Hi!
I've created section about testing in project wiki page:
http://wiki.postgresql.org/wiki/Fast_GiST_index_build_GSoC_2011#Testing_results Do you have any notes about table structure?
As you can see I found that CPU usage might be much higher with gist_trgm_ops. I believe it's due to relatively expensive penalty method in that opclass. But, probably index build can be still faster when index doesn't fit cache even for gist_trgm_ops. Also with that opclass index quality is slightly worse but the difference is not dramatic.
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With best regards,
Alexander Korotkov.
