I've started blogging 4 months back. Just submitting my articles in it. The url was wordpress default permalink.

example: http://www.domain.com/?p=N

Later on I was advised that I should make the url as www.domain.com/%category%/%postname%/

So I changed the url format. It's almost 20 days that I've changed the url format. But till now the new format has not been considered by the search engines.

I've even activated the permalink redirection plugin. Even then the search engine shows the same old url format.

Any help would be appreciated.

Have patience and wait the 4 to 6 months for it all to be reindexed.

Using a 301 from old format to new could reduce it to around 3 months

if the old format returns a 200 response it will never happen BTW

Does it cause any harm? ...I'm ready to wait for that certain period.

Guess it depends what "any harm" means. You probably changed the URL structure for SEO gain, right? Because http://www.example.com/category/the-...blog-post.html isn't exactly user friendly, right? The user gets one word wrong and 404! In 3 to 6 months you'll see that small SEO gain, but until then, you'll loose the position you're ranking now.

Are you really only putting each post in one category? Does it just pick the first? How does that work?

I'm categorizing the posts. Say all software related posts are placed in "Software" category and the music and movie related posts are placed in "Entertainment" category.

So if you wrote a post about software that turns DVD formated movies into Video CD, wouldn't that belong in both the software and movie category? How does the permalink structure handle this scenario?

I'll do surely let you know when i submit that sort of post.

So you've never ever posted anything that belongs in two categories? Remember as stuff gets pushed off your front page visitors have three ways to find it. They can keep hitting "previous page" until they find what they want, they can use the site search if you provide one, and they can use categories. I think a lot of users like the last option best - I know I do. When I find a blog worth reading, I'll go through everything they've had to say about topics that interest me.

What I'm trying to say is if you use categories a certain way, it can help your natural traffic. But since things are already all shook up about your URL change, this is probably the best time to consider that, and how putting category in the URL will mix with everything.

If you look at my blog as an example and take posts tagged as about Nietzsche, one of them is also tagged with "free will" and "perception" because it's about Nietzsche's theories on these things. If somebody finds me searching for info about the German philosopher, likes what I wrote, and then follows the "consciousness" category, they'll find posts on the book Be Here Now by Ram Dass, Monkeys Learning to Use Sticks as Tools, and the science of "Out of Sight Out of Mind". Multiple categories help keep readers interested by helping them discover other content of yours.