Hi, On 2019-05-07 18:04:04 +0530, Siddharth Karandikar wrote: > But before reaching there I had done following config changes > - maintenance_work_mem 1GB > - autovacuum off unlikely to matter for a bulk load. > - synchronous_commit off unlikely to matter for a bulk load. > - shared_buffers=4GB > > And finally I explicitly set wal_buffers = 128MB becasue with -1 it > was calculating it to be just 16MB. > > With above configurations, pg9.5 dump of large tables could be > restored on pg10 in just `94m31.869s` - this is huge improvement > compared to 831m25.539s that I was getting before. > Yay!! > > Still not sure why it just worked on to restore on pg9.5 without any > of these config changes. Ah, I bet the wal_level is different in the two clusters. The default in 9.5 wasn't usable for replication and hot backups. But the newer one also has increased overhead in precisely one case - when loading data into a new table. Try setting wal_level = minimal in 10. > And also not sure if this is the best performance that one can get. > Will making wal_buffers 512MB improve it? Extremely unlikely. Regards, Andres
