我从Oracle来到Postgres,寻找一种方法来查找表和索引大小的字节/MB/GB/等,甚至更好的所有表的大小。在Oracle中,我有一个讨厌的长查询,查看user_lobs和user_segments以返回一个答案。
我假设在Postgres中有一些东西我可以在information_schema表中使用,但我不知道在哪里。
我从Oracle来到Postgres,寻找一种方法来查找表和索引大小的字节/MB/GB/等,甚至更好的所有表的大小。在Oracle中,我有一个讨厌的长查询,查看user_lobs和user_segments以返回一个答案。
我假设在Postgres中有一些东西我可以在information_schema表中使用,但我不知道在哪里。
当前回答
试试这个脚本来查找所有表的大小:
SELECT
table_schema || '.' || table_name AS TableName,
pg_size_pretty(pg_total_relation_size('"' || table_schema || '"."' || table_name || '"')) AS TableSize
FROM information_schema.tables
ORDER BY
pg_total_relation_size('"' || table_schema || '"."' || table_name || '"') DESC
对于PostgreSQL中其他不同的脚本,请访问这个url: http://www.dbrnd.com/2015/05/how-to-find-size-of-database-and-table-in-postgresql/
其他回答
试试数据库对象大小函数。一个例子:
SELECT pg_size_pretty(pg_total_relation_size('"<schema>"."<table>"'));
对于所有表,如下所示:
SELECT
table_schema || '.' || table_name AS table_full_name,
pg_size_pretty(pg_total_relation_size('"' || table_schema || '"."' || table_name || '"')) AS size
FROM information_schema.tables
ORDER BY
pg_total_relation_size('"' || table_schema || '"."' || table_name || '"') DESC;
编辑:为了方便起见,下面是@phord提交的查询:
SELECT
table_name,
pg_size_pretty(table_size) AS table_size,
pg_size_pretty(indexes_size) AS indexes_size,
pg_size_pretty(total_size) AS total_size
FROM (
SELECT
table_name,
pg_table_size(table_name) AS table_size,
pg_indexes_size(table_name) AS indexes_size,
pg_total_relation_size(table_name) AS total_size
FROM (
SELECT ('"' || table_schema || '"."' || table_name || '"') AS table_name
FROM information_schema.tables
) AS all_tables
ORDER BY total_size DESC
) AS pretty_sizes;
我稍微修改了一下,使用pg_table_size()来包含元数据并使大小相加。
试试这个脚本来查找所有表的大小:
SELECT
table_schema || '.' || table_name AS TableName,
pg_size_pretty(pg_total_relation_size('"' || table_schema || '"."' || table_name || '"')) AS TableSize
FROM information_schema.tables
ORDER BY
pg_total_relation_size('"' || table_schema || '"."' || table_name || '"') DESC
对于PostgreSQL中其他不同的脚本,请访问这个url: http://www.dbrnd.com/2015/05/how-to-find-size-of-database-and-table-in-postgresql/
PostgreSQL表有三个组件:表本身、表上的索引以及潜在的TOAST数据。在http://wiki.postgresql.org/wiki/Disk_Usage上有几个例子展示了如何以各种方式滑动和切割可用信息
试试这个:(索引大小/使用统计)
SELECT
t.tablename,
indexname,
c.reltuples AS num_rows,
pg_size_pretty(pg_relation_size(quote_ident(t.tablename)::text)) AS table_size,
pg_size_pretty(pg_relation_size(quote_ident(indexrelname)::text)) AS index_size,
CASE WHEN indisunique THEN 'Y'
ELSE 'N'
END AS UNIQUE,
idx_scan AS number_of_scans,
idx_tup_read AS tuples_read,
idx_tup_fetch AS tuples_fetched
FROM pg_tables t
LEFT OUTER JOIN pg_class c ON t.tablename=c.relname
LEFT OUTER JOIN
( SELECT c.relname AS ctablename, ipg.relname AS indexname, x.indnatts AS number_of_columns, idx_scan, idx_tup_read, idx_tup_fetch, indexrelname, indisunique FROM pg_index x
JOIN pg_class c ON c.oid = x.indrelid
JOIN pg_class ipg ON ipg.oid = x.indexrelid
JOIN pg_stat_all_indexes psai ON x.indexrelid = psai.indexrelid )
AS foo
ON t.tablename = foo.ctablename
WHERE t.schemaname='public'
ORDER BY 1,2;
查看这个维基。https://wiki.postgresql.org/wiki/Disk_Usage
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