Progress Reporting In PostgreSQL
Bolaji Wahab
Posted on April 10, 2023
Can we monitor the progress of certain operations in PostgreSQL? Yes, we can monitor the progress of these operations in PostgreSQL:
- create index
- create index concurrently
- reindex
- reindex concurrently
- vacuum
- vacuum analyze
- vacuum full
- analyze
- copy
- cluster
- basebackup
Let us jump right into it. The query snippets below can be used to monitor the progress of the listed-above operations.
Monitoring the progress of create index, create index concurrently, reindex, reindex concurrently
SELECT p.datname AS database_name,
p.pid,
clock_timestamp() - a.xact_start AS duration_so_far,
a.application_name,
a.client_addr,
a.usename,
coalesce(a.wait_event_type ||'.'|| a.wait_event, 'false') AS waiting,
p.command,
trim(trailing ';' from a.query) AS query,
a.state,
p.index_relid::regclass AS index_name,
p.relid::regclass AS table_name,
pg_size_pretty(pg_relation_size(p.relid)) AS table_size,
p.phase,
CASE p.phase
WHEN 'initializing' THEN '1 of 12'
WHEN 'waiting for writers before build' THEN '2 of 12'
WHEN 'building index: scanning table' THEN '3 of 12'
WHEN 'building index: sorting live tuples' THEN '4 of 12'
WHEN 'building index: loading tuples in tree' THEN '5 of 12'
WHEN 'waiting for writers before validation' THEN '6 of 12'
WHEN 'index validation: scanning index' THEN '7 of 12'
WHEN 'index validation: sorting tuples' THEN '8 of 12'
WHEN 'index validation: scanning table' THEN '9 of 12'
WHEN 'waiting for old snapshots' THEN '10 of 12'
WHEN 'waiting for readers before marking dead' THEN '11 of 12'
WHEN 'waiting for readers before dropping' THEN '12 of 12'
END AS phase_progress,
format(
'%s (%s of %s)',
coalesce(round(100.0 * p.blocks_done / nullif(p.blocks_total, 0), 2)::text || '%', 'not applicable'),
p.blocks_done::text,
p.blocks_total::text
) AS scan_progress,
format(
'%s (%s of %s)',
coalesce(round(100.0 * p.tuples_done / nullif(p.tuples_total, 0), 2)::text || '%', 'not applicable'),
p.tuples_done::text,
p.tuples_total::text
) AS tuples_loading_progress,
format(
'%s (%s of %s)',
coalesce((100 * p.lockers_done / nullif(p.lockers_total, 0))::text || '%', 'not applicable'),
p.lockers_done::text,
p.lockers_total::text
) AS lockers_progress,
format(
'%s (%s of %s)',
coalesce((100 * p.partitions_done / nullif(p.partitions_total, 0))::text || '%', 'not applicable'),
p.partitions_done::text,
p.partitions_total::text
) AS partitions_progress,
p.current_locker_pid,
trim(trailing ';' from l.query) AS current_locker_query
FROM pg_stat_progress_create_index AS p
JOIN pg_stat_activity AS a ON a.pid = p.pid
LEFT JOIN pg_stat_activity AS l ON l.pid = p.current_locker_pid
ORDER BY clock_timestamp() - a.xact_start DESC;
Monitoring the progress of vacuum, vacuum analyze
SELECT p.datname AS database_name,
p.pid,
clock_timestamp() - a.xact_start AS duration_so_far,
a.application_name,
a.client_addr,
a.usename,
coalesce(a.wait_event_type ||'.'|| a.wait_event, 'false') AS waiting,
trim(trailing ';' from a.query) AS query,
a.state,
p.relid::regclass AS table_name,
pg_size_pretty(pg_relation_size(p.relid)) AS table_size,
pg_size_pretty(pg_total_relation_size(p.relid)) AS total_table_size,
CASE
WHEN ltrim(a.query) ~* '^autovacuum.to prevent wraparound' THEN 'wraparound'
WHEN ltrim(a.query) ~ '^vacuum' THEN 'user'
ELSE 'regular'
END AS mode,
p.phase,
CASE p.phase
WHEN 'initializing' THEN '1 of 7'
WHEN 'scanning heap' THEN '2 of 7'
WHEN 'vacuuming indexes' THEN '3 of 7'
WHEN 'vacuuming heap' THEN '4 of 7'
WHEN 'cleaning up indexes' THEN '5 of 7'
WHEN 'truncating heap' THEN '6 of 7'
WHEN 'performing final cleanup' THEN '7 of 7'
END AS vacuum_phase_progress,
format(
'%s (%s of %s)',
coalesce(round(100.0 * p.heap_blks_scanned / nullif(p.heap_blks_total, 0), 2)::text || '%', 'not applicable'),
p.heap_blks_scanned::text,
p.heap_blks_total::text
) AS vacuum_scan_progress,
format(
'%s (%s of %s)',
coalesce(round(100.0 * p.heap_blks_vacuumed / nullif(p.heap_blks_total, 0), 2)::text || '%', 'not applicable'),
p.heap_blks_vacuumed::text,
p.heap_blks_total::text
) AS vacuum_progress,
p.index_vacuum_count,
p.max_dead_tuples,
p.num_dead_tuples
FROM pg_stat_progress_vacuum AS p
JOIN pg_stat_activity AS a ON a.pid = p.pid
ORDER BY clock_timestamp() - a.xact_start DESC;
Monitoring the progress of vacuum full, cluster
SELECT p.datname AS database_name,
p.pid,
clock_timestamp() - a.xact_start AS duration_so_far,
a.application_name,
a.client_addr,
a.usename,
coalesce(a.wait_event_type ||'.'|| a.wait_event, 'false') AS waiting,
p.command,
trim(trailing ';' from a.query) AS query,
a.state,
p.relid::regclass AS table_name,
p.phase,
CASE p.phase
WHEN 'initializing' THEN '1 of 8'
WHEN 'seq scanning heap' THEN '2 of 8'
WHEN 'index scanning heap' THEN '3 of 8'
WHEN 'sorting tuples' THEN '4 of 8'
WHEN 'writing new heap' THEN '5 of 8'
WHEN 'swapping relation files' THEN '6 of 8'
WHEN 'rebuilding index' THEN '7 of 8'
WHEN 'performing final cleanup' THEN '7 of 8'
END AS vacuum_phase_progress,
cluster_index_relid::regclass AS cluster_index,
format(
'%s (%s of %s)',
coalesce(round(100.0 * p.heap_blks_scanned / nullif(p.heap_blks_total, 0), 2)::text || '%', 'not applicable'),
p.heap_blks_scanned::text,
p.heap_blks_total::text
) AS heap_scan_progress,
format(
'%s (%s of %s)',
coalesce(round(100.0 * p.heap_tuples_written / nullif(p.heap_tuples_scanned, 0), 2)::text || '%', 'not applicable'),
p.heap_tuples_written::text,
p.heap_tuples_scanned::text
) AS heap_tuples_written_progress,
p.index_rebuild_count
FROM pg_stat_progress_cluster AS p
JOIN pg_stat_activity AS a ON a.pid = p.pid
ORDER BY clock_timestamp() - a.xact_start DESC;
Monitoring the progress of analyze
SELECT p.datname AS database_name,
p.pid,
clock_timestamp() - a.xact_start AS duration_so_far,
a.application_name,
a.client_addr,
a.usename,
coalesce(a.wait_event_type ||'.'|| a.wait_event, 'false') AS waiting,
trim(trailing ';' from a.query) AS query,
a.state,
p.relid::regclass AS table_name,
pg_size_pretty(pg_relation_size(p.relid)) AS table_size,
pg_size_pretty(pg_total_relation_size(p.relid)) AS total_table_size,
CASE
WHEN ltrim(a.query) ~* '^analyze' THEN 'user'
ELSE 'regular'
END AS mode,
p.phase,
CASE p.phase
WHEN 'initializing' THEN '1 of 6'
WHEN 'acquiring sample rows' THEN '2 of 6'
WHEN 'acquiring inherited sample rows' THEN '3 of 6'
WHEN 'computing statistics' THEN '4 of 6'
WHEN 'computing extended statistics' THEN '5 of 6'
WHEN 'finalizing analyze' THEN '6 of 6'
END AS phase_progress,
format(
'%s (%s of %s)',
coalesce(round(100.0 * p.sample_blks_scanned / nullif(p.sample_blks_total, 0), 2)::text || '%', 'not applicable'),
p.sample_blks_scanned::text,
p.sample_blks_total::text
) AS scan_progress,
format(
'%s (%s of %s)',
coalesce((100 * p.ext_stats_computed / nullif(p.ext_stats_total, 0))::text || '%', 'not applicable'),
p.ext_stats_computed::text,
p.ext_stats_total::text
) AS extended_statistics_progress,
format(
'%s (%s of %s)',
coalesce((100 * p.ext_stats_computed / nullif(p.child_tables_total, 0))::text || '%', 'not applicable'),
p.child_tables_done::text,
p.child_tables_total::text
) AS child_tables_progress,
current_child_table_relid::regclass AS current_child_table
FROM pg_stat_progress_analyze AS p
JOIN pg_stat_activity AS a ON a.pid = p.pid
ORDER BY clock_timestamp() - a.xact_start DESC;
Monitoring the progress of copy
SELECT p.datname AS database_name,
p.pid,
clock_timestamp() - a.xact_start AS duration_so_far,
a.application_name,
a.client_addr,
a.usename,
coalesce(a.wait_event_type ||'.'|| a.wait_event, 'false') AS waiting,
p.command,
p.type,
trim(trailing ';' from a.query) AS query,
a.state,
p.relid::regclass AS table_name,
coalesce(pg_size_pretty(pg_relation_size(p.relid)), '-') AS table_size,
coalesce(pg_size_pretty(pg_total_relation_size(p.relid)), '-') AS total_table_size,
format(
'%s (%s of %s)',
coalesce(round(100.0 * p.bytes_processed / nullif(p.bytes_total, 0), 2)::text || '%', 'not applicable'),
p.bytes_processed::text,
p.bytes_total::text
) AS bytes_progress,
p.tuples_processed,
p.tuples_excluded
FROM pg_stat_progress_copy AS p
JOIN pg_stat_activity AS a ON a.pid = p.pid
ORDER BY clock_timestamp() - a.xact_start DESC;
Monitoring the progress of basebackup
SELECT a.datname AS database_name,
p.pid,
clock_timestamp() - a.query_start AS duration_so_far,
a.application_name,
a.client_addr,
a.usename,
coalesce(a.wait_event_type ||'.'|| a.wait_event, 'false') AS waiting,
trim(trailing ';' from a.query) AS query,
a.state,
p.phase,
CASE p.phase
WHEN 'initializing' THEN '1 of 6'
WHEN 'waiting for checkpoint to finish' THEN '2 of 6'
WHEN 'estimating backup size' THEN '3 of 6'
WHEN 'streaming database files' THEN '4 of 6'
WHEN 'waiting for wal archiving to finish' THEN '5 of 6'
WHEN 'transferring wal files' THEN '6 of 6'
END AS phase_progress,
format(
'%s (%s of %s)',
coalesce(round(100.0 * p.backup_streamed / nullif(p.backup_total, 0), 2)::text || '%', 'not applicable'),
p.backup_streamed::text,
coalesce(p.backup_total::text, '0')
) AS backup_progress,
format(
'%s (%s of %s)',
coalesce((100 * p.tablespaces_streamed / nullif(p.tablespaces_total, 0))::text || '%', 'not applicable'),
p.tablespaces_streamed::text,
p.tablespaces_total::text
) AS tablespace_progress
FROM pg_stat_progress_basebackup AS p
JOIN pg_stat_activity AS a ON a.pid = p.pid
ORDER BY clock_timestamp() - a.query_start DESC;
Little explanation:
The above queries have lot of things in common.
- There is a phase column which tells what phase the process is currently on.
- A
phase_progresswhich gives the ratio of the current phase number and the total expected number of phases, which is gotten from the description of the respective views. - Then we have progress for the phases provided they are available otherwise
not applicable. - For system/user commands such as analyze and vacuum, we have this expression
trim(leading from a.query)which removes leading spaces before we compare to deduce whether it isautovacuum/autoanalyzeormanual vacuum/manual analyze. - The combination of
coalesceandnullifproducesnot applicablewhen one of the variables isNULLor0. - Expression
coalesce(a.wait_event_type ||'.'|| a.wait_event, 'false')gives details whether the process is waiting or not. - Finally,
trim(trailing ';' from a.query)removes;from the query text to give a nice format.
I hope you find these queries useful for your progress reporting.
P.S: All queries were tested on PostgreSQL 14.
Posted on April 10, 2023
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