server, other processes, respectively the system idle time as percentages. It allows thus to identify the peaks in CPU utilization and thus to determine the intervals of focus for further troubleshooting. As the data are stored within an XML structure, the values can be queried via the XQuery syntax as follows: 

-- cpu utilization for SQL Server and other applications
DECLARE @ts_now bigint = (SELECT cpu_ticks/(cpu_ticks/ms_ticks)
        FROM sys.dm_os_sys_info); 

SELECT DAT.record_id
, DAT.EventTime
, DAT.SQLProcessUtilization 
, DAT.SystemIdle 
, 100 - (DAT.SystemIdle + DAT.SQLProcessUtilization) OtherUtilization
FROM ( 
	SELECT record.value('(./Record/@id)[1]', 'int') record_id
	, record.value('(./Record/SchedulerMonitorEvent/SystemHealth/SystemIdle)[1]', 'int') SystemIdle 
	, record.value('(./Record/SchedulerMonitorEvent/SystemHealth/ProcessUtilization)[1]', 'int') SQLProcessUtilization
	, EventTime 
	FROM ( 
		SELECT DATEADD(ms, -1 * (@ts_now - [timestamp]), GETDATE()) EventTime
		, [timestamp]
		, CONVERT(xml, record) AS [record] 
		FROM sys.dm_os_ring_buffers 
		WHERE ring_buffer_type = N'RING_BUFFER_SCHEDULER_MONITOR' 
		  AND record LIKE N'%<SystemHealth>%') AS x 
	) AS DAT
ORDER BY DAT.record_id DESC;

If the SQL Server is not busy as all, the SQL Server utilization time may tend to 0%, while the system idle time to 90%. (It's the case of my SQL Server lab.)

CPU Utilization for my home SQL Server lab

Notes:

If the server was restarted within the last 4 hours, then the points will have a gap between two readings corresponding to the downtime interval.

The query is supposed to run also on Linux machines, though the SystemIdle time will be 0. One can thus consider the SQL and non-SQL CPU utilization.

Storing the History

The above query can be run on a regular basis (e.g. every 3-4 hours) via a SSIS package and push the data into a table for historical purposes. Because is needed to have a continuous history of the readings, it's better if the gap between runs is smaller than the 4 hours. No matter of the approach used is better to check for overlappings when storing the data:

-- dropping the table
-- DROP TABLE IF EXISTS dbo.T_RingBufferReadings 

-- reinitilizing the history
-- TRUNCATE TABLE dbo.T_RingBufferReadings

-- creating the table
CREATE TABLE dbo.T_RingBufferReadings (
  Id bigint IDENTITY (1,1) NOT NULL
, RecordId bigint 
, EventTime datetime2(3) NOT NULL
, SQLProcessUtilization int NOT NULL
, SystemIdle int NOT NULL
, OtherUtilization int NOT NULL
)


-- reviewing the data
SELECT *
FROM dbo.T_RingBufferReadings 
ORDER BY EventTime DESC

If there are many records, to improve the performance, one can create also an index, which can include the reading points as well:

-- creating a unique index with an include 
CREATE UNIQUE NONCLUSTERED INDEX [UI_T_RingBufferReadings_EventTime] ON dbo.T_RingBufferReadings
(
	EventTime ASC,
    RecordId ASC
) INCLUDE (SQLProcessUtilization, SystemIdle, OtherUtilization)
GO

The above query based on the DMV becomes:

-- cpu utilization by SQL Server and other applications
DECLARE @ts_now bigint = (SELECT cpu_ticks/(cpu_ticks/ms_ticks)
        FROM sys.dm_os_sys_info); 

INSERT INTO dbo.T_RingBufferReadings
SELECT record_id
, DAT.EventTime
, DAT.SQLProcessUtilization 
, DAT.SystemIdle 
, 100 - (DAT.SystemIdle + DAT.SQLProcessUtilization) OtherUtilization
FROM ( 
	SELECT record.value('(./Record/@id)[1]', 'int') record_id
	, record.value('(./Record/SchedulerMonitorEvent/SystemHealth/SystemIdle)[1]', 'int') SystemIdle 
	, record.value('(./Record/SchedulerMonitorEvent/SystemHealth/ProcessUtilization)[1]', 'int') SQLProcessUtilization
	, EventTime 
	FROM ( 
		SELECT DATEADD(ms, -1 * (@ts_now - [timestamp]), GETDATE()) EventTime
		, [timestamp]
		, CONVERT(xml, record) AS [record] 
		FROM sys.dm_os_ring_buffers 
		WHERE ring_buffer_type = N'RING_BUFFER_SCHEDULER_MONITOR' 
		  AND record LIKE N'%<SystemHealth>%') AS x 
	) AS DAT
	LEFT JOIN dbo.T_RingBufferReadings RBR
	  ON DAT.record_id = RBR.Recordid 
WHERE RBR.Recordid IS NULL
ORDER BY DAT.record_id DESC;

Note:
A ServerName column can be added to the table if is needed to store the values for different SQL Servers. Then the LEFT JOIN has to consider the new added column. 
Either of the two queries can be used to display the data points within a chart via SSRS, Power BI or any reporting tool available. 

Happy coding!

References:
[1] Grant Fritchey (2014) SQL Server Query Performance Tuning: Troubleshoot and Optimize Query Performance in SQL Server 2014, 4th Ed.
[2] Sunil Agarwal et al (2005), Troubleshooting Performance Problems in SQL Server 2005, Source: TShootPerfProbs.docx
[3] Sunil Agarwal et al (2008), Troubleshooting Performance Problems in SQL Server 2008, Source: TShootPerfProbs2008.docx
[4] Microsoft SQL Docs (2018) Related Dynamic Management Views, Source
[5] Microsoft SQL Docs (2017) Use ring buffers to obtain health information about Always On availability groups, Source

🧭🪄☯Business Intelligence: SQL Server Reporting Services (The Good, the Bad and the Ugly)

SQL Server Reporting Services (SSRS) is the oldest solution from the modern Microsoft BI stack. Released as add-on to SQL Server 2000, it allows covering most of an organization's reporting requirements, either if we talk about tables, matrices or crosstab displays, raw data, aggregations, KPIs or visualizations like charts, gauges, sparklines, tree maps or sunbursts.

The Good: Once you have a SQL query based on any standard data sources (SQL Server, Oracle, SharePoint, OData, XML, etc.), it can be used in just a few minutes to create a report with the help of a wizard. Sure, adding the needed formatting, parameters, custom code, drilldown and drill-through functionality might take some effort, though in less than an hour you have a running report. The use of templates and a custom branding allows providing a common experience across the enterprise. 

The whole service is available once you have a SQL Server license, fact that makes from the SSRS a cost-effective tool. The shallow learning curve and the integration with SharePoint facilitates the development and consumption of reports.

With its pixel-accurate display of data, SSRS is ideal for printing business documents. This was probably one of the reasons why SSRS become with Microsoft Dynamics AX 2009 also the main reporting platform for the further versions. One can use an AX 2009 class as source for the report, or directly use the base tables, which can increase reports’ performance in the detriment of reengineering the logic from AX 2009. With a few exceptions in finance area the reporting logic is easy to build.  

With SQL Server 2016 it got a HTML5 rendering engine, while with SSRS 2017 it supports a responsive web design. The integration of the SSRS and Power BI environments has the chance to further extend the value provided by this powerful combination, however it depends also in which direction Microsoft will develop this idea.   

The Bad: One of the important downsides of SSRS is that it doesn’t allow custom authentication. Even if some examples exist on the Web, it’s hard to understand Microsoft’s stubbornness of not providing this by design. 

Because SSRS still uses an older MS Office driver, it allows exporting only 65536 records to Excel, fact that makes data consumption more complicated. In addition, the pixel-perfect isn’t that perfect, the introduction of empty columns when exporting to Excel, adds some unnecessary burden.

In total, the progress made by SSRS between the various releases is small when compared with the changes suffered by SQL Server. Even if the visualization capabilities cover most of the requests, it loses field when compared with Power BI and similar visualization tools. 

The Ugly: SSRS, as the typical BI developer knows it, is different than the architecture frameworks provided when working with Business Central, respectively Dynamics 365 and CRM. Even if there are maybe entitled reasons, Microsoft failed to unite the three architectures into a flexible solution. Almost all the examples available on the Web target CRM, and frankly it’s hard to understand that. It feels like Microsoft wants to sabotage their own product?! What’s hard to understand is that besides SSRS and Power BI Microsoft has several other reporting tools for Dynamics 365. Building reports for Business Central or Dynamics 365 requires certain skills, while the development time increased considerably, thus SSRS losing from the appeal it previously had, allowing other tools to join the landscape (e.g. electronic documents).

SSRS can’t be smoothly integrated with Office 365 Online, remaining mainly a solution for on-premise architectures.  This can become a bottleneck when the customers move to the cloud, the BI strategy needing to be eventually rethought as well. 

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🧭Business Intelligence: Cognos & SQL Server 2008 - The First Report (Test Drive)

Yesterday evening I installed on my computer the IBM Cognos Express (V9) software, the newest Cognos version, available with a trial period of 30 days. The first attempt to install it was not errorless though as I had to observe several attempts later when I got the same error, the error was not fatal. So, once the instalation complete, the Express Manager started, finding out that I have to install manually the Manager, Advisor, Reporter and Xcelerator - quite easy to do.

Now I was ready to test the tool and create several reports, for this needing to create first a data source - a connection to an existing database with several tables on which the reports will be based. SQL Server 2008's AdventureWorks database seemed to be adequate for this test, in plus I know there are many SQL Server professionals already using it for testing or tutorials.

Step 1: Creating the SQL Server account

Reporting tools need in general only read access to data sources and as a good practice to enforce security and address the special requirements the reports are coming with, so it makes sense to create a new User for this. Open Microsoft SQL Server Management Studio and from the root navigate to Security/New/Login…, this action brining Login – New window in which must be filled

a. the Login name (e.g. cognosuser)
b. the authentification – because Cognos doesn’t supports Windows-based authentication, choose SQL Server authentication, enter the Password and confirm it. By default the ‘Enforce password expiration’ is checked, though this option is not needed for the current requirement so unchek it.
c. Select the Default database, the database you’re intending to base your reports on (e.g. AdventureWorks)
d. Select the ‘Default Language’ (e.g. English)
Navigate to ‘Use Mapping’ tab and in ‘User mapped to this login’ choose the databases you would like to give access (e.g. AdventureWorks) and for each database selected you’ll have to select the schemas in scope (e.g. HumanResources, Person, Production, Purchasing and Sales), while in’Database role membership for’ select the db_datareader database level role name, then you can click ‘Ok’.

 
It’s always a good idea to test the new account before attempting to use it from an external application, this allows catching the eventual issues early in the process, saving your and others’ time!

Step 2: Creating a Data Source

Start the IBM Cognos Express Manager and from Data click on ‘Add…’ button, action that will bring the ‘Enter Data Source Information’ in which you’ll have to select the ‘Data Source Type’, in this case Microsoft SQL Server (SQL 2005 Native Client), fill the ‘Name’ (e.g. AdventureWorks), ‘Server Name’ (here comes your SQL Server name), ‘Database Name’ (e.g. AdventureWorks ), ‘User ID’ (e.g. cognosuser) and password (e.g. something you must guess). As can be seen from the below image, there is also a Databae Object control, which will be populated once you entered the before mentioned information and clicked on ‘Retrieve Database Objects’ button. Select one of the database objects (e.g. AdventureWorks ) and click ‘Ok’, Cognos creating the Data (Source) in the background.

 
Step 3: Creating a Report

Instead of using Report Studio, the standard tool for designing reports, for simple reports or queries could be used instead the Query Studio, an easy-to-use authoring tool, the creation of a report resuming to a simple drag and drop. For this you’ll have to open the Query Studio from the Launch item found on the top menu, this action opening a new browser window, in a next step following to select the package (actually the data source) you want to use. In ‘Insert Data’ mode select a table from the list (e.g. Location) and drag and drop it into the right section, all table’s columns being shown together with a sample set of data.

You could double click on each column and give it a meaningful name – is a good practice to separate the words with spaces though not really necessarily. By clicking on report’s Title you could change its actual value and add a Subtitle if necessary. In ‘Change Layout’ you could change report’s layout by applying different Font, Border and Conditional Styles, much like in Excel, show row numbers by clicking the ‘Show row numbers’ from Change Layout/Set Web Page Size, etc. Save the report once you’ve done the changes, the report will look something like the one from the below image:
Step 4: Running the Report

From ‘Run Report’ Menu item you could choose to run the report mainly in three modes – ‘Run with All Data’, ‘Preview with Limited Data’ or ‘Preview with No Data’. Additionally you can export the report to PDF (Portable Document Format), several versions of Excel (2000, 2002 and 2007), CSV (Comma Separated Values) and XML (eXtensible Markup Language).

Happy coding!

🛢DBMS: Extensible Markup Language (Definitions)

"A standard for a markup language, similar to HTML, that allows tags to be defined to describe any kind of data you have, making it very popular as a format for data feeds." (Mike Moran & Bill Hunt , "Search Engine Marketing, Inc", 2005)

"Facilitates the assignment of meaningful structures and definitions of data and services for use by multiple systems. XML simplifies the ability to transmit and share data." (Jill Dyché & Evan Levy, "Customer Data Integration: Reaching a Single Version of the Truth", 2006)

"Simple and flexible text format used to represent data. XML was designed by the World Wide Web Consortium (W3C)." (Sara Morganand & Tobias Thernstrom , "MCITP Self-Paced Training Kit : Designing and Optimizing Data Access by Using Microsoft SQL Server 2005 - Exam 70-442", 2007)

"separates content from format, thus letting the browser decide how and where content gets displayed. XML is not a language, but a system for defining other languages so that they understand their vocabulary." (Craig F Smith & H Peter Alesso, "Thinking on the Web: Berners-Lee, Gödel and Turing", 2008)

"A platform-independent markup language for specifying the structure of data in a text document used for both data storage and the transfer of data." (Jan L Harrington, "Relational Database Design and Implementation" 3rd Ed., 2009)

"A way of representing data and data relationships in text files, typically for data exchange between software of different types." (Jan L Harrington, "SQL Clearly Explained" 3rd Ed. , 2010)

"A metalanguage used to represent and manipulate data elements. Unlike other markup languages, XML permits the manipulation of a document’s data elements. XML is designed to facilitate the exchange of structured documents such as orders and invoices over the Internet." (Carlos Coronel et al, "Database Systems: Design, Implementation, and Management" 9th Ed., 2011)

"A specification for creating text files that contain hierarchical data." (Rod Stephens, "Start Here!™ Fundamentals of Microsoft® .NET Programming", 2011)

"Has been created to overcome some difficulties proper to HTML (Hypertext Markup Language) that – developed as a means for instructing the Web browsers how to display a given Web page – is a ‘presentation-oriented’ markup tool. XML is called ‘extensible’ because, at the difference of HTML, is not characterized by a fixed format, but it lets the user design its own customized markup languages (using, e.g., a specific DTD, Document Type Description) for limitless different types of documents; XML is then a ‘content-oriented’ markup tool." (Gian P Zarri, "RDF and OWL for Knowledge Management", 2011)

"A set of rules for encoding documents electronically. XML was chosen as the standard message format because of its widespread use and open source development efforts." (Mike Harwood, "Internet Security: How to Defend Against Attackers on the Web" 2nd Ed., 2015)

"A standard metalanguage for defining markup languages that is based on Standard Generalized Markup Language (SGML)." (Sybase, "Open Server Server-Library/C Reference Manual", 2019)

"Extensible markup language (XML) is a simple, very flexible text format derived from SGML (standard generalized markup language). While XML was originally designed to meet the challenges of large-scale electronic publishing, it plays an increasingly significant role in the exchange of a wide variety of data on the web." (Kamalendu Pal, "Integrating Heterogeneous Enterprise Data Using Ontology in Supply Chain Management", 2019)

"A universal markup language for text and data, using nested tags to add structure and meta-information to the content." (Daniel Leuck et al, "Learning Java" 5th Ed., 2020)

"A 'best practices' subset of SGML that has been designed by the Worldwide Web Consortium (W3C) for use on the Internet." (Microfocus)

"A notation in which you describe the structure of information in a text document by enclosing information in user-defined tags that define the syntactic elements. A flexible way to create common information formats and share both the format and the data on the World Wide Web, intranets, and elsewhere. J2EE deployment descriptors are expressed in XML." (Microfocus)

W3: Resource Description Framework (Definitions)

"A framework for constructing logical languages that can work together in the Semantic Web. A way of using XML for data rather than just documents." (Craig F Smith & H Peter Alesso, "Thinking on the Web: Berners-Lee, Gödel and Turing", 2008)

"An application of XML that enables the creation of rich, structured, machinereadable resource descriptions." (J P Getty Trust, "Introduction to Metadata" 2nd Ed., 2008)

"An example of ‘metadata’ language (metadata = data about data) used to describe generic ‘things’ (‘resources’, according to the RDF jargon) on the Web. An RDF document is a list of statements under the form of triples having the classical format: <object, property, value>, where the elements of the triples can be URIs (Universal Resource Identifiers), literals (mainly, free text) and variables. RDF statements are normally written into XML format (the so-called ‘RDF/XML syntax’)." (Gian P Zarri, "RDF and OWL for Knowledge Management", 2011)

"The basic technique for expressing knowledge on The Semantic Web." (DAMA International, "The DAMA Dictionary of Data Management", 2011)

"A graph model for describing formal Web resources and their metadata, to enable automatic processing of such descriptions." (Mahdi Gueffaz, "ScaleSem Approach to Check and to Query Semantic Graphs", 2015)

"Specified by W3C, is a conceptual data modeling framework. It is used to specify content over the World Wide Web, most commonly used by Semantic Web." (T R Gopalakrishnan Nair, "Intelligent Knowledge Systems", 2015)

"Resource Description Framework (RDF) is a framework for expressing information about resources. Resources can be anything, including documents, people, physical objects, and abstract concepts." (Fu Zhang & Haitao Cheng, "A Review of Answering Queries over Ontologies Based on Databases", 2016)

"Resource Description Framework (RDF) is a W3C (World Wide Web Consortium) recommendation which provides a generic mechanism for representing information about resources on the Web." (Hairong Wang et al, "Fuzzy Querying of RDF with Bipolar Preference Conditions", 2016)

"Resource Description Framework (RDF) is a W3C recommendation that provides a generic mechanism for giving machine readable semantics to resources. Resources can be anything we want to talk about on the Web, e.g., a single Web page, a person, a query, and so on." (Jingwei Cheng et al, "RDF Storage and Querying: A Literature Review", 2016)

"The Resource Description Framework (RDF) metamodel is a directed graph, so it identifies one node (the one from which the edge is pointing) as the subject of the triple, and the other node (the one to which the edge is pointing) as its object. The edge is referred to as the predicate of the triple." (Robert J Glushko, "The Discipline of Organizing: Professional Edition" 4th Ed., 2016)

"Resource description framework (RDF) is a family of world wide web consortium (W3C) specifications originally designed as a metadata data model." (Senthil K Narayanasamy & Dinakaran Muruganantham, "Effective Entity Linking and Disambiguation Algorithms for User-Generated Content (UGC)", 2018)

"A framework for representing information on the web." (Sybase, "Open Server Server-Library/C Reference Manual", 2019)

"Resource description framework (RDF) is a W3C (World Wide Web Consortium) recommendation which provides a generic mechanism for representing information about resources on the web." (Zongmin Ma & Li Yan, "Towards Massive RDF Storage in NoSQL Databases: A Survey", 2019)

"It is a language that allows to represent knowledge using triplets of the subject-predicate-object type." (Antonio Sarasa-Cabezuelo & José Luis Fernández-Vindel, "A Model for the Creation of Academic Activities Based on Visits", 2020)

"The RDF is a standard for representing knowledge on the web. It is primarily designed for building the semantic web and has been widely adopted in database and datamining communities. RDF models a fact as a triple which consists of a subject (s), a predicate (p), and an object (o)." (Kamalendu Pal, "Ontology-Assisted Enterprise Information Systems Integration in Manufacturing Supply Chain", 2020)

"It is a language that allows to represent knowledge using triplets of the subject-predicate-object type." (Antonio Sarasa-Cabezuelo, "Creation of Value-Added Services by Retrieving Information From Linked and Open Data Portals", 2021)

"Resource Description Framework, the native way of describing linked data. RDF is not exactly a data format; rather, there are a few equivalent formats in which RDF can be expressed, including an XML-based format. RDF data takes the form of ‘triples’ (each atomic piece of data has three parts, namely a subject, predicate and object), and can be stored in a specialised database called a triple store." ("Open Data Handbook")

💎SQL Reloaded: XML on SQL Server 2005

That's the work I did for a homework at school (still studying, hoping to finish my Masters degree). Sorry, I have only short comments for it, hopefully will be helpful for somebody! /*creating a table for demonstration purposes ID - identity field Books - XML document where the tables are stored */ CREATE TABLE XMLBooks( ID int IDENTITY(1,1) PRIMARY KEY , Books XML) /*dropping the table */ --DROP TABLE XMLBooks /* inserting a record - an XML document containing one book*/ INSERT INTO XMLBooks VALUES ('<books> <book id="1" language="EN"> <title>Inside SQL Server 2005 Tools</title> <authors> <author>Michael Raheem</author> <author>Dima Sonkin</author> <author>Thierry D''Hers</author> <author>Kami LeMonds</author> </authors> <year>2006</year> <publisher>Addison Wesley</publisher> <price></price> <pages>816</pages> <isbn10>0-321-39796-7</isbn10> <isbn13>978-0-321-39796-6</isbn13> </book> </books>') /* inserting a record - an XML document containing three books*/ INSERT INTO XMLBooks VALUES ('<books> <book id="2" language="EN"> <title>Core C# and .NET</title> <authors> <author>Stephen C. Perry</author> </authors> <year>2005</year> <publisher>Prentice Hall</publisher> <price></price> <pages>1008</pages> <isbn10>0-13-147227-5</isbn10> <isbn13></isbn13> </book> <book id="3" language="EN"> <title> Microsoft SQL Server 2005</title> <authors> <author>Andrew J. Brust</author> <author>Stephen Forte</author> </authors> <year>2006</year> <publisher>Microsoft Press</publisher> <price></price> <pages>600</pages> <isbn10>0-7356-1923-9</isbn10> <isbn13>978-0-7356-1923-4</isbn13> </book> <book id="4" language="EN"> <title>MCAD/MCSD: Visual Basic .NET XML Web Services and Server Components Study Guide</title> <authors> <author>Pamela Fanstill</author> <author>Brian Reisman </author> <author>Mitch Ruebush</author> </authors> <year>2003</year> <publisher>Sybex</publisher> <price></price> <pages>598</pages> <isbn10>0-7821-4193-5</isbn10> <isbn13></isbn13> </book> </books>') /* a classical SELECT */ SELECT * FROM XMLBooks /* a first XML falvoured query*/ SELECT Books.query('/.') FROM XMLBooks /* selecting an element's content*/ SELECT Books.query('//book[@id=1]/title/text()') FROM XMLBooks /* selecting an element's content*/ SELECT Books.value('data(//book[@id=1]/title/)','varchar(250)') FROM XMLBooks 

  Msg 2256, Level 16, State 1, Line 2 XQuery [XMLBooks.Books.value()]: Syntax error near ')', expected a "node test". 

  /* selecting an element's content*/ SELECT Books.value('data((//book[@id=1]/title)[1])','varchar(250)') FROM XMLBooks /* selecting only the occurence*/ SELECT Books.value('data((//book[@id=1]/title)[1])','varchar(250)') FROM XMLBooks WHERE Books.exist('//book[@id=1]')=1 /* updating a node by inserting a new child after an existing one */ UPDATE XMLBooks SET Books.modify(' insert Jack Daniels after (//book[@id=1]//author)[1]') /* updating a node */ UPDATE XMLBooks SET Books.modify(' insert Jack Daniels before (//book[@id=1]//author)[1]') /* deleting a child */ UPDATE XMLBooks SET Books.modify(' delete //book[@id=1]//author[1]') /* modifying an attribute */ UPDATE XMLBooks SET Books.modify(' replace value of (//book/@id)[1] with "100"') /* deleting a record */ DELETE FROM XMLBooks WHERE Books.exist('//book[@id=1]')=1 SELECT Motocross.Team.query(‘.’) AS RESULT FROM @xmlvar.nodes(‘/Motocross/Team’) Motocross(Team) SELECT Book.Athors.query('/.') AS AuthorsList FROM XMLBooks.nodes('/books/book/authors') Book(Authors)

🌁Software Engineering: Simple Object Access Protocol (Definitions)

"An XML-based protocol for invoking remote procedures. SOAP has become one of the cornerstones of Web services, and has been accepted as a standard by all major vendors including Microsoft, SUN, IBM, and others." (Atul Apte, "Java™ Connector Architecture: Building Custom Connectors and Adapters", 2002)

"A standardized protocol used to call Internet-based services (Web services) by exchanging XML messages." (Johannes Link & Peter Fröhlich, "Unit Testing in Java", 2003)

"Designed by the World Wide Web Consortium (W3C), this transport protocol provides a standard way to send messages between applications using XML." (Sara Morganand & Tobias Thernstrom , "MCITP Self-Paced Training Kit : Designing and Optimizing Data Access by Using Microsoft SQL Server 2005 - Exam 70-442", 2007)

"is a protocol for exchange of information in a distributed environment. It is an XML based protocol consisting of three parts: an envelope (a framework for describing what is in a message and how to process it), a set of encoding rules (for expressing instances of application-defined datatypes), and a convention for representing remote procedure calls and responses." (Craig F Smith & H Peter Alesso, "Thinking on the Web: Berners-Lee, Gödel and Turing", 2008)

"A protocol for exchanging XML messages over a network. It defines the structure of the XML messages (the SOAP envelope), and a framework that defines how these messages should be processed by software." (Mark Olive, "SHARE: A European Healthgrid Roadmap", 2009)

"A wrapper specification from the World Wide Web Consortium (W3C) for requests for web services that facilitates interoperability between a broad mixture of programs and platforms." (DAMA International, "The DAMA Dictionary of Data Management", 2011)

"A protocol specification for exchanging structured information in a Web services implementation." (Craig S Mullins, "Database Administration", 2012)

"A protocol specification for exchanging data. Along with REST, it is used for storing and retrieving data in the Amazon storage cloud." (Marcia Kaufman et al, "Big Data For Dummies", 2013)

"A common protocol used to establish a session between a Web server and mobile app; it is stateless by design." (Mike Harwood, "Internet Security: How to Defend Against Attackers on the Web" 2nd Ed., 2015)

"A lightweight protocol for exchange of information in a decentralized, distributed environment." (Adam Gordon, "Official (ISC)2 Guide to the CISSP CBK" 4th Ed., 2015)

"A standard format in XML for sending data between a client and a Web service. The service's WSDL file specifies the format of the SOAP messages it expects and will return." (Microfocus)