Take the 2-minute tour ×  What are some of the most expensive
operations in PHP? I know things like overusing the @ operator
can be expensive. What else would you consider?  share|improve
this question why are you trying to catch these tiny perfomance
problems? if your program is slow, it's not because of @ – 
Valentin Golev Dec 24 '09 at 19:26 The "paypal $10 to Paul
Tomblin" one is pretty expensive. But totally worth it. –  Paul
Tomblin Dec 24 '09 at 19:39 @valya I'm trying to get a sense of
the different things that should be avoided where performance is
concerned. I only use the @ operator as an example. –  Darrell
Brogdon Dec 24 '09 at 19:45 add comment  9 Answers  up vote 12
down vote accepted   • serialize() is slow, as is eval(),
create_function(), and spawning additional processes via
system() and related functions.   • beware of anything APC can't
cache -- conditional includes, eval()ed code, etc.   • Opening
database connections. Always cache your connections and re-use
them.   • Object cloning   •