A big one in web applications is to prefer streaming over storing everything in RAM.
For example:
str = readEntireFileIntoString()
vs
outputStream.write(readAnotherLine())
Huge huge differences in RAM usage (O(N) vs O(1) ). Streaming is by far preferable.
In XML for example, SAX parsers are far preferable over DOM parsers because the later store everything in RAM. If your file is huge you'll hog a lot of RAM.
Another source of horror is careless use of relations in Hibernate. If you're careless you can end up storing the entire database for each object and hogging the RAM like mad.
Q14: memory usage
A big one in web applications is to prefer streaming over storing everything in RAM.
For example:
str = readEntireFileIntoString()
vs
outputStream.write(readAnotherLine())
Huge huge differences in RAM usage (O(N) vs O(1) ). Streaming is by far preferable.
In XML for example, SAX parsers are far preferable over DOM parsers because the later store everything in RAM. If your file is huge you'll hog a lot of RAM.
Another source of horror is careless use of relations in Hibernate. If you're careless you can end up storing the entire database for each object and hogging the RAM like mad.
I mention these.. because sadly, I've seen them in the wild.