I'll attach a test file.
Take a lookup in 10.000 columns
Unsorted takes ~40 secs on my laptop. Sorted is done in < 1 sec.
(for reference, in 184.108.40.206, unsorted takes more then 4 minutes.)
One might decide that it is good to sort the lookup range.
However… if a value that is seached for, is not available, then there will still be a result returned (see Help on VLOOKUP, 4th argument, (un)sorted)
To prevent this, one could first check if a matching value is available, by use of VLOOKP unsorted ..
So no joy in that approach.
Created attachment 139639 [details]
test file for VLOOKUP performance unsorted
found in Version: 220.127.116.11.alpha0+
Build ID: c7f74bbab4c666a8b3b865dbd58b3666f1f63052
CPU threads: 4; OS: Linux 4.13; UI render: default; VCL: gtk2;
TinderBox: Linux-rpm_deb-x86_64@70-TDF, Branch:master, Time: 2018-02-03_00:22:13
Locale: nl-NL (nl_NL.UTF-8); Calc: group
Created attachment 139640 [details]
callgrind dump attached - stopped the process at roughly 1/5 of the full lookup
Apologies, I should have mentioned in the description that the time is needed to full the full 10,000 rows in column E with the formula.
Michael Meeks committed a patch related to this issue.
It has been pushed to "master":
tdf#115490 - avoid transliteration by using SharedString.
It will be available in 6.1.0.
The patch should be included in the daily builds available at
http://dev-builds.libreoffice.org/daily/ in the next 24-48 hours. More
information about daily builds can be found at:
Affected users are encouraged to test the fix and report feedback.
With a series of patches this comes down from 40seconds to 4.5seconds or thereabouts on Dennis' machine - lets mark this fixed for now =)
works even faster now thanks to Luboš recent commit:
(though difference between ~4 and ~3 seconds for the test file in this issue, is not that noticeable)
Please see the bug below, it seems to me that the problem started after your revision, in 6.0 this problem was not.
(In reply to astrel from comment #8)
> Please see the bug below, it seems to me that the problem started after your
> revision, in 6.0 this problem was not.
Bug 124513 has been traced back to a different commit, if you suspect it's because of a different change, please open a new bug report (but only in that case, use bug 124513 otherwise). Let's keep this closed unless the original issue reported here persists.