Page 255 - Open Soource Technologies 304.indd

Unit 10: Database

For example, this stores a list of available databases in $dbs: Notes
$dbs = $db->getListOf(“databases”);

10.4.7 Transactions

Some RDBMSs support transactions, in which a series of database changes can be committed (all
applied at once) or rolled back (discarded, with the changes not applied to the database). For
example, when a bank handles a money transfer, the withdrawal from one account and deposit
into another must happen together neither should happen without the other, and there should
be no time between the two actions. PEAR DB offers the commit ( ) and rollback( ) methods to
help with transactions:

$res = $db->commit( );
$res = $db->rollback( );

If you call commit( ) or rollback( ) on a database that does not support transactions, the methods
return DB_ERROR.

Be sure to check your underlying database product to ensure that it supports
transactions.

Success story on big fish games triples database

ig Fish Games is a global leader in the online games industry and distributes
more games worldwide than any other online site. Within three years of its debut,
BBigFishGames.com rocketed into the Top 10 game portals on the Web and now serves
millions of downloads everyday.
Their Business Challenge
BigFishGames.com is a fast-growing website with over 25 million unique customer accounts
and over 2.5 million visitors per month. In addition to the English site, Big Fish Games also
offers international game portals in Japanese, German, French and Spanish. Their ever-
growing user base is a huge boost to their business, but it also raises big challenges around
IT capacity planning. To ensure the highest quality game experience, Big Fish Games has
to accurately predict demand and increase bandwidth at the right time to keep a balance
between over-utilizing the system, introducing delays and a bad user experience, and under-
utilizing the system, resulting in a waste of capacity and money.
Their MySQL Solution
Big Fish Games started using MySQL as a small start-up. MySQL allowed Big Fish Games
to quickly grow their business with lower cost and hardware requirements, and has scaled
with the company as it has grown into an industry leader. Today, Big Fish Games deploys
40 MySQL servers to power its popular gaming website which offers thousands of games,
with new games introduced everyday. To achieve the scalability and reliability required
by this high-trafficked website, Big Fish Games relies on MySQL Replication plus, DRBD
is used to improve high availability. In addition to customer-facing material such as the
dynamic website content, e-commerce store, game coupons and discussion forums, the
Contd...

LOVELY PROFESSIONAL UNIVERSITY 249