One potential hint is the Postgres queries are being executed as sequential scans, as you can see from the explain output. The first query only returns 200k rows (out of 7M), so even without any config tweaks it should be using an index if one is present. So, my guess is those queries are being made against unindexed columns. Also, I'm guessing this is vanilla Postgres, so it's possible OP hasn't tweaked its config for the machine they're using, and the default config pg ships with is designed for fairly resource-constrained machines by today's standards. If the data is indexed, it's possible the rows are all over the place, and clustering could help.