Horton

Use bump context for TID bitmaps stored by vacuum

John Naylor <john.naylor@postgresql.org>

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Commit: 8a1b31e6e59631807a08a4e9465134c343bbdf5e
Author: John Naylor <john.naylor@postgresql.org>
Date: 2024-04-08T07:39:49Z
Releases: 17.0 
Use bump context for TID bitmaps stored by vacuum

Vacuum does not pfree individual entries, and only frees the entire
storage space when finished with it. This allows using a bump context,
eliminating the chunk header in each leaf allocation. Most leaf
allocations will be 16 to 32 bytes, so that's a significant savings.
TidStoreCreateLocal gets a boolean parameter to indicate that the
created store is insert-only.

This requires a separate tree context for iteration, since we free
the iteration state after iteration completes.

Discussion: https://postgr.es/m/CANWCAZac%3DpBePg3rhX8nXkUuaLoiAJJLtmnCfZsPEAS4EtJ%3Dkg%40mail.gmail.com
Discussion: https://postgr.es/m/CANWCAZZQFfxvzO8yZHFWtQV+Z2gAMv1ku16Vu7KWmb5kZQyd1w@mail.gmail.com

Files

PathChange+/−
src/backend/access/common/tidstore.c modified +13 −2
src/backend/access/heap/vacuumlazy.c modified +2 −2
src/include/access/tidstore.h modified +1 −1
src/include/lib/radixtree.h modified +10 −1
src/test/modules/test_tidstore/test_tidstore.c modified +2 −1

Discussion