@@ -3563,6 +3563,14 @@ pg_probackup catchup -b <replaceable>catchup_mode</replaceable> --source-pgdata=
35633563 of threads with the <option >--threads</option > option:
35643564 <programlisting >
35653565pg_probackup catchup -b <replaceable >catchup_mode</replaceable > --source-pgdata=<replaceable >path_to_pgdata_on_remote_server</replaceable > --destination-pgdata=<replaceable >path_to_local_dir</replaceable > --stream --threads=<replaceable >num_threads</replaceable >
3566+ </programlisting >
3567+ </para >
3568+ <para >
3569+ Before cloning/synchronising a <productname >PostgreSQL</productname > instance, you can run the
3570+ <command >catchup</command > command with the <option >--dry-run</option > flag
3571+ to estimate the size of data files to be transferred, but make no changes on disk:
3572+ <programlisting >
3573+ pg_probackup catchup -b <replaceable >catchup_mode</replaceable > --source-pgdata=<replaceable >path_to_pgdata_on_remote_server</replaceable > --destination-pgdata=<replaceable >path_to_local_dir</replaceable > --stream --dry-run
35663574</programlisting >
35673575 </para >
35683576 <para >
@@ -3576,7 +3584,7 @@ pg_probackup catchup --source-pgdata=/master-pgdata --destination-pgdata=/replic
35763584 <para >
35773585 Another example shows how you can add a new remote standby server with the <productname >PostgreSQL</productname > data directory <filename >/replica-pgdata</filename > by running the <command >catchup</command > command in the <literal >FULL</literal > mode
35783586 on four parallel threads:
3579- <programlisting >
3587+ <programlisting >
35803588pg_probackup catchup --source-pgdata=/master-pgdata --destination-pgdata=/replica-pgdata -p 5432 -d postgres -U remote-postgres-user --stream --backup-mode=FULL --remote-host=remote-hostname --remote-user=remote-unix-username -j 4
35813589</programlisting >
35823590 </para >
@@ -4482,7 +4490,7 @@ pg_probackup archive-get -B <replaceable>backup_dir</replaceable> --instance <re
44824490pg_probackup catchup -b <replaceable >catchup_mode</replaceable >
44834491--source-pgdata=<replaceable >path_to_pgdata_on_remote_server</replaceable >
44844492--destination-pgdata=<replaceable >path_to_local_dir</replaceable >
4485- [--help] [-j | --threads=<replaceable >num_threads</replaceable >] [--stream]
4493+ [--help] [-j | --threads=<replaceable >num_threads</replaceable >] [--stream] [--dry-run]
44864494[--temp-slot] [-P | --perm-slot] [-S | --slot=<replaceable >slot_name</replaceable >]
44874495[--exclude-path=<replaceable >PATHNAME</replaceable >]
44884496[-T <replaceable >OLDDIR</replaceable >=<replaceable >NEWDIR</replaceable >]
@@ -4571,6 +4579,19 @@ pg_probackup catchup -b <replaceable>catchup_mode</replaceable>
45714579 </listitem >
45724580 </varlistentry >
45734581
4582+ <varlistentry >
4583+ <term ><option >--dry-run</option ></term >
4584+ <listitem >
4585+ <para >
4586+ Displays the total size of the files to be transferred by <command >catchup</command >.
4587+ This flag initiates a trial run of <command >catchup</command >, which does
4588+ not actually create, delete or move files on disk. WAL streaming is skipped with <option >--dry-run</option >.
4589+ This flag also allows you to check that
4590+ all the options are correct and cloning/synchronising is ready to run.
4591+ </para >
4592+ </listitem >
4593+ </varlistentry >
4594+
45744595 <varlistentry >
45754596<term ><option >-x</option >=<replaceable >path_prefix</replaceable ></term >
45764597<term ><option >--exclude-path</option >=<replaceable >path_prefix</replaceable ></term >
@@ -4591,17 +4612,6 @@ pg_probackup catchup -b <replaceable>catchup_mode</replaceable>
45914612 </listitem >
45924613 </varlistentry >
45934614
4594- <varlistentry >
4595- <term ><option >--stream</option ></term >
4596- <listitem >
4597- <para >
4598- Copies the instance in <link linkend =" pbk-stream-mode" >STREAM</link > WAL delivery mode,
4599- including all the necessary WAL files by streaming them from
4600- the instance server via replication protocol.
4601- </para >
4602- </listitem >
4603- </varlistentry >
4604-
46054615 <varlistentry >
46064616<term ><option >--temp-slot</option ></term >
46074617 <listitem >