I need to import data from various database sources. At the moment I plan on importing files via a CSV file or XLS. All the data if in XLS would be on one sheet (notebook). Are there any advantages of using one format over the other? Thanks. David
Both have advantages and disadvantages.
Importing XLS is done using a Java-based application. In my experience, it is terribly slow and eats up enormous amounts of memory to the extent that it blows up your Java heap space, requiring a manual adjustment of this heap space (quite often to no avail). It happens to me all the time that a data structure that I know should fit in memory cannot be imported along the XLS route just because of these memory issues. It does, however, have conveniences such as the ability to read and automatically convert dates and times, select indivudal cells for import, and you can read both formulas and their results.
Importing CSV files with
Import can be much faster and takes less time and memory, although I often resort to reading line by line or as a block using
ReadList and do my own conversions when needed.