Originally posted by tal_olier
Are you sure the same will happen with 30 current users and 50GB db ?
Not sure what you mean. What does the number of users or the size of the database have to do with the performance of the LIKE function? My test just shows that there is some apparent overhead in using the ESCAPE clause. It probably wouldn't be 10% in all queries - my test query was a particularly nasty one because the search string began with '%'. I just tried it with 'EMP%' instead of '%EMP%' and the overhead became unnoticeable. Presumably this has something to do with how many records it has to apply the ESCAPE to.
I suspect you are in unknown territory here, and the only way to be sure that it will not be detrimental to your application is to benchmark it with your tables and queries.