Re: Revive num_dead_tuples column of pg_stat_progress_vacuum

On 2024-Jun-03, Masahiko Sawada wrote:

> Commit 667e65aac3 changed num_dead_tuples and max_dead_tuples columns
> to dead_tuple_bytes and max_dead_tuple_bytes columns, respectively.
> But at PGConf.dev, I got feedback from multiple people that
> num_dead_tuples information still can provide meaning insights for
> users to understand the vacuum progress. One use case is to compare
> num_dead_tuples to pg_stat_all_tables.n_dead_tup column.

+1.

> @@ -2887,7 +2887,9 @@ dead_items_add(LVRelState *vacrel, BlockNumber blkno, OffsetNumber *offsets,
> TidStoreSetBlockOffsets(dead_items, blkno, offsets, num_offsets);
> vacrel->dead_items_info->num_items += num_offsets;
>
> - /* update the memory usage report */
> + /* update the progress information */
> + pgstat_progress_update_param(PROGRESS_VACUUM_NUM_DEAD_TUPLES,
> + vacrel->dead_items_info->num_items);
> pgstat_progress_update_param(PROGRESS_VACUUM_DEAD_TUPLE_BYTES,
> TidStoreMemoryUsage(dead_items));
> }

You could use pgstat_progress_update_multi_param here.

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