如何在 PostgreSQL 中檢索索引列？

擷取 PostgreSQL 中的索引列

要取得 PostgreSQL 中索引的資料列，您可以使用下列查詢：

SELECT
    t.relname AS table_name,
    i.relname AS index_name,
    a.attname AS column_name
FROM
    pg_class t,
    pg_class i,
    pg_index ix,
    pg_attribute a
WHERE
    t.oid = ix.indrelid
    AND i.oid = ix.indexrelid
    AND a.attrelid = t.oid
    AND a.attnum = ANY(ix.indkey)
    AND t.relkind = 'r';

要按索引進一步聚合結果，請使用此查詢：

SELECT
    t.relname AS table_name,
    i.relname AS index_name,
    array_to_string(array_agg(a.attname), ', ') AS column_names
FROM
    pg_class t,
    pg_class i,
    pg_index ix,
    pg_attribute a
WHERE
    t.oid = ix.indrelid
    AND i.oid = ix.indexrelid
    AND a.attrelid = t.oid
    AND a.attnum = ANY(ix.indkey)
    AND t.relkind = 'r'
GROUP BY
    t.relname,
    i.relname;

PostgreSQL 元資訊擷取的其他資源：

• [pg_index] (https://www.postgresql.org/docs /current/static/view-pg-index.html)
• ["從中提取META 資訊PostgreSQL"](https://www.depesz.com/2007/08/12/extracting-meta-information -from-postgresql/)

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