[ I recently moved a large time series table from 9.5.4 to 9.6.1 using dump and restore. Although it put the BRIN index on the time column back on, it was borked. Reindexing didn't help. I had to switch it to a regular btree index. I think the data wasn't inserted back into the database in time order. Therefore, because it was all over the place, the efficiency gains from the BRIN index were lost. It was probably because I restored it with "-j 8". -- It is possible something you didn't expect when moving introduce new inefficiencies. I also found running pg_repack after the restore helped performance (and storage size) on my new system too. ]
Do you have all of the kernel settings configured per best practices? Sometimes it is easy to forget them when you get totally focused on just moving the data.
(Things such as your hugepages settings)
With 9.6 you can enable parallel queries. Of course you wouldn't be comparing apples-to-apples then, but take advantage of that feature if you can.
On Wed, Nov 2, 2016 at 9:26 AM, Benjamin Toueg <btoueg@gmail.com> wrote: