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这篇文章主要讲解了“PostgreSQL 中关于 xid freeze 的脚本有哪些”，文中的讲解内容简单清晰，易于学习与理解，下面请大家跟着丸趣 TV 小编的思路慢慢深入，一起来研究和学习“PostgreSQL 中关于 xid freeze 的脚本有哪些”吧！
Monitor Database
数据库监控脚本
[local:/data/run/pg12]:5120 pg12@testdb=# show autovacuum_freeze_max_age;
autovacuum_freeze_max_age
---------------------------
200000000
(1 row)
[local:/data/run/pg12]:5120 pg12@testdb=# WITH max_age AS (
pg12@testdb(# SELECT 2000000000 as max_old_xid
pg12@testdb(# , setting AS autovacuum_freeze_max_age
pg12@testdb(# FROM pg_catalog.pg_settings
pg12@testdb(# WHERE name = autovacuum_freeze_max_age )
pg12@testdb-# , per_database_stats AS (
pg12@testdb(# SELECT datname
pg12@testdb(# , m.max_old_xid::int
pg12@testdb(# , m.autovacuum_freeze_max_age::int
pg12@testdb(# , age(d.datfrozenxid) AS oldest_current_xid
pg12@testdb(# FROM pg_catalog.pg_database d
pg12@testdb(# JOIN max_age m ON (true)
pg12@testdb(# WHERE d.datallowconn )
pg12@testdb-# SELECT max(oldest_current_xid) AS oldest_current_xid
pg12@testdb-# , max(ROUND(100*(oldest_current_xid/max_old_xid::float))) AS percent_towards_wraparound
pg12@testdb-# , max(ROUND(100*(oldest_current_xid/autovacuum_freeze_max_age::float))) AS percent_towards_emergency_autovac
pg12@testdb-# FROM per_database_stats;
oldest_current_xid | percent_towards_wraparound | percent_towards_emergency_autovac
--------------------+----------------------------+-----------------------------------
3844 | 0 | 0
(1 row)
[local:/data/run/pg12]:5120 pg12@testdb=#percent_towards_wraparound= 数据库年龄 /20 亿，如接近 100%，那么需要特别注意；
percent_towards_emergency_autovac= 数据库年龄 /autovacuum_freeze_max_age，autovacuum_freeze_max_age 参数一般为 2 亿。
下面的脚本列出了每个数据库的年龄和 autovacuum_freeze_max_age 参数的设定。
[local:/data/run/pg12]:5120 pg12@testdb=# SELECT datname
pg12@testdb-# , age(datfrozenxid)
pg12@testdb-# , current_setting(autovacuum_freeze_max_age)
pg12@testdb-# FROM pg_database
pg12@testdb-# ORDER BY 2 DESC;
datname | age | current_setting
-----------+------+-----------------
postgres | 3844 | 200000000
template1 | 3844 | 200000000
template0 | 3844 | 200000000
db1 | 3844 | 200000000
db2 | 3844 | 200000000
db3 | 3844 | 200000000
testdb | 3844 | 200000000
(7 rows)Monitor relation
监控关系（数据表）
[local:/data/run/pg12]:5120 pg12@testdb=# SELECT c.oid::regclass
pg12@testdb-# , age(c.relfrozenxid)
pg12@testdb-# , pg_size_pretty(pg_total_relation_size(c.oid))
pg12@testdb-# FROM pg_class c
pg12@testdb-# JOIN pg_namespace n on c.relnamespace = n.oid
pg12@testdb-# WHERE relkind IN (r , t , m)
pg12@testdb-# AND n.nspname NOT IN (pg_toast)
pg12@testdb-# ORDER BY 2 DESC LIMIT 100;
oid | age | pg_size_pretty
--------------------------------------------+------+----------------
pg_policy | 3844 | 24 kB
pg_init_privs | 3844 | 72 kB
pg_seclabel | 3844 | 16 kB
pg_shseclabel | 3844 | 16 kB
pg_collation | 3844 | 384 kB
pg_partitioned_table | 3844 | 16 kB
pg_range | 3844 | 56 kB
pg_transform | 3844 | 16 kB
pg_sequence | 3844 | 8192 bytes
pg_publication | 3844 | 16 kB
pg_publication_rel | 3844 | 16 kB
pg_subscription_rel | 3844 | 8192 bytes
information_schema.sql_packages | 3844 | 48 kB
information_schema.sql_features | 3844 | 104 kB
information_schema.sql_implementation_info | 3844 | 48 kB
information_schema.sql_parts | 3844 | 48 kB
information_schema.sql_languages | 3844 | 48 kB
information_schema.sql_sizing | 3844 | 48 kB
pg_statistic | 3844 | 312 kB
pg_type | 3844 | 192 kB
pg_foreign_server | 3844 | 24 kB
pg_authid | 3844 | 48 kB
pg_statistic_ext_data | 3844 | 16 kB
--More--以上列出了每个 relation 的 age 以及 relation 的大小。
Auto Generate Script
该脚本自动创建清理脚本。
[local:/data/run/pg12]:5120 pg12@testdb=# \t
Tuples only is on.
[local:/data/run/pg12]:5120 pg12@testdb=# \o /tmp/vacuum.sql
[local:/data/run/pg12]:5120 pg12@testdb=# select vacuum freeze analyze verbose || oid::regclass || from pg_class where relkind in (r , t , m) order by age(relfrozenxid) desc limit 100;
[local:/data/run/pg12]:5120 pg12@testdb=# \o
[local:/data/run/pg12]:5120 pg12@testdb=# \t
Tuples only is off.
[local:/data/run/pg12]:5120 pg12@testdb=# \set ECHO all
[local:/data/run/pg12]:5120 pg12@testdb=# \! cat /tmp/vacuum.sql
vacuum freeze analyze verbose pg_ts_parser;
vacuum freeze analyze verbose pg_collation;
vacuum freeze analyze verbose pg_partitioned_table;
vacuum freeze analyze verbose pg_range;
vacuum freeze analyze verbose pg_transform;
vacuum freeze analyze verbose pg_sequence;
vacuum freeze analyze verbose pg_publication;
vacuum freeze analyze verbose pg_publication_rel;
vacuum freeze analyze verbose pg_subscription_rel;
vacuum freeze analyze verbose information_schema.sql_packages;
vacuum freeze analyze verbose pg_toast.pg_toast_13426;
vacuum freeze analyze verbose information_schema.sql_features;
vacuum freeze analyze verbose pg_toast.pg_toast_13431;
vacuum freeze analyze verbose pg_toast.pg_toast_13446;
vacuum freeze analyze verbose information_schema.sql_implementation_info;
vacuum freeze analyze verbose pg_toast.pg_toast_13436;
vacuum freeze analyze verbose information_schema.sql_parts;
vacuum freeze analyze verbose information_schema.sql_languages;
vacuum freeze analyze verbose pg_toast.pg_toast_13441;
vacuum freeze analyze verbose information_schema.sql_sizing;
vacuum freeze analyze verbose pg_toast.pg_toast_13451;
vacuum freeze analyze verbose pg_statistic;
vacuum freeze analyze verbose pg_type;
vacuum freeze analyze verbose pg_toast.pg_toast_2600;
vacuum freeze analyze verbose pg_toast.pg_toast_2604;
vacuum freeze analyze verbose pg_toast.pg_toast_3456;
vacuum freeze analyze verbose pg_toast.pg_toast_2606;
vacuum freeze analyze verbose pg_toast.pg_toast_826;
vacuum freeze analyze verbose pg_toast.pg_toast_2609;
vacuum freeze analyze verbose pg_toast.pg_toast_3466;
vacuum freeze analyze verbose pg_toast.pg_toast_3079;
vacuum freeze analyze verbose pg_toast.pg_toast_2328;
vacuum freeze analyze verbose pg_toast.pg_toast_1417;
vacuum freeze analyze verbose pg_toast.pg_toast_3118;
vacuum freeze analyze verbose pg_toast.pg_toast_3394;
vacuum freeze analyze verbose pg_toast.pg_toast_2612;
vacuum freeze analyze verbose pg_toast.pg_toast_2615;
vacuum freeze analyze verbose pg_foreign_server;
vacuum freeze analyze verbose pg_toast.pg_toast_3350;
vacuum freeze analyze verbose pg_toast.pg_toast_3256;
vacuum freeze analyze verbose pg_toast.pg_toast_1255;
vacuum freeze analyze verbose pg_toast.pg_toast_2618;
vacuum freeze analyze verbose pg_toast.pg_toast_3596;
vacuum freeze analyze verbose pg_toast.pg_toast_2619;
vacuum freeze analyze verbose pg_toast.pg_toast_3381;
vacuum freeze analyze verbose pg_toast.pg_toast_3429;
vacuum freeze analyze verbose pg_toast.pg_toast_2620;
vacuum freeze analyze verbose pg_toast.pg_toast_3600;
vacuum freeze analyze verbose pg_toast.pg_toast_1247;
vacuum freeze analyze verbose pg_toast.pg_toast_1418;
vacuum freeze analyze verbose pg_toast.pg_toast_1260;
vacuum freeze analyze verbose pg_toast.pg_toast_1262;
vacuum freeze analyze verbose pg_toast.pg_toast_2964;
vacuum freeze analyze verbose pg_toast.pg_toast_1136;
vacuum freeze analyze verbose pg_toast.pg_toast_6000;
vacuum freeze analyze verbose pg_toast.pg_toast_2396;
vacuum freeze analyze verbose pg_toast.pg_toast_3592;
vacuum freeze analyze verbose pg_toast.pg_toast_6100;
vacuum freeze analyze verbose pg_toast.pg_toast_1213;
vacuum freeze analyze verbose pg_authid;
vacuum freeze analyze verbose pg_statistic_ext_data;
vacuum freeze analyze verbose pg_user_mapping;
vacuum freeze analyze verbose pg_subscription;
vacuum freeze analyze verbose pg_attribute;
vacuum freeze analyze verbose pg_proc;
vacuum freeze analyze verbose pg_class;
vacuum freeze analyze verbose pg_attrdef;
vacuum freeze analyze verbose pg_constraint;
vacuum freeze analyze verbose pg_inherits;
vacuum freeze analyze verbose pg_index;
vacuum freeze analyze verbose pg_operator;
vacuum freeze analyze verbose pg_opfamily;
vacuum freeze analyze verbose pg_opclass;
vacuum freeze analyze verbose pg_am;
vacuum freeze analyze verbose pg_amop;
vacuum freeze analyze verbose pg_amproc;
vacuum freeze analyze verbose pg_language;
vacuum freeze analyze verbose pg_largeobject_metadata;
vacuum freeze analyze verbose pg_aggregate;
vacuum freeze analyze verbose pg_largeobject;
vacuum freeze analyze verbose pg_statistic_ext;
vacuum freeze analyze verbose pg_rewrite;
vacuum freeze analyze verbose pg_trigger;
vacuum freeze analyze verbose pg_event_trigger;
vacuum freeze analyze verbose pg_description;
vacuum freeze analyze verbose pg_cast;
vacuum freeze analyze verbose pg_enum;
vacuum freeze analyze verbose pg_namespace;
vacuum freeze analyze verbose pg_conversion;
vacuum freeze analyze verbose pg_depend;
vacuum freeze analyze verbose pg_database;
vacuum freeze analyze verbose pg_db_role_setting;
vacuum freeze analyze verbose pg_tablespace;
vacuum freeze analyze verbose pg_pltemplate;
vacuum freeze analyze verbose pg_auth_members;
vacuum freeze analyze verbose pg_shdepend;
vacuum freeze analyze verbose pg_shdescription;
vacuum freeze analyze verbose pg_ts_config;
vacuum freeze analyze verbose pg_ts_config_map;
vacuum freeze analyze verbose pg_ts_dict;
[local:/data/run/pg12]:5120 pg12@testdb=#感谢各位的阅读，以上就是“PostgreSQL 中关于 xid freeze 的脚本有哪些”的内容了，经过本文的学习后，相信大家对 PostgreSQL 中关于 xid freeze 的脚本有哪些这一问题有了更深刻的体会，具体使用情况还需要大家实践验证。这里是丸趣 TV，丸趣 TV 小编将为大家推送更多相关知识点的文章，欢迎关注！
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