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commit    bd2aebd7a7fe38b8ad832a10d5bfd1d841f048d8
Author:   Masahiko Sawada <msawada@postgresql.org>
Date:     Wed Sep 23 21:57:48 2026 +0000

    doc: Clarify phase descriptions of pg_stat_progress_repack.
    
    The "initializing" phase was described as expected to be very brief,
    but for REPACK (CONCURRENTLY), it also covers enabling and
    initializing logical decoding, either of which can take a long
    time. Also, the "catch-up" phase includes waiting for the ACCESS
    EXCLUSIVE lock needed to swap the files, which was not mentioned.
    
    Adding separate progress phases for these steps is left for v20; for
    v19 we only clarify the description.
    
    Author: Sami Imseih <samimseih.pg@gmail.com>
    Reviewed-by: Masahiko Sawada <sawada.mshk@gmail.com>
    Reviewed-by: Manuel Reyes Bravo <manuelreyesbravo@gmail.com>
    Discussion: https://postgr.es/m/CAN12%2BYJOeOyPYB5JS28VE_%2Brzg%3DRbzQXfj58TGfMYwv-TX9mJA%40mail.gmail.com
    Backpatch-through: 19


 doc/src/sgml/monitoring.sgml | 19 +++++++++++++++++--
 1 file changed, 17 insertions(+), 2 deletions(-)

diff --git a/doc/src/sgml/monitoring.sgml b/doc/src/sgml/monitoring.sgml
index 62dadf3e86c..0d038de1a23 100644
--- a/doc/src/sgml/monitoring.sgml
+++ b/doc/src/sgml/monitoring.sgml
@@ -7601,7 +7601,19 @@ FROM pg_stat_get_backend_idset() AS backendid;
      <entry><literal>initializing</literal></entry>
      <entry>
        The command is preparing to begin scanning the heap.  This phase is
-       expected to be very brief.
+       expected to be very brief, except for
+       <command>REPACK CONCURRENTLY</command>, where it also covers enabling
+       logical decoding and then initializing it.  Enabling has nothing to do
+       if <xref linkend="guc-effective-wal-level"/> is already
+       <literal>logical</literal>; otherwise it waits for all processes to
+       acknowledge that they started writing the additional WAL information
+       that logical decoding requires.  Initializing then waits for the
+       transactions that have been assigned a transaction ID to end, including
+       ones that started while this wait was in progress, so this phase can
+       last longer than the longest transaction running when the command
+       started.  This includes any other
+       <command>REPACK CONCURRENTLY</command>, which holds a transaction ID
+       until it finishes.
      </entry>
     </row>
     <row>
@@ -7633,7 +7645,10 @@ FROM pg_stat_get_backend_idset() AS backendid;
      <entry>
        <command>REPACK CONCURRENTLY</command> is currently processing the DML
        commands that other transactions executed during any of the preceding
-       phases.
+       phases.  This phase also covers waiting for the <literal>ACCESS
+       EXCLUSIVE</literal> lock needed to swap the files, so a command blocked
+       by a conflicting lock stays in this phase.
+       This phase is skipped when not in concurrent mode.
      </entry>
     </row>
     <row>