Перечислите все имена индексов, имена столбцов и имена таблиц базы данных PostgreSQL

Question

Что такое запрос для получения списка всех имен индексов, имени его столбца и имени таблицы базы данных postgresql?

Я попытался получить список всех индексов в БД, используя этот запросно как получить список индексов, имена столбцов и имена таблиц?

 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

При этом будут выведены все индексы с подробностями (извлечено из определений моего представления):

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;

При желании можно добавить дополнительное объединение в конец, чтобы обрезать пространства имен:

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

Более дружественная к человеку версия решения @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

Запрос для перечисления всех индексов базы данных

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

Вот версия, которая упрощает вещи по сравнению с другими ответами на

• , избегая вложенных выборок
• , избегая встроенных функций (возможно, трудно запомнить)
• , используяФункции LATERAL и UNNEST(...) WITH ORDINALITY, доступные в более поздних версиях PostgreSQL (9.4 +)

SELECT
  tnsp.nspname AS schema_name,
  trel.relname AS table_name,
  irel.relname AS index_name,
  array_agg (
     a.attname 
  || ' ' || CASE o.option & 1 WHEN 1 THEN 'DESC' ELSE 'ASC' END
  || ' ' || CASE o.option & 2 WHEN 2 THEN 'NULLS FIRST' ELSE 'NULLS LAST' END
    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)
LEFT JOIN LATERAL unnest (i.indoption) WITH ORDINALITY AS o (option, ordinality)
  ON c.ordinality = o.ordinality
JOIN pg_attribute AS a ON trel.oid = a.attrelid AND a.attnum = c.colnum
GROUP BY tnsp.nspname, trel.relname, irel.relname

Answer 5

Если вас также интересует размер индекса , вы можете использовать этот запрос из 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;