Performance: Array or Database approach?

[searain]

For example, I have a page to display one product. A sql select for this product is executed.

But I also need to know how many products in this group, and in the order of the name, which product is the previous product which is the next product of the current product. So a sql to select all the products in this group is needed.

Instead of doing two sqls. I just one sql, select all the products in this group.

And save all the products information in arraies. And then display the product I want to display by calling the elment of the arraies.

Which is performacing better?

1) sql for the product to get the display information, and sql for the group to get the group count, and product id for the previous product and next product?

2) or one sql get all the products and save all the information in arraies. But pick up the index to display certain product (element of the arraies)?

Second approach saved on sql but use arraies to save a lot of information which is not used. Is this a bad practice?

[PyroX]

I would rather see 10 small queries than 1 huge one on my network.

As far as I know, the connection is not closed until the script exits, or longer if you use persistent connections.

So you could run 1/2 as many queries as you have rows and still be better off.

For example, if I had a table with 100 rows, I could get all 100 rows, or query 50 times for 1 row, and be about the same in efficiency.

Why? Because to query, php transmits and then obtains the response. 100 rows in the response, or 50 tiny responses, with 50 tiny requests.

On the other hand, loading up an array with too much data is not good.

Any way I look at this, I say you should use multiple queries.