Technologies/PostgreSQL/postgresql.last_vacuum_age
PostgreSQLPostgreSQLMetric

postgresql.last_vacuum_age

Last vacuum age
Dimensions:None
Available on:DatadogDatadog (2)
Interface Metrics (2)
DatadogDatadog
Last time at which the toast table of this table was vacuumed by the autovacuum daemon. This metric is tagged with db, schema, table.
Dimensions:None
DatadogDatadog
Last time at which the toast table of this table was manually vacuumed (not counting VACUUM FULL). This metric is tagged with db, schema, table.
Dimensions:None
Sources
postgresql.toast.last_autovacuum_agegithub.com
postgresql.toast.last_vacuum_agegithub.com

Technical Annotations (13)

Configuration Parameters (7)
autovacuum_vacuum_threshold
Minimum number of updated/deleted tuples before autovacuum triggers
autovacuum_vacuum_scale_factor
Fraction of table size used to calculate autovacuum trigger threshold
autovacuum_max_workers
Maximum number of concurrent autovacuum processes
autovacuum_naptime
Time between autovacuum runs on each database
autovacuum_freeze_max_agerecommended: 200000000 to 2000000000
maximum transactions before forced anti-wraparound vacuum
vacuum_freeze_min_agerecommended: 50000000
minimum age before freezing rows
vacuum_freeze_table_agerecommended: 0.95 * autovacuum_freeze_max_age
age threshold for aggressive vacuum scanning all pages
CLI Commands (3)
VACUUMremediation
gcloud sql instances patch INSTANCE_NAME --maintenance-window-day=SUN --maintenance-window-hour=2Schedule maintenance during low-transaction period to minimize XID advancement while autovacuum paused
VACUUM (FREEZE, VERBOSE) tablename;Manually freeze transaction IDs after maintenance if wraparound age became critical
Technical References (3)
autovacuumcomponenttransaction ID wraparoundconceptdead tuplesconcept
Related Insights (4)
Inefficient autovacuum configuration causes table bloat and transaction ID wraparound riskcritical
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Blocked autovacuum allows unbounded bloat accumulationcritical
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Autovacuum disabled on static tables delays anti-wraparound vacuumwarning
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Cloud SQL autovacuum disabled during maintenance allows transaction ID wraparoundcritical

Cloud SQL maintenance windows can disable or suspend autovacuum for extended periods (1-4 hours) to perform updates. On high-transaction databases, this suspension allows transaction ID age to advance toward the 2-billion wraparound limit. PostgreSQL's autovacuum_freeze_max_age cannot prevent wraparound if Cloud SQL has paused autovacuum externally.

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