On Wed, May 23, 2018 at 6:03 AM, Laurenz Albe <laurenz.a...@cybertec.at> wrote: > I think the cache should be limited in size, perhaps by work_mem. > Also, there probably should be a GUC for this, defaulting to "off".
Eh, why? Generally we want performance optimizations turned on by default; otherwise only highly-knowledgeable users end up getting any benefit. An exception is when there's some significant downside to the optimization, but I don't think I understand what the downside of this could be. Maybe it's bad if we populate the cache and never use it? But until the patch is written we don't know whether there's really a case that regresses like that, and if there is, it would be better to fix it so it doesn't rather than make the feature off-by-default. -- Robert Haas EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company
