backport of performance enhancements (reduced use of malloc/free) in pqueue.
backport of performance enhancements (reduced use of malloc/free) in pqueue.

zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb