I was wondering what is the reason behind pagination? Is it used because it lessens the burden on the servers since we would technically limit the amount of rows returned per page?
I wanted to do something without pagination but given that I am new to this (I am an amateur) started wondering if its OK technically or not.
There are a number of reasons for having pagination, reducing server load is just one. However, Stephen Orr raises a valid point - you still need to find the amount of data first. You have to make sure that that query is quick and doesn't unduly load your server.
Other reasons include:
In both of these cases you don't want to make the user wait - either for data they aren't going to view, or for all the data when they could be getting one with processing some of it.
It varies depending on implementation.
It will speed up rendering of a page, but it won't necessarily reduce the load on the server. Most naive pagination algorithms need to perform a query first to decide how many pages there should be, then query again to get the "paged" result set.
The most value you gain from pagination is enhancing the speed of your application by:
1 - Limiting data transmitted between the client and the server. There is no point to read 1000000 customers if the user is looking for 10 of them.
2- Speeding the query performance significantly by retrieving only rows that can fit in a user's view. There is no point to read 1000000 customers if the user will look at the first 10 customers.
3 - Pagination helps by providing more fresh data. If your application shows many data rows and your application domain requires lots of update to data rows in the displayed table, chances are that by the time you go to page 20 of the list of pages, the data on some of the rows would have been changed. Think of an application that reads stock prices or available rooms in a hotel. Retrieving old data and placing it on the client is of no use.
Pagination is one strategy that in combination with filtering and your understanding of how the end user needs from the particular scenario (which is expected to lead to a good design to serve this need) will greatly enhance the application specially when several users are hitting the database concurrently.
Pagination is not always trivial to program. In some cases it is simple but it is sometimes very complex to write so that the SQL query executes without performing a full table scan. This of course depends on your indexes, filter condition and your Where statement.
Pagination, to my mind, is the mother of all premature optimisations. It is absolutely ok to write your site without pagination.
If you find, after release, that you are loading too much data in one call, or that your users are having to wait for information that they do want because it's busy loading data they don't want, go ahead and write an Ajax solution which only loads the page as people scroll down (see: Twitter, Tumblr, Google image search).
Edit: The second paragraph above was written with the assumption that a common response would be "but if you know you are going to paginate at some point, you may as well do it early, rather than waste time developing something you are going to throw away."
As well as being the mother of all premature optimisations, I think that pagination is a UX nightmare and that there are better solutions which wouldn't require much extra development on top of the complete page.
Despite the number of downvotes, I am leaving this answer here because I stand by the sentiment, even though it may not have been my best writing.
