Quote:
Originally Posted by BookJunkieLI
So Composite Columns shouldn't cause a noticeable slowdown in Calibre? I ask because while looking for a way to clear out old Send To Device templates I found this thread - Send to device - Template help - and was giving serious thought to turning my export template into a composite column and then just pointing Send To Device to that. It currently calls 13 different columns. |
I wouldn't go as far as to make a blanket statement "composite columns won't affect performance". They might. Why?
- If you sort on them then the must be evaluated for every book before the sort finishes.
- Same is true if you search on them. The values for every book must be computed before results can be displayed.
- Some templates require looking at the drive (mostly the formats_ functions). The result is cached but the evaluation can be slow.
Composite columns that are displayed in the spreadsheet will be evaluated as needed (as displayed). If the template is some huge program than it could be slow, but almost no one does this, and if you do then you should consider writing a custom template function.