time tr -d '\n' < 250234.txt | egrep 'the...pattern'
real	0m7.178s
user	0m6.592s
sys	0m0.036s

time tr -d '\n' < 250234.txt | LANG=C egrep 'the...pattern'
real	0m0.027s
user	0m0.012s
sys	0m0.008s