Vacuum and autovacuum I started the second day of PGConf.EU with a session about vacuum and autovacuum, presented by Teresa Lopes.After a short introduction to how MVCC works, she presented the different elements related to autovacuum:What are the different phases of autovacuum? What can trigger autovacuum? Which parameters can influence autovacuum? All these points were explained in a simple and…
Welcome to Valencia! This year, the European PostgreSQL conference, PGConf.EU, takes place at the Palacio de Congresos in Valencia, Spain. I am lucky to be able to attend it with some colleagues from dbi services. Let’s see what’s going on there… I started the first day with a quick tour of the both of the different conference sponsors. I then…
By Franck Pachot . 11gR2 started to have the optimizer react at execution time when a misestimate is encountered. Then the next executions are re-optimized with more accurate estimation, derived from the execution statistics. This was called cardinality feedback. Unfortunately, in rare cases we had a fast execution plan with bad estimations, and better estimations lead to worse execution plan.…
