Hi, I have a table which has ~26M records in it. But pg_class shows ~35M in the "reltuples" column. last_autovacuum is null, and last_autoanalyze was just on yesterday.
I tried running vacuum analyze on it, but the analyze result shows: INFO: "[table name]": scanned 30000 of 950145 pages, containing 805842 live rows and 11109 dead rows; 30000 rows in sample, 42266462 estimated total rows Even worse estimates. I know that it's doing an estimate, but it's too wrong. I have another table for which pg_class estimates 3 times the actual number of rows. I'm using 9.1.3 and vacuum settings are: # grep vacuum postgresql.conf vacuum_cost_delay = 25ms # 0-100 milliseconds #vacuum_cost_page_hit = 1 # 0-10000 credits #vacuum_cost_page_miss = 10 # 0-10000 credits #vacuum_cost_page_dirty = 20 # 0-10000 credits #vacuum_cost_limit = 200 # 1-10000 credits #vacuum_defer_cleanup_age = 0 # number of xacts by which cleanup is delayed #autovacuum = on # Enable autovacuum subprocess? 'on' log_autovacuum_min_duration = 60000 # -1 disables, 0 logs all actions and autovacuum_max_workers = 6 # max number of autovacuum subprocesses autovacuum_naptime = 15s # time between autovacuum runs autovacuum_vacuum_threshold = 1000 # min number of row updates before # vacuum autovacuum_analyze_threshold = 100 # min number of row updates before #autovacuum_vacuum_scale_factor = 0.2 # fraction of table size before vacuum #autovacuum_analyze_scale_factor = 0.1 # fraction of table size before analyze #autovacuum_freeze_max_age = 200000000 # maximum XID age before forced vacuum autovacuum_vacuum_cost_delay = 10ms # default vacuum cost delay for # autovacuum, in milliseconds; # -1 means use vacuum_cost_delay autovacuum_vacuum_cost_limit = 1000 # default vacuum cost limit for # autovacuum, -1 means use # vacuum_cost_limit #vacuum_freeze_min_age = 50000000 #vacuum_freeze_table_age = 150000000 Host machine has 32GB memory. I set effective_cache_size to 16GB, and shared_buffers to 8GB. We have other machines with exactly the same data/configuration but didn't get into such situation. Can you give me some advice? Thanks a lot, Qingbo
