News for hackers. Stuff that matters.

A comment on A Major Postgres Upgrade with Zero Downtime. Parent comment

Re:A Major Postgres Upgrade with Zero Downtime by zonkd1234 on Thursday January 30, 2025 @06:28PM (#42883297)
Was it unusable because cpu/io was maxed out during ANALYZE?
[ Parent | on HN ]
Re:A Major Postgres Upgrade with Zero Downtime by pilif on Thursday January 30, 2025 @11:41PM (#42884750)
Analyze itself isn’t the problem.

After pg_upgrade, no stats will be available for the optimizer which means that any query will more or less sequence-scan all affected tables.

[ Parent | on HN ]
Re:A Major Postgres Upgrade with Zero Downtime by timacles on Friday January 31, 2025 @09:14AM (#42887885)
No, its the lack of stats on the tables, any query hitting a medium to large table would be extremely slow.
[ Parent | on HN ]