Amit Kapila wrote: > You might want to give a try with the hash index if you are planning > to use PG10 and your queries involve equality operations.
So, btree indexes on monotonically increasing sequences don't write tons of full page writes because typically the same page is touched many times by insertions on each checkpoint cycle; so only one or very few full page writes are generated for a limited number of index pages. With UUID you lose locality of access: each insert goes to a different btree page, so you generate tons of full page writes because the number of modified index pages is very large. With hash on monotonically increasing keys, my guess is that you get behavior similar to btrees on UUID: the inserts are all over the place in the index, so tons of full page writes. Am I wrong? With hash on UUID, the same thing should happen. Am I wrong? -- Álvaro Herrera https://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
