[XML-SIG] will SAX be suitable for this task?

[oliver]

hi, 

Being a pretty much beginer of both python and XML, I am facing the choice
of which API I should use for the following task and hope to get some
help.

I have a potentially very large data file, composed by a fixed number type
of format, each type can appear multiple times. The task involves
searching a certain record (with certain criteria) and then searching
backward or forward from that point (depending on the situation). My
impression with SAX is that it is more suitable for one-time pass
processing, there is no "stoping-point" where you can go backward. Am I
right? 

I don't know much about DOM, but reading file to memeory and manipulating
a tree sounds like a overkill and may not be practical when the file size
is very large.

Since all the comments are speculation not first hand experience, please
correct me if I am wrong, and any suggestions are also appreciated.

Thanks

oliver