I am creating a php script with simple coding. I don't have much knowledge about caching. But have heard that there are object caching, Database Caching which will improve load time.
e.g., I have a sample php query, how can I enable database caching and please also tell me some basics about object caching.
$test="
SELECT *,
Sum(sellprice*quantity) + tips AS amount,
receiptdetails.name AS personname
FROM cart,
cartproduct,
receiptdetails,
receipt,
product
WHERE cart.ID = cartproduct.cartid
AND receiptdetails.cartid = cart.ID
AND receipt.cartid = cart.ID
AND product.ID = cartproduct.productid
GROUP BY cart.ID
";
The most popular way is to use Memcached for caching. Basically it is just a key-value storage engine that cache values in RAM. Your application can make use of it to cache values to reduce the needs for querying DB every time.
You can take a look at the PHP's Memcached extension on how to use PHP with Memcached.