transaction import is impossibly slow

[Steve Kelem]

   I downloaded transactions from my credit card company into a fresh
   gnucash account.
   The account display shows lots of transactions (good).
   The transaction matcher has a colorful display of lots of transactions.
   After I click on OK, gnucash works away for hours. It shouldn't take
   that long.
   Why is this so slow?  My search through old gnucash email, matching the
   word "slow", shows that in March of 2009, someone named Matthew was
   going to look into whether hash tables were either (implemented) or
   needed to be tuned in order to fix the slowness of importing
   transactions. Has any progress been made for gnucash performance? It's
   been almost 4 years.
   A linear search for a single item in a list of size m has performance
   proportional to n*m/2 for n items, which, is essentially n^2 for large
   n.
   A hash table search for n items is proportional to only n, not to the
   number of items in the list, m.
   Steve
   GnuCash 2.4.11
   Built 2012-09-20 from r22264M
   Ubuntu 12.10
   x86-64 oct-processor