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base repository: postgresql-cfbot/postgresql
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  • 4 commits
  • 24 files changed
  • 2 contributors

Commits on Dec 23, 2025

  1. Add batch table AM API and heapam implementation 

    Introduce new table AM callbacks to fetch multiple tuples per call.
This reduces per-tuple call overhead by letting executor nodes work
in batches.

Define a HeapBatch structure and supporting code in tableam.h.
Batches are limited to tuples from a single page and at most
EXEC_BATCH_ROWS (currently 64) entries.

Provide initial heapam support with heapgettup_pagemode_batch().
No executor node is switched over yet; a later commit will adapt
SeqScan to use this API. Other nodes may adopt it in the future.

Also add pgstat_count_heap_getnext_batch() to record batched fetches
in pgstat.

Reviewed-by: Daniil Davydov <3danissimo@gmail.com>
Discussion: https://postgr.es/m/CA+HiwqFfAY_ZFqN8wcAEMw71T9hM_kA8UtyHaZZEZtuT3UyogA@mail.gmail.com
    @amitlan
    amitlan authored and Commitfest Bot committed Dec 23, 2025
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  2. SeqScan: add batch-driven variants returning slots 

    Teach SeqScan to drive the table AM via new the batch API added in
the previous commit, while still returning one TupleTableSlot at a
time to callers. This reduces per tuple AM crossings without
changing the node interface seen by parents.

Add TupleBatch and supporting code in execBatch.c/h to hold executor
side batching state. PlanState gains ps_Batch to carry the active
TupleBatch when a node supports batching.

Wire up runtime selection in ExecInitSeqScan using
ScanCanUseBatching(). When executor_batching is enabled, EPQ is
inactive, the scan is not backward, and the relation supports
batching, ps.ExecProcNode is set to a batch-driven variant. Otherwise
the non-batch path is used.

Plan shape and EXPLAIN output remain unchanged; only the internal
tuple flow differs when batching is enabled and allowed.

Add executor_batch_rows GUC to specify the maximum number of rows
that can be added into a batch.

Notes / current limits:

- With the current heapam, batches are composed from a single page, so
  the batch may not always be full. Future work may let SeqScan and/or
  AMs top up batches across pages when safe to do so.

Reviewed-by: Daniil Davydov <3danissimo@gmail.com>
Discussion: https://postgr.es/m/CA+HiwqFfAY_ZFqN8wcAEMw71T9hM_kA8UtyHaZZEZtuT3UyogA@mail.gmail.com
    @amitlan
    amitlan authored and Commitfest Bot committed Dec 23, 2025
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  3. Add EXPLAIN (BATCHES) option for tuple batching statistics 

    Add a BATCHES option to EXPLAIN that reports per-node batch statistics
when a node uses batch mode execution.

For nodes that support batching (currently SeqScan), this shows the
number of batches fetched along with average, minimum, and maximum
rows per batch. Output is supported in both text and non-text formats.

Add regression tests covering text output, JSON format, filtered scans,
LIMIT, and disabled batching.

Discussion: https://postgr.es/m/CA+HiwqFfAY_ZFqN8wcAEMw71T9hM_kA8UtyHaZZEZtuT3UyogA@mail.gmail.com
    @amitlan
    amitlan authored and Commitfest Bot committed Dec 23, 2025
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  4. [CF 6176] v4 - Batching in executor, part 1: add batch variant of tab… 

    …le AM scan API

This branch was automatically generated by a robot using patches from an
email thread registered at:

https://commitfest.postgresql.org/patch/6176

The branch will be overwritten each time a new patch version is posted to
the thread, and also periodically to check for bitrot caused by changes
on the master branch.

Patch(es): https://www.postgresql.org/message-id/CA+HiwqEZja5rJ78p3FBDZNvynWsHwanxyt6h0YaK_r84NemXng@mail.gmail.com
Author(s): Amit Langote
    Commitfest Bot committed Dec 23, 2025
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