-- Creates a relcache entry for each table and index in the connection's backend process
SET max_parallel_workers_per_gather = 0;
SELECT COUNT(pg_relation_size(oid)) FROM pg_class WHERE relkind IN ('i', 'r');

SELECT name,
       "type",
       count(*),
       sum(total_bytes) total_bytes,
       sum(total_nblocks) total_nblocks,
       sum(free_bytes) free_bytes,
       sum(free_chunks) free_chunks,
       sum(used_bytes) used_bytes,
       sum(used_bytes) / sum(total_nblocks) AS hinky_chunk_size
FROM pg_backend_memory_contexts
WHERE path @> (SELECT path FROM pg_backend_memory_contexts WHERE name = 'CacheMemoryContext')
GROUP BY GROUPING SETS ((name, "type"), ());


master

        name        |   type   | count  | total_bytes | total_nblocks | free_bytes | free_chunks | used_bytes |   hinky_chunk_size    
--------------------+----------+--------+-------------+---------------+------------+-------------+------------+-----------------------
 CacheMemoryContext | AllocSet |      1 |   624091472 |          1654 |    6070048 |         106 |  618021424 |   373652.614268440145
 index info         | AllocSet | 178355 |   291233360 |        231489 |   95564464 |      156244 |  195668896 |  845.2621766045038857
 relation rules     | AllocSet |      1 |        8192 |             4 |       3840 |           1 |       4352 | 1088.0000000000000000
                    |          | 178357 |   915333024 |        233147 |  101638352 |      156351 |  813694672 | 3490.0499341617091363

patched

         name         |   type   | count  | total_bytes | total_nblocks | free_bytes | free_chunks | used_bytes |   hinky_chunk_size    
----------------------+----------+--------+-------------+---------------+------------+-------------+------------+-----------------------
 CacheMemoryContext   | AllocSet |      1 |   624091472 |          1654 |    5922416 |         104 |  618169056 |   373741.871825876663
 index info           | Proxy    | 178355 |    45610512 |        535092 |          0 |           0 |   45610512 |   85.2386355991119284
 index shape          | Proxy    |    225 |      305160 |           225 |          0 |           0 |     305160 | 1356.2666666666666667
 relation rules       | AllocSet |      1 |        8192 |             4 |       3840 |           1 |       4352 | 1088.0000000000000000
 Relation shape cache | AllocSet |      1 |       32768 |             3 |      15928 |           0 |      16840 | 5613.3333333333333333
 Relation shape hash  | AllocSet |      1 |       65536 |             4 |      37320 |          15 |      28216 | 7054.0000000000000000
                      |          | 178584 |   670113640 |        536982 |    5979504 |         120 |  664134136 | 1236.7903132693460861