20240816_PS_COMMIT_MESSAGE_SEQ_0004

Below is my suggestion for some small changes to the patch 0004 commit meesage

//////////
BEFORE

This commit introduces sequence synchronization:
1) During subscription creation:
   - The subscriber retrieves sequences associated with publications.
   - Sequences  are added in 'init' state to pg_subscription_rel table.
   - A new sequence synchronization worker handles synchronization in
     batches of 100 sequences:
     a) Retrieves sequence values using pg_sequence_state from the publisher.
     b) Sets sequence values accordingly.
     c) Updates sequence state to 'READY'.
     d) Commits batches of 100 synchronized sequences.

2) Refreshing sequences:
   - Refreshing sequences occurs with
        ALTER SUBSCRIPTION ... REFRESH PUBLICATION (no syntax change).
   - Stale sequences are removed from pg_subscription_rel.
   - Newly added sequences in the publisher are added in 'init'
     state to pg_subscription_rel.
   - Initiates sequence synchronization for all sequences by sequence
     sync worker as listed in subscription creation process.
   - Sequence synchronization occurs for newly added sequences only.

3) Introduce new command for refreshing all sequences:
   - ALTER SUBSCRIPTION ... REFRESH PUBLICATION SEQUENCES.
   - Removes stale sequences and adds newly added sequences from
     the publisher to pg_subscription_rel.
   - Resets all sequences in pg_subscription_rel to 'init' state.
   - Initiates sequence synchronization for all sequences by sequence
     sync worker as listed in subscription creation process.
	 
////////// 
AFTER

This patch introduces sequence synchronization:

Sequences have 2 states:
	- INIT (needs synchronizing)
	- READY (is already synchronized)
	
A new sequencesync worker is launched as needed to synchronize sequences.
It does the following:
    a) Retrieves remote values of sequences with pg_sequence_state() INIT.
    b) Sets the local sequence values accordingly.
    c) Updates the local sequence state to READY.
    d) Repeat until all done; Commits synchronized sequences in batches of 100 

~~

Sequence synchronization occurs in 3 places:

1) CREATE SUBSCRIPTION
    - (PG17 command syntax is unchanged)
    - The subscriber retrieves sequences associated with publications.
    - Publisher sequences are added to pg_subscription_rel with INIT state.
    - Initiates the sequencesync worker (see above) to synchronize all
      sequences. 
	 
2) ALTER SUBSCRIPTION ... REFRESH PUBLICATION
    - (PG17 command syntax is unchanged)
    - Dropped publisher sequences are removed from pg_subscription_rel.
    - New publisher sequences are added to pg_subscription_rel with INIT state.
	- Initiates the sequencesync worker (see above) to synchronize only
      newly added sequences.

3) ALTER SUBSCRIPTION ... REFRESH PUBLICATION SEQUENCES
	- The patch introduces this new command to refresh all sequences
    - Dropped publisher sequences are removed from pg_subscription_rel.
    - New publisher sequences are added to pg_subscription_rel
    - All sequences in pg_subscription_rel are reset to INIT state.
	- Initiates the sequencesync worker (see above) to synchronize all
      sequences.

[END]