For scientific puroposes, we are addressing a database of over 18.000 enterprises in Austria, which are uploaded into Limesurvey.
Handling of such large lists becomes awkward in LS:
1) There seems to be no way to filter email addresses with logical-operators (e.g. office@maler-den.at OR grg.sek@gix.com) nor a grep()-function.
2) If I want to select all participants via the check box in the column names area, only those rows visible on the page are selected.
3) If I increase the numer of rows (say to 10.000) the browser starts to lag significantly. At times I am not sure wheter the system stops to respond at all. - Also: the column names header does not move while scrolling. To know what information each column contains, one has to scroll all the way up while losing the row of interest.

Proposed fixes:
a) if I want to mass edit my participants I do not need to see each entry. An enumeration of selected cases would be enough thus elminiating a visual representation and therefore foregoing a lagging browser if large lists need to be visible
b) introduction of an elaborate search option where fields can be filtered in complex manner (logical operators and regex-functionality)
c) "Select-all" after filtering should really select all cases, even those not visible on the same page