Some more comments regarding mmap usage
Change-Id: Ie0c529b801b425b7d94a92ac641b85e4522e2e70
diff --git a/lib/Krawfish/Index/Postings/Lift.pm b/lib/Krawfish/Index/Postings/Lift.pm
index aef951d..123d737 100644
--- a/lib/Krawfish/Index/Postings/Lift.pm
+++ b/lib/Krawfish/Index/Postings/Lift.pm
@@ -8,20 +8,24 @@
# Lift the postingslist file using
#
-# - mmap
+# - mmap and some madvises
#
# or
#
-# - (possibly better suited for our use case)
-# Load the postings lists completely and store them
+# - Load the postings lists completely and store them
# in the coordinator for multiple requests. Use a
-# mtf list structure to make the list remember the latest
+# lru (mtf) structure to make the list remember the latest
# structures. Once a given ratio is exceeded, or the size
# of newly to fetch structures exceed the ratio, forget the latest
# remembered structures.
# Always add newly requested structures to the top of the list.
# The reference to the cached postings list is added
# to the coordination list.
+#
+# See
+# https://sqlite.org/mmap.html for a comparison
+# http://useless-factor.blogspot.de/2011/05/why-not-mmap.html
+# https://dzone.com/articles/use-lucene%E2%80%99s-mmapdirectory
use constant {
DEBUG => 0,