title: Vacuum analyze after huge deleting of rows not freeing space in postgres
body: <p>I delete a huge amount of rows in our postgres database and ran a vacuum analyze later on.</p>
  
  <p>I noticed the disk usage did not moved much in AWS RDS console.</p>
  
  <p>Tried running the query, based on that the table size did not move much as well.</p>
  
  <pre><code>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 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
            FROM pg_class c
            LEFT JOIN pg_namespace n ON n.oid = c.relnamespace
            WHERE relkind = 'r'
    ) a
  ) a order by total_bytes desc;
  </code></pre>
  
  <p>Is this normal? Or disk space are not being reclaimed at all?</p>