¿Cómo encuentra el tamaño de disco de una tabla Postgres / PostgreSQL y sus índices?

Estoy llegando a Postgres desde Oracle y estoy buscando una manera de encontrar la tabla y el tamaño del índice en términos de bytes/MB/GB/etc, o incluso mejor, el tamaño de todas las tablas. En Oracle tuve una consulta larga y desagradable que analizaba user_lobs y user_segments para devolver una respuesta.

Supongo que en Postgres hay algo que puedo usar en las information_schematablas, pero no veo dónde.

Pruebe las funciones de tamaño de objeto de base de datos . Un ejemplo:

SELECT pg_size_pretty(pg_total_relation_size('"<schema>"."<table>"'));

Para todas las tablas, algo en la línea de:

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;

Editar: Aquí está la consulta enviada por @phord, por conveniencia:

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;

Lo modifiqué un poco para usarlo pg_table_size()para incluir metadatos y hacer que los tamaños se sumen.

Mostrar tamaños de base de datos:

\l+

p.ej

=> \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 | 

Mostrar tamaños de mesa:

\d+

p.ej

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

Solo funciona en psql.

(Resumen de la respuesta de @ zkutch ).

Si el nombre de la base de datos es snort, la siguiente oración le da tamaño:

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

Tyr esto: (Tamaño del índice / estadísticas de uso)

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;

Las tablas PostgreSQL tienen tres componentes: la tabla en sí, cualquier índice que contenga y, posiblemente, los datos de TOAST. Hay un par de ejemplos que muestran cómo deslizar y cortar la información disponible de varias maneras en http://wiki.postgresql.org/wiki/Disk_Usage

Solo para información, recibí la excelente respuesta de @aib y la modifiqué un poco para:

• obteniendo solo tablas del esquema "público"
• mostrar también datos de vistas materializadas y tamaño de índice

En la vista materializada, podemos usar el índice para actualizar las vistas materializadas simultáneamente , lo que permite usarlas durante la actualización.

Bueno, mi consulta será la siguiente:

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

La consulta a continuación le servirá

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;

Ver este enlace: https://wiki.postgresql.org/wiki/Disk_Usage

mira esta wiki https://wiki.postgresql.org/wiki/Disk_Usage

SELECT *, pg_size_pretty (total_bytes) AS total
    , pg_size_pretty (index_bytes) COMO ÍNDICE
    , pg_size_pretty (toast_bytes) AS brindis
    , pg_size_pretty (table_bytes) COMO TABLA
  DE (
  SELECT *, total_bytes-index_bytes-COALESCE (toast_bytes, 0) AS table_bytes FROM (
      SELECCIONE 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
          DE pg_class c
          IZQUIERDA UNIRSE pg_namespace n ON n.oid = c.relnamespace
          DONDE relkind = 'r'
  ) una
) una

Pruebe este script para encontrar todos los tamaños de tabla:

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

Para ver otro script diferente para encontrar el tamaño en PostgreSQL, visite esta url: http://www.dbrnd.com/2015/05/how-to-find-size-of-database-and-table-in-postgresql/