Technologies/PostgreSQL/postgresql.blk_read_time
PostgreSQLPostgreSQLMetric

postgresql.blk_read_time

Block read time
Dimensions:None
Available on:DatadogDatadog (2)Native (2)PrometheusPrometheus (1)
Interface Metrics (5)
DatadogDatadog
The time spent in read operations (if track_io_timing is enabled, otherwise zero). This metric is tagged with backend_type, context, object. Only available with PostgreSQL 16 and newer. (DBM only)
Dimensions:None
DatadogDatadog
Time spent reading data file blocks by backends in this database if track_io_timing is enabled. This metric is tagged with db.
Dimensions:None
Native
read_time statistic from pg_stat_io
Dimensions:None
Native
Time spent reading data file blocks (ms)
Dimensions:None
PrometheusPrometheus
Time spent reading data file blocks by backends in this database, in milliseconds
Dimensions:None
Sources
postgresql.io.read_timegithub.com
postgresql.blk_read_timegithub.com
read_timegithub.com
blk_read_timegithub.com
stat_database_blk_read_timegithub.com

Technical Annotations (21)

Configuration Parameters (4)
track_io_timingrecommended: on
enables collection of I/O timing statistics in pg_stat_statements
cpu_tuple_costrecommended: 0.01
Estimated cost to process one tuple; affects optimizer decisions on scan methods
enable_seqscanrecommended: false
Session-level override to force index usage when sequential scans perform poorly
track_wal_io_timingrecommended: off
default is off due to potential overhead; enable only after testing
CLI Commands (6)
EXPLAIN (ANALYZE, BUFFERS) SELECT ...diagnostic
CREATE INDEX idx_orders_status_created ON orders (status, created_at DESC);remediation
CREATE INDEX ON table_name(filter_column, order_column);remediation
EXPLAIN (ANALYZE, BUFFERS) SELECT ... WHERE a = ? ORDER BY b;diagnostic
set enable_seqscan = false;remediation
pg_test_timingdiagnostic
Technical References (11)
Seq ScanconceptEXPLAIN ANALYZEcomponentBuffers: shared readconceptpg_stat_statementscomponentIndex Scan Backwardconceptbuffersconceptshared bufferscomponentwork memorycomponentshared_bufferscomponentpg_prewarmcomponentpg_test_timingcomponent
Related Insights (6)
Sequential scan on large table causes excessive disk reads and slow query executioncritical
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IO timing statistics unavailable without track_io_timing enabledinfo
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Multi-column index eliminates sort and enables 100x performance improvementwarning
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Sequential scans consume CPU resources during row extraction phaseinfo
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Cold buffer cache causes dramatic sequential scan performance degradationwarning
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I/O timing overhead causes significant performance degradation on some platformswarning
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