Without knowing which driver you are using, most certainly not. The way you are doing it duplicates data - you are using bind variables and
you are using fetchall_arrayref
. Furthermore, you first fetch every row in a big table, then you loop over it (in a, IMO, weird way) and slightly rearrange it. You're doing quite a lot of data duplications, even before you do anything with the data.
First you have to answer the question: do I need all 100000 rows before I do any processing? Or do you want to process each row? In which case you're (probably) better off fetching a row at the time, doing the processing, then fetching the next. Note I say probably - if the processing takes a long time, you are holding resources (perhaps even locks) in the database which may influence other processes accessing the data.
AFAIK, bind variables and fetchrow_arrayref are the fastests way to retrieve data - with bind variables probably the fastest (but I haven't benchmarked it myself, and it may vary between drivers). I never use bind variables, as I don't like its action at a distance, but if fetching was the bottleneck of a time critical program, I'd certainly look into it.