Listar todos los nombres de índice, columnas y su nombre de tabla de una base de datos PostgreSQL

Question

¿Cuál es la consulta para obtener la lista de todos los nombres de índice, su nombre de columna y su nombre de tabla de una base de datos postgresql?

He intentado obtener la lista de todos los índices en una base de datos utilizando esta consulta, pero ¿cómo obtener la lista de índices, sus nombres de columna y sus nombres de tabla?

SELECT * 
FROM pg_class, pg_index 
WHERE pg_class.oid = pg_index.indexrelid 
AND pg_class.oid IN (
    SELECT indexrelid 
    FROM pg_index, pg_class 
    WHERE pg_class.oid=pg_index.indrelid 
    AND indisunique != 't' 
    AND indisprimary != 't' 
    AND relname !~ '^pg_');` 

Answer 1

Esta es la salida de todos los índices con detalles (extraído de mis definiciones de vista):

SELECT i.relname as indname, 
     i.relowner as indowner, 
     idx.indrelid::regclass, 
     am.amname as indam, 
     idx.indkey, 
     ARRAY(
     SELECT pg_get_indexdef(idx.indexrelid, k + 1, true) 
     FROM generate_subscripts(idx.indkey, 1) as k 
     ORDER BY k 
     ) as indkey_names, 
     idx.indexprs IS NOT NULL as indexprs, 
     idx.indpred IS NOT NULL as indpred 
FROM pg_index as idx 
JOIN pg_class as i 
ON  i.oid = idx.indexrelid 
JOIN pg_am as am 
ON  i.relam = am.oid; 

Opcionalmente añadir un extra de unirse a la final con el fin de recortar los espacios de nombres:

SELECT i.relname as indname, 
     i.relowner as indowner, 
     idx.indrelid::regclass, 
     am.amname as indam, 
     idx.indkey, 
     ARRAY(
     SELECT pg_get_indexdef(idx.indexrelid, k + 1, true) 
     FROM generate_subscripts(idx.indkey, 1) as k 
     ORDER BY k 
     ) as indkey_names, 
     idx.indexprs IS NOT NULL as indexprs, 
     idx.indpred IS NOT NULL as indpred 
FROM pg_index as idx 
JOIN pg_class as i 
ON  i.oid = idx.indexrelid 
JOIN pg_am as am 
ON  i.relam = am.oid 
JOIN pg_namespace as ns 
ON  ns.oid = i.relnamespace 
AND ns.nspname = ANY(current_schemas(false)); 

Answer 2

Versión más amigable de la solución @Denis:

SELECT 
    U.usename    AS user_name, 
    ns.nspname    AS schema_name, 
    idx.indrelid :: REGCLASS AS table_name, 
    i.relname    AS index_name, 
    idx.indisunique   AS is_unique, 
    idx.indisprimary   AS is_primary, 
    am.amname    AS index_type, 
    idx.indkey, 
     ARRAY(
      SELECT pg_get_indexdef(idx.indexrelid, k + 1, TRUE) 
      FROM 
      generate_subscripts(idx.indkey, 1) AS k 
      ORDER BY k 
     ) AS index_keys, 
    (idx.indexprs IS NOT NULL) OR (idx.indkey::int[] @> array[0]) AS is_functional, 
    idx.indpred IS NOT NULL AS is_partial 
FROM pg_index AS idx 
    JOIN pg_class AS i 
    ON i.oid = idx.indexrelid 
    JOIN pg_am AS am 
    ON i.relam = am.oid 
    JOIN pg_namespace AS NS ON i.relnamespace = NS.OID 
    JOIN pg_user AS U ON i.relowner = U.usesysid 
WHERE NOT nspname LIKE 'pg%'; -- Excluding system tables 

Answer 3

la consulta para una lista de todos los índices de una base de datos

SELECT 
    tablename, 
    indexes [1], 
    indexes [2], 
    indexes [3], 
    indexes [4], 
    indexes [5], 
    indexes [6], 
    indexes [7], 
    indexes [8], 
    indexes [9], 
    indexes [10] 
FROM (SELECT 
    tablename, 
    array_agg(indexname) AS indexes 
FROM pg_indexes 
WHERE schemaname = 'public' 
GROUP BY tablename) as sub; 

Answer 4

Si también está interesado en el tamaño del índice , es posible utilizar esta consulta desde el PostgreSQL Wiki.

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

Aquí hay una versión que simplifica las cosas en comparación con otras respuestas por

• evitando selecciona anidados
• evitando funciones integradas (tal vez difícil de recordar)
• utilizando impresionantes LATERAL y UNNEST(...) WITH ORDINALITY características disponible en versiones posteriores de PostgreSQL (9.4+)

SELECT 
    tnsp.nspname AS schema_name, 
    trel.relname AS table_name, 
    irel.relname AS index_name, 
    array_agg (a.attname ORDER BY c.ordinality) AS columns 
FROM pg_index AS i 
JOIN pg_class AS trel ON trel.oid = i.indrelid 
JOIN pg_namespace AS tnsp ON trel.relnamespace = tnsp.oid 
JOIN pg_class AS irel ON irel.oid = i.indexrelid 
CROSS JOIN LATERAL unnest (i.indkey) WITH ORDINALITY AS c (colnum, ordinality) 
JOIN pg_attribute AS a ON trel.oid = a.attrelid AND a.attnum = c.colnum 
GROUP BY tnsp.nspname, trel.relname, irel.relname