Introduction to SEO - Search Engine Optimization

Refer SEO series (list of articles) here

One of the best things of writing a blog is that one constantly learns and upgrades his knowledge.
Knowledge also grows, when people share their experiences.

Today's article is an introduction to SEO (Search engine optimization). It will be the first of the many articles I intend to write on this topic as I learn more on SEO.

Also, I intend to use all of the best practices that I learn in this article (and obviously in the future).

So, what is SEO (search engine optimization)?
At its most basic, "SEO" means trying to get your site as high up as possible on search result pages.
This generally means more traffic to your site.
One can define it as a process of trying to make a website appear in a high position when users conduct a search with keywords.

In upcoming articles, I may go into more details, but to explain in basic terms:
Search engines have two major functions:

• Crawling and indexing documents, articles, images etc
• Return search results with max relevancy and importance (popular)

SEO techniques provide ways that search engines can crawl the site and the site comes up in the search results.

So, how do we go about it? As mentioned, this is an introductory article and we shall have more detailed articles in the future.

Keywords
One should be conscious of placing appropriate keywords throughout every aspect of his/her site:

• Titles
• Content
• URLs
• Images

Users search based on keywords, and hence keywords, if indexed by search engines, will help to increase a site's relevancy and popularity.
The title tag and page header are the two most important spots to put keywords.
Description meta tag gives the search engine a summary of what the page is all about.
Ensure title tag text also appears in the body of the page.

Note: Be judicious in your usage of keywords. If you overdo the number of keywords, you risk your site to be labelled as SPAM by the crawlers/spiders.
Will briefly touch more about this topic when we discuss on SPAM.

Internal Links:
Linking related pages within your site is an easy way to boost traffic to individual pages.
Links also make it easier for the crawlers to crawl through your page.
Make the anchor text search-engine-friendly -- keywords linking pages will add to the index and show up in users search results.

Sitemap:
Create a sitemap (a page listing and linking to all the other major pages on your site).
It makes it easier for spiders to search your site.

Learn more about sitemaps here

Avoid Flash
Avoid using Flash. Avoid Frames and AJAX.
However, if you do use, place text and links around it.

Images and the ALT tag
Crawlers/Spiders crawl though text data. They do not crawl within images (jpg, png etc).
Thus, one needs to ensure that if images are used, the ALT text has a keywords in the description.
This is something that I need to start doing and I will report back on the improvements.

Content
It will help if the content is updated frequently.

Role of Social media
Social media plays an important role in SEO. If there are popular websites which have links to your sites, there is an increased probability for users to click and get redirected to your site.

Kindly note that I am not suggesting that one should SPAM other sites and put in their website links. There is a mutual understanding to help each other and have links to popular sites (as well as have links to your site within the popular sites).

I have pages that I don't want to be crawled.
If you have a specific requirement to avoid crawling of specific pages (typically some internal only pages), one can instruct crawlers/spiders to NOT crawl those URLs (via robots.txt).

• When a search engine visits a site, the robots.txt located in the root directory is the first file crawled.
• The robots.txt file is then parsed, and will instruct the robot as to which pages are not to be crawled.
• This file may be cached, and hence you sometime may see some pages crawled that you did not want to be crawled.
• Additionally, a page can be explicitly excluded from a search engine's database by using a meta tag specific to robots.

SEO Techniques:We will try to give a brief introduction to SPAMming via SEO.
Note that the below is just an introduction and we will have follow up articles on the same soon.

SEO techniques can broadly be classified into two types:

• White hat
• Black hat

An SEO technique is considered white hat if it conforms to the search engines' guidelines and involves no deception.
The techniques mentioned above are part of white hat technique.

Black hat SEO attempts to improve rankings in ways that are disapproved of by the search engines, or involve deception like:

• Hidden text (either as text colored similar to the background or invisible div tag)
• Providing different page for user based searches and machine based searches (Cloaking)
• SPAMdexing

Cloaking:

• Cloaking is a search engine optimization (SEO) technique in which the content presented to the search engine spider is different from that presented to the user's browser.
• This is done by delivering content based on the IP addresses or the User-Agent HTTP header of the user requesting the page.
• When a user is identified as a search engine spider, a server-side script delivers a different version of the web page
• The purpose of cloaking is sometimes to deceive search engines so they display the page when it would not otherwise be displayed
• They try to trick search engines into giving the relevant site a higher ranking.

SPAMdexing

• SPAMdexing is the deliberate manipulation of search engine indexes. Some phrases or keywords are repeated deliberately to manipulate the relevance of the page.
• SPAMdexing techiniques are broadly classified into

• Content SPAM

• Keyword stuffing involves the calculated placement of keywords within a page to raise the keyword count and make a page appear to be relevant for a web crawler.
• Doorway pages are low-quality web pages created with very little content, but are instead stuffed with very similar keywords and phrases. They are designed to rank highly within the search results.

• Link SPAM

• Link spam takes advantage of link-based ranking algorithms, which gives websites higher rankings
• A spammer may create multiple web sites at different domain names that all link to each other, such as fake blogs (known as spam blogs).

Refer SEO series (list of articles) here

Seven basic tools of Quality

Refer to master index list for project management articles.

This is child article describing the tools of Quality Control. Refer to the parent article here

Note: The images in this post have been taken from the internet.

The seven basic tools of Quality are briefly described below:

Fishbone Diagram (or Cause–and–Effect Diagram or Ishikawa Diagram)

The fish bone diagram identifies many possible causes for an effect or problem
It illustrates how various factors may be linked to potential problems or effects.
It immediately sorts ideas into useful categories.

Control Charts
Its purpose is to determine whether a process is stable or has predictable performance.
These charts gather data to illustrate process behavior in a variation situation over a period of time.
Control charts can be used to assess whether the application of process changes resulted in the desired improvements or not.

They can be used for both project and product life cycle processes. Can be used to monitor any type of output variable.

Flow Chart
We may have used flowcharts at some point in time. Its helps to analyze how problems occur by graphically representing a process.

Histogram
A histogram is a bar chart showing distribution of variables. Each column represents a problem. Height represents the relative frequency of the characteristic.
Histograms helps to identify the cause of the problem in a process by the shape and width of the distribution.

Pareto Chart
Pareto chart is a histogram (bar chart) that shows number of defects against a type of cause. This technique is used to identify and evaluate non-comformities.
Pareto charts are conceptually related to Pareto's Law (commonly known as as the 80/20 principle which states that 80 percent of the problems are due to 20 percent of the causes)

Run chart
Line chart that shows history and pattern of variation. They show trends in a process over time, improvements/declines in a process over time.
Used to forecast future outcomes based on historical results.

Scatter diagram
Shows the pattern of relationships between two variables.
Dependent variables versus independent variables are plotted. The closer the points to the diagonal line, the more closely they are related.

Statistical Sampling
A small quantity of product is tested for quality. If the product passes the quality test, the lot is accepted.


Note: The images in this post have been taken from the internet.

Quality management

Refer to master index list for project management articles.

We shall discuss one of the knowledge areas viz. Quality management.

"Do the right thing right the first time."

Quality management consists of:

• Quality Planning
• Perform Quality Assurance
• Perform Quality control

Quality Planning:

Quality planning is critical since it identifies quality standards for a project.
The basic premise of Quality planning is that the cost of avoiding mistakes is less than the cost of correcting them.

Plan, Do, Check and Act (PDCA) model can be followed for continuous validations of processes and their efficiency in producing the expected results.

Input:
Inputs to Quality planning are:

Project Scope Statement
Constraints, assumptions, list of deliverables, acceptance criteria etc are all part of the project scope statement.

Stakeholders assessment
Lists down the stakeholders of the project.

Baseline documents:
Cost performance baseline documents the accepted time phase used to measure cost performance.
Schedule baseline documents the accepted schedule (for performance) with start and end dates.

Risks
Risks are documented and contains information that may impact quality requirements.

Output:
Quality planning results in the following output:

Quality management plan
Addresses quality control, assurance and continuous quality improvement initiatives.
This plan is built on the projects requirements and describes how quality assurance will be performed within the project.

Quality metrics
Includes defect density, failure rate, availability, reliability and test coverage.

Quality checklists
Documents the set of required steps to be performed (ensure consistency in tasks).

Process improvement plan
Identify and eliminate non value adding activities. Helps in improving processes.


Quality Assurance:
Quality assurance is the application of planned, systematic quality activities to ensure that the project will employ all processes needed to meet requirements.
Audits are performed to identify if the project activities comply with the organizational and project policies, processes and procedures. It also confirms the implementation of approved change requests, corrective actions defect repairs and preventative actions.

Inputs:
Quality management plan (already described above)
Process improvement plan (already described above)
Quality metrics (already described above)

Outputs:
Change request document
Documents the changes made to improve the quality of the project (technical and organizational).

Project management plan updates
Any update to Quality management plan will require an update to the project management plan.

Other documents
Quality audit reports, training plans and process documents are the other documents that are created.

Quality Control

Quality control involves monitoring specific project results to determine whether they comply with relevant quality standards.

Inputs:
Project management plan
Quality metrics (already described above)
Organizational processes document which includes quality standards and policies, work guidelines, defect reporting procedures and communication policies.
Approved change requests document which includes list of modifications (revised work methods and revised schedule).
Deliverable document

Note: Basic tools of Quality will be documented in a separate article.

Output:
Quality Control measurements represent the results of Quality control activites that are used to analyze the quality standards.
Validated changes document lists the items that were corrected. The corrected items are re-inspected and accepted or rejected.
Completed checklists and lessons learnt 

Validated deliverables
Project management plan updates
Any update to Quality management plan (as a result of Quality control process) will require an update to the project management plan.

Project and Project management (Introduction)

Refer to master index list for project management articles.

While we have spoken about Agile and Scrum in earlier articles, I thought it would help to start a little earlier (defining project and its characteristics).

What is a Project?
A temporary endeavor undertaken to create a unique product, service or result.

When we mention temporary, we do undertsand that every project has a definite beginning and end (does not imply short duration though). Howvever, it's not an ongoing effort.
Once the project objectives are met, the project is terminated (there is no need for a project anymore).

Constraints of Project management:

Constraints of project management is best see via the Triple Constraint Theorem.

Balancing scope, time and cost within the frame work of quality and meeting customer expectations.

You could also look at an alternate way of making a balanced project in the following way:

Limiting scope within the time and cost constraints and quality framework.

Project management knowledge areas
There are multiple project management knowledge areas. I will try to write an article on each one of them separately in the future.

Let me give a brief on the knowledge areas:

Scope management:
Includes all the work required to complete a project successfully. Consists of scope planning, definition, verification and control.

Cost management:
Ensure project is completed within the budget. Consists of estimation, budgeting and cost control.

Time management:
Ensure timely completion of the project. Consists of activity definition, resource and duration estimation, schedule development and control.

Communication management:
Consists of communication planning, report performance and manage stakeholders.

Quality management:
Consists of Quality planning, assurance and control.

HR management:
Human resource planning and develop/manage project teams are its main constituents.

Risk management:
Aspects of projects can put a project delivery under risk. Risk identification,qualitative and quantitative analysis along with response planning and monitoring are the important processes.

Procurement management:
If contracts are needed as part of the project, then we need to plan contracts and will involve lots of administrations.

Project Integration management:
Integration management consists of processes that ensure that various elements of a project are properly coordinated.

Project management

This page lists all the articles in this blog which are related to project management.
As more articles are published, we will update this page accordingly.

• Project and Project management (Introduction)
• Quality management
• Seven tools of Quality management 
• Benefits of being agile for an organization
• Basics of agile methodology
• Agile principles and values
• Introduction to Scrum
• Introduction to Kanban

Agile - Principles and values

One of the most important things to remember is that AGILE is NOT
- A set of tools
- Process
- Methodology

AGILE is a set of values.

The Agile Manifesto as per wikipedia reads, in its entirety, as follows:

We are uncovering better ways of developing software by doing it and helping others do it. Through this work we have come to value:

• Individuals and interactions over Processes and tools
• Working software over Comprehensive documentation
• Customer collaboration over Contract negotiation
• Responding to change over Following a plan

That is, while there is value in the items on the right, we value the items on the left more.
As we had mentioned in our previous agile article, continuous feedback is very important.
Point 1 above is on similar lines where continuous feedback is more important when we mentioned "individuals and interactions".

Working software will definitely get more value over documentation, but it does not imply that documentation is not at all needed.

With time a customers needs can change. Even due to marketing dynamics, needs can change. Hence, customer collaboration and continuous checks on delivery will help to deliver a model which the customer can appreciate.

As mentioned, market dynamics and conditions may make the customer change his requirements. Incremental reviews and phase wise delivery and continuous feedback and collaboration will help us deliver a product close to customer's needs (at that point in time).

The Agile Manifesto, as per wikipedia, is based on twelve principles:

• Customer satisfaction by rapid delivery of useful software

• Work closely with the customer and provide timely incremental delivery of the product
• Incremental reviews for customer feedback
• Capture acceptance criteria on each discussion
• Prioritize the pending requirements
• Conduct surveys to find the satisfaction level of the customers

• Welcome changing requirements, even late in development

• It is widely accepted that customer needs can change with time due to market dynamics
• One needs to embrace this change to provide value to the customer
• Evolve a process that accepts these changes
• Changes need to be prioritized with existing requirements

• Working software is delivered frequently (weeks rather than months)

• Frequent incremental delivery of software.
• These are sprint reviews (may be in a couple of weeks and not months).
• Automated, performance and load testing plays an important part in testing such small delivery cycles continuously.

• Close, daily cooperation between business people and developers

• In non-agile models, business and development teams rarely interact. This could lead to a delivery of a product that may not adhere to the customers need at that point in time.
• There should be frequent interaction between business and development teams.
• Development team benefits from knowing the business perspective (about the function of the software)
• Business teams gets insight into development details that they may not have an idea about when they conceive the product needs.

• Projects are built around motivated individuals, who should be trusted

• Motivated employees need to be encouraged and involved in the product.
• Employees feel empowered and result in higher output and better product

• Face-to-face conversation is the best form of communication (co-location)

• Lot has already been mentioned about communication, hence not delving much into this point.

• Working software is the principal measure of progress

• Self explanatory - a working software is a measure of progress.
• In waterfall, there is no working software at any point in time (in the schedule) except at the end. Thus, from customers perspective, there has been no progress to see.
• For every incremental release, there should be a working demo which should go through automated set of testing.
• Customer feedback is gathered at the end of the demo and any new changes need to be prioritized and embedded for the next subsequent releases.

• Sustainable development, able to maintain a constant pace

• Pretty much self explanatory, constant pace need to be maintained.
• However, need to ensure that members of teams do not work crazy hours/weekends (maintain 40 hours a week)

• Continuous attention to technical excellence and good design

• I guess this is a no brainer. Team members need to have the the technical expertise to deliver a quality product.
• There should also be a focus to continuously learn and improve upon coding standards, design, integration and testing.

• Simplicity—the art of maximizing the amount of work not done—is essential

• Reduce non value added work of team members.
• Simplify process of deployment or remove extra features etc

• Self-organizing teams

• As the product evolves, there is a need to change the architecture, requirements, design etc. Team members must be involved in decision making leading to greater ownership and responsibility.
• This is not easy and requires a lot of team work and an open culture that promotes team based rewards etc

• Regular adaptation to changing circumstances

• Periodically, there should be an introspection on how to become more effective and be able to adapt to changing demands and requirements.
• Self organizing teams are the key to real improvement.
• There should be a commitment to adapt and improve with every iteration over a period of time.

Some 12C Features

Will try to describe some of the 12C features and will keep editing this post.

Note:

• If you want to install Oracle 12 on Windows 7, refer the steps here 
• To troubleshoot invalid common user or role name after installation, go here

Feature List

 Identity Columns:

• Also known as auto-number column. This implies that the data in the column should increase when data is inserted).
• Read article on the same here.

 Invisible Columns:

• Columns can be made invisible
• It gives one the ability to introduce a change while minimizing any negative side effects of that change.
• Read article on the same here 

With Clause:

• Instead of using a stored PL/SQL function, we can include the body of the function in the SQL query
• Read article on the same here 

 Truncate statements with the cascade option

• We could not truncate table with foreign key constraints.
• Now in 12c, one can execute the truncate table command with the cascade option (to cascade through the child tables).
• Note: You would need to create the foreign key with the "on delete cascade" option

Columns can have a default value in place of NULL

• You can define a column to have a default value when NULL is inserted
• e.g. create table ......  product_id NUMBER ON NULL 0,.....
• So if one explicity inserts NULL, it will be populated by value 0

Multiple Index - same columns

• You can create multiple indexes (different types) on a same set of columns.
• Assume you need to change from B*tree to Bitmap or vice versa.
• You need not drop the index.
• Just make the first index invisible and make a new index.
• Conditions:
• Different types of indexes
• Different uniqueness
• Different partitions are used

 

12 C Feature - WITH Clause

Note: Index article on some 12c features can be seen here

The with clause is more efficient to use than sub queries.
Instead of using a stored PL/SQL function, we can include the body of the function in the SQL query.
Benefit is that it will run faster than the call of a function by the same statement.

This can be better explained with an example.
Lets create a table with some test data.

Look at the usage of the function using with - in the body of the query.

The function in the with clause over-rides the function created at schema level. In below screenshot, you can see the schema level function returning SYSDATE+1 and the with clause function returning SYSDATE+2. Check the output - its SYSDATE+2.

Note: You need to put in a slash (/) at the end else SQLPLUS waits for more input (refer lines 9-12 in the snapshot waiting when ENTER key was pressed).

12 C Feature - Invisible Columns

Note: Index article on some 12c features can be seen here

The name is self explanatory.
Invisible columns means just that -- columns that are invisible.
It gives one the ability to introduce a change while minimizing any negative side effects of that change.

So, in a table, if we add a column, it will show up in a "select *" query.
All the "insert into <table> values ...." queries will break.

When you add an invisible column, you won't be able to see it even when you execute a "DESC" or when you run a "select *" query.
The "insert into <table> values ...." queries will not break.
However, you will able to see it if you specifically query for it by name.

Lets have a look at an example.
We have a table "TEST_IDENTITY" which we had used to test the identity column. Refer article on identity column

Lets add an invisible column to it.
The command will be:

ALTER TABLE <TABLE_NAME> ADD (<COLUMN_NAME> <TYPE> INVISIBLE);

As you can see below, I added a column name as INVISIBLE and it does not show up in DESC command.
It does not show up in "select *" and has no impact on the "insert into <TABLE_NAME>" as well.

But you can insert data into it and also do a select by calling it explicitly.

You can make the column visible by running the following alter command:
ALTER TABLE <TABLE_NAME> MODIFY <INVISIBLE_COLUMN_NAME> VISIBLE;

Some questions that may help:

How to know a table exists with an invisible column?

Run a query on USER_TAB_COLS
SELECT COLUMN_NAME, HIDDEN_COLUMN FROM USER_TAB_COLS WHERE TABLE_NAME = '<TABLE_NAME>';

What if I create an invisible column as NOT NULL?
INSERT will fail. You need to create with DEFAULT option or use a trigger to populate on INSERT.

Is there any massive advantage of this feature?
Its a feature which could be used but not any with massive advantage. it could create problems for some applications when made visible, but if you have coded with proper INSERTs/SELECTs (mentioning columns), it won't harm your application.

12 C Feature - Identity Columns

Note: Index article on some 12c features can be seen here 
 
Identity Columns

What is an Identity column?
This is also known as auto-number column. This implies that the data in the column should increase when data is inserted.

In previous version of Oracle 12c, this was accomplished in the one of the following two ways:

• Create a sequence
• Insert the sequence.nextval in the INSERT STATEMENT

OR

• Create a sequence
• Create a Trigger "BEFORE INSERT ON TABLE"

Trigger created:
CREATE OR REPLACE TRIGGER test_trg
BEFORE INSERT ON testseq
FOR EACH ROW
BEGIN
 SELECT test_seq.nextval INTO :new.id FROM dual;
END;


In Oracle 12c, the same thing can be achieved without the use of sequence and triggers in two ways:

Column default clause (with sequences)

Create a sequence and use it as part of the table creation.
One can specify sequences (NEXTVAL or CURRVAL) as default column values. When a new row is inserted into the table, the sequence value is automatically inserted.

Look at the screen shot below where I have created a sequence and a table.
You can see that we can also put in out own data (data with value like 100 in the example or null) and it overrides the value from the sequence.

I have made the column not null, and we can see on inserting null, it throws an error.

Using GENERATED as IDENTITY in Column definition:

Here I will show example of identity columns which can be specified in the CREATE TABLE and ALTER TABLE statements.

Create a table using the IDENTITY clause.

Create table test_identity
(
  id NUMBER GENERATED as IDENTITY,
  name VARCHAR2(100)
);

When you do a describe, you shall see that the column is by default NOT NULL;

Running a query on DBA_SEQUENCES shows a new SEQUENCE created by the name ISEQ$$_92446 (system-generated name in the format ISEQ$$_<objectID> where objectID is the object id of the table)

Also note that you cannot alter an existing non-identity column to become an identity column.

Difference between "Column default clause" and "Using GENERATED as IDENTITY"

ORA-65096: invalid common user or role name in Oracle 12c

Note: Index article on some 12c features can be seen here 

ORA-65096: invalid common user or role name in Oracle 12c

This error usually occurs due to we are trying to create user ( common user ) under root container.

In oracle 12c there are two type of users: common and local.

Common users belong to CBD’s as well as current and future PDB’s.

The user can perform operation in Container or Pluggable according to Privileges assigned


Local users is purely database that belongs to only single PDB. This user may have administrative privileges but this only belongs to that PDB.

Refer screen shots below on creation of user's in both containers.

Note that  users in CBD$ROOT container must start with C##

For the local user:

Please do note that you will need to make an entry in the tnsnames.ora for the container (with the service name). There will already be an entry for the CBD$ROOT container by default. You can copy the same and change the name and service name.

Do "grant create session to test;"
Since this is my test schema, I have also run "Grant UNLIMITED TABLESPACE to TEST;" (else you may encounter ORA-01950: no privileges on tablespace 'USERS')

You can then connect to test using "conn test/test@pdborcl;"

Installing Oracle 12c Database on Windows 7 (64 bit)

Note: Index article on some 12c features can be seen here 


Kindly peruse through the below steps (detailed) for installing Oracle 12 c DB on Windows 7 (64 bit):

Step 1.
Download the required binaries from Oracle website

Step 2.
Once downloaded, unzip the files into one folder. I created a folder "Oracle 12c" in D: and another folder in it called "database"

So my folder structure was D:\Oracle12c\database

Step 3.
Click on setup.exe

Step 4.
You could put your email address and request for support (if needed). I have not selected this option for this install.

Step 5.
I chose to skip software updates

Step 6.
Select "create and configure a database"

Step 7.
I have chosen "server class"

Step 8.
Type of DB installation - I chose Single

Step 9.
Choose Typical install and in the Next screen create a new Windows user (you can use an existing one if you want)

Step 10.
I changed the global database name to "orcl" and created a Pluggable DB "pdborcl"

Step 11.
After verification, click on install and await for the installation to complete.

Step 12.

Open a command prompt and test your install

Note: If you try to create a schema under root container, you may encounter ORA-65096 error.
For resolution of the same, have a look at the article here.