如何找到 Postgres / PostgreSQL 表及其索引的磁盘大小

Question

我从 Oracle 来到 Postgres 并寻找一种方法来查找表和索引大小（以bytes/MB/GB/etc ，甚至更好的所有表的大小）。 在 Oracle 中，我有一个令人讨厌的长查询，它查看 user_lobs 和 user_segments 以给出答案。

我假设在 Postgres 中有一些我可以在information_schema表中使用的东西，但我没有看到在哪里。

Answer 1

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>"'));

对于所有表格，大致如下：

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：这是@phord 提交的查询，为方便起见：

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;

我稍微修改了它以使用pg_table_size()来包含元数据并使大小相加。

Answer 2

显示数据库大小：

\\l+

例如

=> \l+
 berbatik_prd_commerce    | berbatik_prd     | UTF8     | en_US.UTF-8 | en_US.UTF-8 |                       | 19 MB   | pg_default | 
 berbatik_stg_commerce    | berbatik_stg     | UTF8     | en_US.UTF-8 | en_US.UTF-8 |                       | 8633 kB | pg_default | 
 bursasajadah_prd         | bursasajadah_prd | UTF8     | en_US.UTF-8 | en_US.UTF-8 |                       | 1122 MB | pg_default | 

显示桌子尺寸：

\\d+

例如

=> \d+
 public | tuneeca_prd | table | tomcat | 8192 bytes | 
 public | tuneeca_stg | table | tomcat | 1464 kB    | 

仅适用于psql 。

（ @zkutch 的回答摘要。）

Answer 3

如果数据库名称为snort ，则以下语句为其指定大小：

psql -c "\l+ snort" | awk -F "|" '{print $7}'

Answer 4

Tyr this :(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;

Answer 5

PostgreSQL 表具有三个组成部分：表本身、其上的任何索引，以及潜在的 TOAST 数据。 有几个例子展示了如何在http://wiki.postgresql.org/wiki/Disk_Usage 以各种方式滑动和切块可用信息

Answer 6

仅供参考，我从@aib 那里得到了很好的答案，并对其进行了一些修改：

• 仅从“公共”模式中获取表
• 还显示物化视图数据和索引大小

在物化视图上，我们可以使用索引同时刷新物化视图，这允许在更新时使用它们。

好吧，我的查询如下：

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 (
        -- tables from 'public'
        SELECT table_name
        FROM information_schema.tables
        where table_schema = 'public' and table_type = 'BASE TABLE'
        union
        -- materialized views
        SELECT oid::regclass::text as table_name
        FROM pg_class
        WHERE relkind = 'm'
        order by table_name
    ) AS all_tables
    -- ORDER BY total_size DESC
    order by table_name
) AS pretty_sizes

Answer 7

下面的查询将为您服务

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
LIMIT 20;

请参阅此链接： https : //wiki.postgresql.org/wiki/Disk_Usage

Answer 8

检查这个维基。 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

Answer 9

尝试使用此脚本查找所有表大小：

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

对于在 PostgreSQL 中查找大小的其他不同脚本，请访问此 URL： http : //www.dbrnd.com/2015/05/how-to-find-size-of-database-and-table-in-postgresql/