PS:
What I forgot to mention was that inserting records into the table
is also about 2-3 times slower than before (most likely due to the
slow index update operations).
I dropped the whole database and restored the dumpfile, but the
result it the same. When the index is recreated after COPYing the
data, it takes more than 20 minutes for _each_ of both tsearch2
indexes. So the total time to restore this table is more than 45
minutes!
- Stephan