- Create bitvector when freqency > 1/64, up from 1/32

- Destruct bitvector when frequency falls below 1/128 instead of 1/64.
A posting is currently 8 bytes(docid+weight) + btree overhead, so that will give a smoother memory cost.
In addition filter queries should be faster.

1 files changed, 2 insertions, 2 deletions

diff --git a/searchlib/src/vespa/searchlib/attribute/postingstore.cpp b/searchlib/src/vespa/searchlib/attribute/postingstore.cpp
index 8bee8b3f7f7..ca56274bd36 100644
--- a/searchlib/src/vespa/searchlib/attribute/postingstore.cpp
+++ b/searchlib/src/vespa/searchlib/attribute/postingstore.cpp
@@ -44,8 +44,8 @@ PostingStoreBase2::resizeBitVectors(uint32_t newSize, uint32_t newCapacity)
         newSize = newCapacity;
     if (newSize == _bvSize && newCapacity == _bvCapacity)
         return false;
-    _minBvDocFreq = std::max(newSize >> 6, 64u);
-    _maxBvDocFreq = std::max(newSize >> 5, 128u);
+    _minBvDocFreq = std::max(newSize >> 7, 64u);
+    _maxBvDocFreq = std::max(newSize >> 6, 128u);
     if (_bvs.empty()) {
         _bvSize = newSize;
         _bvCapacity = newCapacity;