PG 10.5 I loaded 133 million rows to a wide table (more than 100 cols) via COPY. The table has no index at this time. Since I am the only user I don't see any other activity. Now when I run select count(*) on the table where I just loaded data, it runs for ever, more than 10min and still running. Intrigued, I checked locks and saw nothing. Then I noticed something strange. When select count(*) runs, PG is writing to wal_logs, and that too a large amount. Why? I suspect vaccum is getting triggered, but this is a brand new table with no updates. So it should not.
Is there a SQL to peek into what PG is doing to write so much to WAL logs ?
