Je viens d’Oracle chez Postgres et je cherche un moyen de trouver la taille de la table et de l’index en termes d’octets/Mo/Go/etc., voire d’améliorer la taille de toutes les tables. Dans Oracle, j'avais une longue et méchante requête qui examinait user_lobs et user_segments pour donner une réponse. Je suppose que dans Postgres, je peux utiliser quelque chose dans les tables information_schema, mais je ne vois pas où. Merci d'avance.
Essayez les fonctions Database Object Size . Un exemple:
SELECT pg_size_pretty(pg_total_relation_size('"<schema>"."<table>"'));
Pour toutes les tables, quelque chose comme:
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;
Edit: Voici la requête soumise par @phord, pour plus de commodité:
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;
Je l'ai légèrement modifié pour utiliser pg_table_size()
pour inclure des métadonnées et faire en sorte que les tailles s'additionnent.
Afficher les tailles de base de données:
\l+
par exemple.
=> \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 |
Afficher les tailles de table:
\d+
par exemple.
=> \d+
public | tuneeca_prd | table | Tomcat | 8192 bytes |
public | tuneeca_stg | table | Tomcat | 1464 kB |
Ne fonctionne que dans psql
.
(Résumé de la réponse de @ zkutch .)
Si le nom de la base de données est snort
, la phrase suivante lui donne la taille:
psql snort -c "\l+" | grep snort | awk -F "|" '{print $7}'
Les tables PostgreSQL ont trois composants: la table elle-même, ses index et éventuellement les données TOAST. Quelques exemples montrent comment glisser et dés les informations disponibles de différentes manières sur http://wiki.postgresql.org/wiki/Disk_Usage
Tyr this: (taille de l’index/statistiques d’utilisation)
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;
Juste pour info, j'ai reçu l'excellente réponse de @aib et l'ai modifiée un peu pour:
Sur une vue matérialisée, nous pouvons utiliser index pour actualiser les vues matérialisées simultanément , ce qui permet de les utiliser lors de la mise à jour.
Eh bien, ma requête sera la suivante:
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
consultez ce wiki. 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 schema_table, nom_relatif AS NOM_SEMBLE 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 relnamespace WHERE relkind = 'r' ) a ) a
La requête ci-dessous vous servira
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;
Voir ce lien: https://wiki.postgresql.org/wiki/Disk_Usage