performance: conditional formats problematic
gnumeric is fantastically fast, I experienced two exceptions:
- comments,
- conditional formats,
applying too many of either produces slowsdowns until final freeze,
Test: copy cells B4:C5 on the sheet 'comments' or 'conditional_formats' of performance_problems.gnumeric to B4:C65536
-> stall. ( inserting 5.000 copies needs time but finishes )
add. details - Click to expand
IMHO it's not a matter of the random cells, the same copy on sheet 'neutral' shows no problem.
Assumption: the data structure for comments and conditional formats or the access to them is not optimized, quadratic explosion?
Importance? The test is an arbitrary stress test, but similar things can happen in normal use. Knowing the reasons I can avoid such structures in my work, but it unexpectedly hits innocent careless users now and then, and can cause data loss. AFAIK gnumeric has no automatic backup before critical actions, and no option to terminate hanging actions 'softly' - without total termination.
If the issue can't be eliminated I would recommend to issue a warning before inserting many cells with comments or conditional formats.