如何列出PostgreSQL 数据库的所有表并按大小排序?
11 回答
select table_name, pg_relation_size(quote_ident(table_name))
from information_schema.tables
where table_schema = 'public'
order by 2
如果您有多个模式,这将向您显示模式中所有表的大小public
,您可能希望使用:
select table_schema, table_name, pg_relation_size('"'||table_schema||'"."'||table_name||'"')
from information_schema.tables
order by 3
SQLFiddle 示例:http ://sqlfiddle.com/#!15/13157/3
手册中所有对象大小函数的列表。
这将向您显示架构名称、表名、大小和大小(排序所需)。
SELECT
schema_name,
relname,
pg_size_pretty(table_size) AS size,
table_size
FROM (
SELECT
pg_catalog.pg_namespace.nspname AS schema_name,
relname,
pg_relation_size(pg_catalog.pg_class.oid) AS table_size
FROM pg_catalog.pg_class
JOIN pg_catalog.pg_namespace ON relnamespace = pg_catalog.pg_namespace.oid
) t
WHERE schema_name NOT LIKE 'pg_%'
ORDER BY table_size DESC;
这会更清楚。
pg_size_pretty(<numeric_value>)
- 将字节数转换为人类可读的格式。
pg_database_size(<db_name>)
- 以字节为单位获取数据库大小。
pg_total_relation_size(<relation_name>)
- 获取表的总大小及其索引(以字节为单位)。
pg_relation_size(<relation_name>)
- 以字节为单位获取关系(表/索引)大小。
pg_index_size(<relation_name>)
- 获取关系的索引大小(以字节为单位)。
current_database()
- 获取正在执行此查询的当前使用的数据库。
询问:
select current_database() as database,
pg_size_pretty(total_database_size) as total_database_size,
schema_name,
table_name,
pg_size_pretty(total_table_size) as total_table_size,
pg_size_pretty(table_size) as table_size,
pg_size_pretty(index_size) as index_size
from ( select table_name,
table_schema as schema_name,
pg_database_size(current_database()) as total_database_size,
pg_total_relation_size(table_name) as total_table_size,
pg_relation_size(table_name) as table_size,
pg_indexes_size(table_name) as index_size
from information_schema.tables
where table_schema=current_schema() and table_name like 'table_%'
order by total_table_size
) as sizes;
结果:
database | total_database_size | schema_name | table_name | total_table_size | table_size | index_size
-----------+---------------------+-------------+------------+------------------+------------+------------
vigneshdb | 1586 MB | corpdata | table_aaa | 16 kB | 0 bytes | 8192 bytes
vigneshdb | 1586 MB | corpdata | table_bbb | 24 kB | 0 bytes | 16 kB
vigneshdb | 1586 MB | corpdata | table_ccc | 640 kB | 112 kB | 488 kB
vigneshdb | 1586 MB | corpdata | table_ddd | 9760 kB | 3152 kB | 6568 kB
vigneshdb | 1586 MB | corpdata | table_eee | 1120 MB | 311 MB | 808 MB
人性化格式以bytes
、kB
、MB
、GB
和表示TB
。
bytes
到kB
- 开始于10240 bytes
bytes
to MB
- 从10485248 bytes
= 10239.5 kB
~开始10 MB
bytes
to GB
- 从10736893952 bytes
= 10239.5 MB
~开始10 BG
bytes
to TB
- 从10994579406848 bytes
= 10239.5 GB
~开始10 TB
所有单位转换从10 + <unit>
.
供参考 - Postgres 官方文档
SELECT
relname as "Table",
pg_size_pretty(pg_total_relation_size(relid)) As "Size",
pg_size_pretty(pg_total_relation_size(relid) - pg_relation_size(relid)) as "External Size"
FROM pg_catalog.pg_statio_user_tables ORDER BY pg_total_relation_size(relid) DESC;
取自这里https://wiki-bsse.ethz.ch/display/ITDOC/Check+size+of+tables+and+objects+in+PostgreSQL+database
我需要找出哪些表使用的空间最多。
根据其他答案,我使用了该查询:
select table_name, pg_size_pretty( pg_relation_size(quote_ident(table_name)) )
from information_schema.tables
where table_schema = 'public'
order by pg_relation_size(quote_ident(table_name)) desc
我得到以下结果:
table_name pg_size_pretty
--------------------------------------
trade_binance 96 GB
closs_v2_binance_stash 46 GB
closs_bitfinex_stash 5725 MB
trade_bitfinex 5112 MB
...
api_requests 0 bytes
trade_huobi 0 bytes
我应该买一个更大的SSD。
我喜欢下面的陈述:
SELECT
table_name,
pg_size_pretty( pg_total_relation_size(quote_ident(table_name))),
pg_total_relation_size(quote_ident(table_name))
FROM
information_schema.tables
WHERE
table_schema = 'public'
ORDER BY
pg_total_relation_size(quote_ident(table_name)) DESC
您可以以漂亮的格式查看总尺寸,但它的排序也正确。
select table_name,n_live_tup, pg_size_pretty(pg_relation_size(table_name))
from information_schema.tables
inner join pg_stat_user_tables on table_name=relname
where table_schema = 'public'
order by 2 desc
另一种选择
SELECT nspname || '.' || relname AS "relation",
pg_size_pretty(pg_total_relation_size(C.oid)) AS "total_size"
FROM pg_class C
LEFT JOIN pg_namespace N ON (N.oid = C.relnamespace)
WHERE nspname NOT IN ('pg_catalog', 'information_schema')
AND C.relkind <> 'i'
AND nspname !~ '^pg_toast'
ORDER BY pg_total_relation_size(C.oid) DESC
;
信用: https ://makandracards.com/makandra/52141-postgresql-how-to-show-table-sizes
select uv.a tablename, pg_size_pretty(uv.b) sizepretty
from (select tb.tablename a, pg_table_size('schemaname.'||tb.tablename::text) b
from pg_tables tb
where tb.schemaname ilike 'schemaname'
order by 2 desc
) uv
select table_name, pg_size_pretty(pg_total_relation_size(quote_ident(table_name)))
from information_schema.tables
where table_schema = 'public'
order by pg_total_relation_size(quote_ident(table_name));
pg_total_relation_size
将包括索引和表的大小。如果您只想要表格大小,那就pg_relation_size
足够了。
如果您正在寻找总的细分,toast 和 index 大小使用这个:
SELECT *, pg_size_pretty(total_bytes) AS total
, pg_size_pretty(index_bytes) AS INDEX
, pg_size_pretty(toast_bytes) AS toast
, pg_size_pretty(table_bytes) AS TABLE
FROM (
SELECT *, total_bytes-index_bytes-COALESCE(toast_bytes,0) AS table_bytes
FROM (
SELECT c.oid,nspname AS table_schema, relname AS TABLE_NAME
, c.reltuples AS row_estimate
, pg_total_relation_size(c.oid) AS total_bytes
, pg_indexes_size(c.oid) AS index_bytes
, pg_total_relation_size(reltoastrelid) AS toast_bytes
FROM pg_class c
LEFT JOIN pg_namespace n ON n.oid = c.relnamespace
WHERE relkind = 'r'
) a
) a ORDER BY total_bytes DESC;