pg_stat_all_tables 是一个 统计视图，显示当前数据库中每个表访问的统计信息。
pg_stat_all_tables 在 PostgreSQL 7.2 中添加。
按 PostgreSQL 版本定义
pg_stat_all_tables (PostgreSQL 19)
View "pg_catalog.pg_stat_all_tables"
Column | Type | Collation | Nullable | Default
------------------------+--------------------------+-----------+----------+---------
relid | oid | | |
schemaname | name | | |
relname | name | | |
seq_scan | bigint | | |
last_seq_scan | timestamp with time zone | | |
seq_tup_read | bigint | | |
idx_scan | bigint | | |
last_idx_scan | timestamp with time zone | | |
idx_tup_fetch | bigint | | |
n_tup_ins | bigint | | |
n_tup_upd | bigint | | |
n_tup_del | bigint | | |
n_tup_hot_upd | bigint | | |
n_tup_newpage_upd | bigint | | |
n_live_tup | bigint | | |
n_dead_tup | bigint | | |
n_mod_since_analyze | bigint | | |
n_ins_since_vacuum | bigint | | |
last_vacuum | timestamp with time zone | | |
last_autovacuum | timestamp with time zone | | |
last_analyze | timestamp with time zone | | |
last_autoanalyze | timestamp with time zone | | |
vacuum_count | bigint | | |
autovacuum_count | bigint | | |
analyze_count | bigint | | |
autoanalyze_count | bigint | | |
total_vacuum_time | double precision | | |
total_autovacuum_time | double precision | | |
total_analyze_time | double precision | | |
total_autoanalyze_time | double precision | | |
pg_stat_all_tables (PostgreSQL 18)
View "pg_catalog.pg_stat_all_tables"
Column | Type | Collation | Nullable | Default
------------------------+--------------------------+-----------+----------+---------
relid | oid | | |
schemaname | name | | |
relname | name | | |
seq_scan | bigint | | |
last_seq_scan | timestamp with time zone | | |
seq_tup_read | bigint | | |
idx_scan | bigint | | |
last_idx_scan | timestamp with time zone | | |
idx_tup_fetch | bigint | | |
n_tup_ins | bigint | | |
n_tup_upd | bigint | | |
n_tup_del | bigint | | |
n_tup_hot_upd | bigint | | |
n_tup_newpage_upd | bigint | | |
n_live_tup | bigint | | |
n_dead_tup | bigint | | |
n_mod_since_analyze | bigint | | |
n_ins_since_vacuum | bigint | | |
last_vacuum | timestamp with time zone | | |
last_autovacuum | timestamp with time zone | | |
last_analyze | timestamp with time zone | | |
last_autoanalyze | timestamp with time zone | | |
vacuum_count | bigint | | |
autovacuum_count | bigint | | |
analyze_count | bigint | | |
autoanalyze_count | bigint | | |
total_vacuum_time | double precision | | |
total_autovacuum_time | double precision | | |
total_analyze_time | double precision | | |
total_autoanalyze_time | double precision | | |
pg_stat_all_tables (PostgreSQL 17)
View "pg_catalog.pg_stat_all_tables"
Column | Type | Collation | Nullable | Default
---------------------+--------------------------+-----------+----------+---------
relid | oid | | |
schemaname | name | | |
relname | name | | |
seq_scan | bigint | | |
last_seq_scan | timestamp with time zone | | |
seq_tup_read | bigint | | |
idx_scan | bigint | | |
last_idx_scan | timestamp with time zone | | |
idx_tup_fetch | bigint | | |
n_tup_ins | bigint | | |
n_tup_upd | bigint | | |
n_tup_del | bigint | | |
n_tup_hot_upd | bigint | | |
n_tup_newpage_upd | bigint | | |
n_live_tup | bigint | | |
n_dead_tup | bigint | | |
n_mod_since_analyze | bigint | | |
n_ins_since_vacuum | bigint | | |
last_vacuum | timestamp with time zone | | |
last_autovacuum | timestamp with time zone | | |
last_analyze | timestamp with time zone | | |
last_autoanalyze | timestamp with time zone | | |
vacuum_count | bigint | | |
autovacuum_count | bigint | | |
analyze_count | bigint | | |
autoanalyze_count | bigint | | |
pg_stat_all_tables (PostgreSQL 16)
View "pg_catalog.pg_stat_all_tables"
Column | Type | Collation | Nullable | Default
---------------------+--------------------------+-----------+----------+---------
relid | oid | | |
schemaname | name | | |
relname | name | | |
seq_scan | bigint | | |
last_seq_scan | timestamp with time zone | | |
seq_tup_read | bigint | | |
idx_scan | bigint | | |
last_idx_scan | timestamp with time zone | | |
idx_tup_fetch | bigint | | |
n_tup_ins | bigint | | |
n_tup_upd | bigint | | |
n_tup_del | bigint | | |
n_tup_hot_upd | bigint | | |
n_tup_newpage_upd | bigint | | |
n_live_tup | bigint | | |
n_dead_tup | bigint | | |
n_mod_since_analyze | bigint | | |
n_ins_since_vacuum | bigint | | |
last_vacuum | timestamp with time zone | | |
last_autovacuum | timestamp with time zone | | |
last_analyze | timestamp with time zone | | |
last_autoanalyze | timestamp with time zone | | |
vacuum_count | bigint | | |
autovacuum_count | bigint | | |
analyze_count | bigint | | |
autoanalyze_count | bigint | | |
pg_stat_all_tables (PostgreSQL 15)
View "pg_catalog.pg_stat_all_tables"
Column | Type | Collation | Nullable | Default
---------------------+--------------------------+-----------+----------+---------
relid | oid | | |
schemaname | name | | |
relname | name | | |
seq_scan | bigint | | |
seq_tup_read | bigint | | |
idx_scan | bigint | | |
idx_tup_fetch | bigint | | |
n_tup_ins | bigint | | |
n_tup_upd | bigint | | |
n_tup_del | bigint | | |
n_tup_hot_upd | bigint | | |
n_live_tup | bigint | | |
n_dead_tup | bigint | | |
n_mod_since_analyze | bigint | | |
n_ins_since_vacuum | bigint | | |
last_vacuum | timestamp with time zone | | |
last_autovacuum | timestamp with time zone | | |
last_analyze | timestamp with time zone | | |
last_autoanalyze | timestamp with time zone | | |
vacuum_count | bigint | | |
autovacuum_count | bigint | | |
analyze_count | bigint | | |
autoanalyze_count | bigint | | |
pg_stat_all_tables (PostgreSQL 14)
View "pg_catalog.pg_stat_all_tables"
Column | Type | Collation | Nullable | Default
---------------------+--------------------------+-----------+----------+---------
relid | oid | | |
schemaname | name | | |
relname | name | | |
seq_scan | bigint | | |
seq_tup_read | bigint | | |
idx_scan | bigint | | |
idx_tup_fetch | bigint | | |
n_tup_ins | bigint | | |
n_tup_upd | bigint | | |
n_tup_del | bigint | | |
n_tup_hot_upd | bigint | | |
n_live_tup | bigint | | |
n_dead_tup | bigint | | |
n_mod_since_analyze | bigint | | |
n_ins_since_vacuum | bigint | | |
last_vacuum | timestamp with time zone | | |
last_autovacuum | timestamp with time zone | | |
last_analyze | timestamp with time zone | | |
last_autoanalyze | timestamp with time zone | | |
vacuum_count | bigint | | |
autovacuum_count | bigint | | |
analyze_count | bigint | | |
autoanalyze_count | bigint | | |
pg_stat_all_tables (PostgreSQL 13)
View "pg_catalog.pg_stat_all_tables"
Column | Type | Collation | Nullable | Default
---------------------+--------------------------+-----------+----------+---------
relid | oid | | |
schemaname | name | | |
relname | name | | |
seq_scan | bigint | | |
seq_tup_read | bigint | | |
idx_scan | bigint | | |
idx_tup_fetch | bigint | | |
n_tup_ins | bigint | | |
n_tup_upd | bigint | | |
n_tup_del | bigint | | |
n_tup_hot_upd | bigint | | |
n_live_tup | bigint | | |
n_dead_tup | bigint | | |
n_mod_since_analyze | bigint | | |
n_ins_since_vacuum | bigint | | |
last_vacuum | timestamp with time zone | | |
last_autovacuum | timestamp with time zone | | |
last_analyze | timestamp with time zone | | |
last_autoanalyze | timestamp with time zone | | |
vacuum_count | bigint | | |
autovacuum_count | bigint | | |
analyze_count | bigint | | |
autoanalyze_count | bigint | | |
pg_stat_all_tables (PostgreSQL 12)
View "pg_catalog.pg_stat_all_tables"
Column | Type | Collation | Nullable | Default
---------------------+--------------------------+-----------+----------+---------
relid | oid | | |
schemaname | name | | |
relname | name | | |
seq_scan | bigint | | |
seq_tup_read | bigint | | |
idx_scan | bigint | | |
idx_tup_fetch | bigint | | |
n_tup_ins | bigint | | |
n_tup_upd | bigint | | |
n_tup_del | bigint | | |
n_tup_hot_upd | bigint | | |
n_live_tup | bigint | | |
n_dead_tup | bigint | | |
n_mod_since_analyze | bigint | | |
last_vacuum | timestamp with time zone | | |
last_autovacuum | timestamp with time zone | | |
last_analyze | timestamp with time zone | | |
last_autoanalyze | timestamp with time zone | | |
vacuum_count | bigint | | |
autovacuum_count | bigint | | |
analyze_count | bigint | | |
autoanalyze_count | bigint | | |
pg_stat_all_tables (PostgreSQL 11)
View "pg_catalog.pg_stat_all_tables"
Column | Type | Collation | Nullable | Default
---------------------+--------------------------+-----------+----------+---------
relid | oid | | |
schemaname | name | | |
relname | name | | |
seq_scan | bigint | | |
seq_tup_read | bigint | | |
idx_scan | bigint | | |
idx_tup_fetch | bigint | | |
n_tup_ins | bigint | | |
n_tup_upd | bigint | | |
n_tup_del | bigint | | |
n_tup_hot_upd | bigint | | |
n_live_tup | bigint | | |
n_dead_tup | bigint | | |
n_mod_since_analyze | bigint | | |
last_vacuum | timestamp with time zone | | |
last_autovacuum | timestamp with time zone | | |
last_analyze | timestamp with time zone | | |
last_autoanalyze | timestamp with time zone | | |
vacuum_count | bigint | | |
autovacuum_count | bigint | | |
analyze_count | bigint | | |
autoanalyze_count | bigint | | |
pg_stat_all_tables (PostgreSQL 10)
View "pg_catalog.pg_stat_all_tables"
Column | Type | Collation | Nullable | Default
---------------------+--------------------------+-----------+----------+---------
relid | oid | | |
schemaname | name | | |
relname | name | | |
seq_scan | bigint | | |
seq_tup_read | bigint | | |
idx_scan | bigint | | |
idx_tup_fetch | bigint | | |
n_tup_ins | bigint | | |
n_tup_upd | bigint | | |
n_tup_del | bigint | | |
n_tup_hot_upd | bigint | | |
n_live_tup | bigint | | |
n_dead_tup | bigint | | |
n_mod_since_analyze | bigint | | |
last_vacuum | timestamp with time zone | | |
last_autovacuum | timestamp with time zone | | |
last_analyze | timestamp with time zone | | |
last_autoanalyze | timestamp with time zone | | |
vacuum_count | bigint | | |
autovacuum_count | bigint | | |
analyze_count | bigint | | |
autoanalyze_count | bigint | | |
pg_stat_all_tables (PostgreSQL 9.6)
View "pg_catalog.pg_stat_all_tables"
Column | Type | Modifiers
---------------------+--------------------------+-----------
relid | oid |
schemaname | name |
relname | name |
seq_scan | bigint |
seq_tup_read | bigint |
idx_scan | bigint |
idx_tup_fetch | bigint |
n_tup_ins | bigint |
n_tup_upd | bigint |
n_tup_del | bigint |
n_tup_hot_upd | bigint |
n_live_tup | bigint |
n_dead_tup | bigint |
n_mod_since_analyze | bigint |
last_vacuum | timestamp with time zone |
last_autovacuum | timestamp with time zone |
last_analyze | timestamp with time zone |
last_autoanalyze | timestamp with time zone |
vacuum_count | bigint |
autovacuum_count | bigint |
analyze_count | bigint |
autoanalyze_count | bigint |
pg_stat_all_tables (PostgreSQL 9.5)
View "pg_catalog.pg_stat_all_tables"
Column | Type | Modifiers
---------------------+--------------------------+-----------
relid | oid |
schemaname | name |
relname | name |
seq_scan | bigint |
seq_tup_read | bigint |
idx_scan | bigint |
idx_tup_fetch | bigint |
n_tup_ins | bigint |
n_tup_upd | bigint |
n_tup_del | bigint |
n_tup_hot_upd | bigint |
n_live_tup | bigint |
n_dead_tup | bigint |
n_mod_since_analyze | bigint |
last_vacuum | timestamp with time zone |
last_autovacuum | timestamp with time zone |
last_analyze | timestamp with time zone |
last_autoanalyze | timestamp with time zone |
vacuum_count | bigint |
autovacuum_count | bigint |
analyze_count | bigint |
autoanalyze_count | bigint |
pg_stat_all_tables (PostgreSQL 9.4)
View "pg_catalog.pg_stat_all_tables"
Column | Type | Modifiers
---------------------+--------------------------+-----------
relid | oid |
schemaname | name |
relname | name |
seq_scan | bigint |
seq_tup_read | bigint |
idx_scan | bigint |
idx_tup_fetch | bigint |
n_tup_ins | bigint |
n_tup_upd | bigint |
n_tup_del | bigint |
n_tup_hot_upd | bigint |
n_live_tup | bigint |
n_dead_tup | bigint |
n_mod_since_analyze | bigint |
last_vacuum | timestamp with time zone |
last_autovacuum | timestamp with time zone |
last_analyze | timestamp with time zone |
last_autoanalyze | timestamp with time zone |
vacuum_count | bigint |
autovacuum_count | bigint |
analyze_count | bigint |
autoanalyze_count | bigint |
pg_stat_all_tables (PostgreSQL 9.3)
View "pg_catalog.pg_stat_all_tables"
Column | Type | Modifiers
-------------------+--------------------------+-----------
relid | oid |
schemaname | name |
relname | name |
seq_scan | bigint |
seq_tup_read | bigint |
idx_scan | bigint |
idx_tup_fetch | bigint |
n_tup_ins | bigint |
n_tup_upd | bigint |
n_tup_del | bigint |
n_tup_hot_upd | bigint |
n_live_tup | bigint |
n_dead_tup | bigint |
last_vacuum | timestamp with time zone |
last_autovacuum | timestamp with time zone |
last_analyze | timestamp with time zone |
last_autoanalyze | timestamp with time zone |
vacuum_count | bigint |
autovacuum_count | bigint |
analyze_count | bigint |
autoanalyze_count | bigint |
pg_stat_all_tables (PostgreSQL 9.2)
View "pg_catalog.pg_stat_all_tables"
Column | Type | Modifiers
-------------------+--------------------------+-----------
relid | oid |
schemaname | name |
relname | name |
seq_scan | bigint |
seq_tup_read | bigint |
idx_scan | bigint |
idx_tup_fetch | bigint |
n_tup_ins | bigint |
n_tup_upd | bigint |
n_tup_del | bigint |
n_tup_hot_upd | bigint |
n_live_tup | bigint |
n_dead_tup | bigint |
last_vacuum | timestamp with time zone |
last_autovacuum | timestamp with time zone |
last_analyze | timestamp with time zone |
last_autoanalyze | timestamp with time zone |
vacuum_count | bigint |
autovacuum_count | bigint |
analyze_count | bigint |
autoanalyze_count | bigint |
pg_stat_all_tables (PostgreSQL 9.1)
View "pg_catalog.pg_stat_all_tables"
Column | Type | Modifiers
-------------------+--------------------------+-----------
relid | oid |
schemaname | name |
relname | name |
seq_scan | bigint |
seq_tup_read | bigint |
idx_scan | bigint |
idx_tup_fetch | bigint |
n_tup_ins | bigint |
n_tup_upd | bigint |
n_tup_del | bigint |
n_tup_hot_upd | bigint |
n_live_tup | bigint |
n_dead_tup | bigint |
last_vacuum | timestamp with time zone |
last_autovacuum | timestamp with time zone |
last_analyze | timestamp with time zone |
last_autoanalyze | timestamp with time zone |
vacuum_count | bigint |
autovacuum_count | bigint |
analyze_count | bigint |
autoanalyze_count | bigint |
pg_stat_all_tables (PostgreSQL 9.0)
View "pg_catalog.pg_stat_all_tables"
Column | Type | Modifiers
------------------+--------------------------+-----------
relid | oid |
schemaname | name |
relname | name |
seq_scan | bigint |
seq_tup_read | bigint |
idx_scan | bigint |
idx_tup_fetch | bigint |
n_tup_ins | bigint |
n_tup_upd | bigint |
n_tup_del | bigint |
n_tup_hot_upd | bigint |
n_live_tup | bigint |
n_dead_tup | bigint |
last_vacuum | timestamp with time zone |
last_autovacuum | timestamp with time zone |
last_analyze | timestamp with time zone |
last_autoanalyze | timestamp with time zone |
pg_stat_all_tables (PostgreSQL 8.4)
View "pg_catalog.pg_stat_all_tables"
Column | Type | Modifiers
------------------+--------------------------+-----------
relid | oid |
schemaname | name |
relname | name |
seq_scan | bigint |
seq_tup_read | bigint |
idx_scan | bigint |
idx_tup_fetch | bigint |
n_tup_ins | bigint |
n_tup_upd | bigint |
n_tup_del | bigint |
n_tup_hot_upd | bigint |
n_live_tup | bigint |
n_dead_tup | bigint |
last_vacuum | timestamp with time zone |
last_autovacuum | timestamp with time zone |
last_analyze | timestamp with time zone |
last_autoanalyze | timestamp with time zone |
View definition:
SELECT c.oid AS relid, n.nspname AS schemaname, c.relname, pg_stat_get_numscans(c.oid) AS seq_scan, pg_stat_get_tuples_returned(c.oid) AS seq_tup_read, sum(pg_stat_get_numscans(i.indexrelid))::bigint AS idx_scan, sum(pg_stat_get_tuples_fetched(i.indexrelid))::bigint + pg_stat_get_tuples_fetched(c.oid) AS idx_tup_fetch, pg_stat_get_tuples_inserted(c.oid) AS n_tup_ins, pg_stat_get_tuples_updated(c.oid) AS n_tup_upd, pg_stat_get_tuples_deleted(c.oid) AS n_tup_del, pg_stat_get_tuples_hot_updated(c.oid) AS n_tup_hot_upd, pg_stat_get_live_tuples(c.oid) AS n_live_tup, pg_stat_get_dead_tuples(c.oid) AS n_dead_tup, pg_stat_get_last_vacuum_time(c.oid) AS last_vacuum, pg_stat_get_last_autovacuum_time(c.oid) AS last_autovacuum, pg_stat_get_last_analyze_time(c.oid) AS last_analyze, pg_stat_get_last_autoanalyze_time(c.oid) AS last_autoanalyze
FROM pg_class c
LEFT JOIN pg_index i ON c.oid = i.indrelid
LEFT JOIN pg_namespace n ON n.oid = c.relnamespace
WHERE c.relkind = ANY (ARRAY['r'::"char", 't'::"char"])
GROUP BY c.oid, n.nspname, c.relname;
pg_stat_all_tables (PostgreSQL 8.3)
View "pg_catalog.pg_stat_all_tables"
Column | Type | Modifiers
------------------+--------------------------+-----------
relid | oid |
schemaname | name |
relname | name |
seq_scan | bigint |
seq_tup_read | bigint |
idx_scan | bigint |
idx_tup_fetch | bigint |
n_tup_ins | bigint |
n_tup_upd | bigint |
n_tup_del | bigint |
n_tup_hot_upd | bigint |
n_live_tup | bigint |
n_dead_tup | bigint |
last_vacuum | timestamp with time zone |
last_autovacuum | timestamp with time zone |
last_analyze | timestamp with time zone |
last_autoanalyze | timestamp with time zone |
View definition:
SELECT c.oid AS relid, n.nspname AS schemaname, c.relname, pg_stat_get_numscans(c.oid) AS seq_scan, pg_stat_get_tuples_returned(c.oid) AS seq_tup_read, sum(pg_stat_get_numscans(i.indexrelid))::bigint AS idx_scan, sum(pg_stat_get_tuples_fetched(i.indexrelid))::bigint + pg_stat_get_tuples_fetched(c.oid) AS idx_tup_fetch, pg_stat_get_tuples_inserted(c.oid) AS n_tup_ins, pg_stat_get_tuples_updated(c.oid) AS n_tup_upd, pg_stat_get_tuples_deleted(c.oid) AS n_tup_del, pg_stat_get_tuples_hot_updated(c.oid) AS n_tup_hot_upd, pg_stat_get_live_tuples(c.oid) AS n_live_tup, pg_stat_get_dead_tuples(c.oid) AS n_dead_tup, pg_stat_get_last_vacuum_time(c.oid) AS last_vacuum, pg_stat_get_last_autovacuum_time(c.oid) AS last_autovacuum, pg_stat_get_last_analyze_time(c.oid) AS last_analyze, pg_stat_get_last_autoanalyze_time(c.oid) AS last_autoanalyze
FROM pg_class c
LEFT JOIN pg_index i ON c.oid = i.indrelid
LEFT JOIN pg_namespace n ON n.oid = c.relnamespace
WHERE c.relkind = ANY (ARRAY['r'::"char", 't'::"char"])
GROUP BY c.oid, n.nspname, c.relname;
pg_stat_all_tables (PostgreSQL 8.2)
View "pg_catalog.pg_stat_all_tables"
Column | Type | Modifiers
------------------+--------------------------+-----------
relid | oid |
schemaname | name |
relname | name |
seq_scan | bigint |
seq_tup_read | bigint |
idx_scan | bigint |
idx_tup_fetch | bigint |
n_tup_ins | bigint |
n_tup_upd | bigint |
n_tup_del | bigint |
last_vacuum | timestamp with time zone |
last_autovacuum | timestamp with time zone |
last_analyze | timestamp with time zone |
last_autoanalyze | timestamp with time zone |
View definition:
SELECT c.oid AS relid, n.nspname AS schemaname, c.relname, pg_stat_get_numscans(c.oid) AS seq_scan, pg_stat_get_tuples_returned(c.oid) AS seq_tup_read, sum(pg_stat_get_numscans(i.indexrelid))::bigint AS idx_scan, sum(pg_stat_get_tuples_fetched(i.indexrelid))::bigint + pg_stat_get_tuples_fetched(c.oid) AS idx_tup_fetch, pg_stat_get_tuples_inserted(c.oid) AS n_tup_ins, pg_stat_get_tuples_updated(c.oid) AS n_tup_upd, pg_stat_get_tuples_deleted(c.oid) AS n_tup_del, pg_stat_get_last_vacuum_time(c.oid) AS last_vacuum, pg_stat_get_last_autovacuum_time(c.oid) AS last_autovacuum, pg_stat_get_last_analyze_time(c.oid) AS last_analyze, pg_stat_get_last_autoanalyze_time(c.oid) AS last_autoanalyze
FROM pg_class c
LEFT JOIN pg_index i ON c.oid = i.indrelid
LEFT JOIN pg_namespace n ON n.oid = c.relnamespace
WHERE c.relkind = ANY (ARRAY['r'::"char", 't'::"char"])
GROUP BY c.oid, n.nspname, c.relname;
变更历史
- PostgreSQL 19
- 添加了列
stats_reset（提交 a5b54325）
- 添加了列
- PostgreSQL 18
- 添加了以下列 (提交 30a6ed0c)
total_vacuum_timetotal_autovacuum_timetotal_analyze_timetotal_autoanalyze_time
- 添加了以下列 (提交 30a6ed0c)
- PostgreSQL 16
- PostgreSQL 13
- 添加了列
n_ins_since_vacuum(提交 b07642db)
- 添加了列
- PostgreSQL 9.4
- 添加了列
n_mod_since_analyze(提交 c87ff71f)
- 添加了列
- PostgreSQL 9.1
- 添加了以下列 (提交 946045f0)
vacuum_countautovacuum_countanalyze_countautoanalyze_count
- 添加了以下列 (提交 946045f0)
- PostgreSQL 8.3
- PostgreSQL 7.2
- 添加 (提交 8d80b0d9)
注意: 8.3 版本之前的任何更改在此处均未注明。
参考资料
- PostgreSQL 文档: pg_stat_all_tables
有用链接
- PostgreSQL 高效监控：在 PostgreSQL 16 中利用 pg_stat_all_tables 和 pg_stat_all_indexes 视图 - Dave Page / EnterpriseDB 的 2023 年 7 月博客文章
- 深入解析 PostgreSQL 统计信息：pg_stat_all_tables - Alexey Lesovsky 的 2017 年 4 月博客文章