PHP references and performance
62129
In PHP (>= 5.0), is passing by reference faster?
63905
Tracking Memory Usage in PHP
81810
What's the best way to store class variables in PHP?
68829
Is it necessary to declare PHP array before adding values with []?
14596
Are PHP Variables passed by value or by reference?
12387
What is "Best Practice" For Comparing Two Instances of a Reference Type?
11951
Should I use properties or direct reference when accessing instance variables internally?
120506
Performance/efficiency of 2 SELECT statements vs UNION vs anything else in MySQL-PHP
19612
Fastest way to retrieve a  in PHP
48603
When to use ref and when it is not necessary in C#
37674
\ref shows names of referenced objects
46785
Circular References Cause Memory Leak?
133214
Can moving tables to another MySQL database help performance?
104346
Does PHP have short-circuit evaluation?
7323
What is the point of interfaces in PHP?
137018
Weirdness in Equated Java Arrays: References vs. Pointers
50195
Determining Referer in PHP