On Sat, Sep 28, 2024 at 1:04 AM Durgamahesh Manne <maheshpostgr...@gmail.com> wrote:
> Hi Team > > Can anyone respond to my question from respected team members ? > > Durga Mahesh > > On Thu, Sep 26, 2024 at 2:23 AM Durgamahesh Manne < > maheshpostgr...@gmail.com> wrote: > >> Hi Team >> >> --snapshot=snapshotname >> (Use the specified synchronized snapshot when making a dump of the >> database >> >> This option is useful when needing to synchronize the dump with a logical >> replication slot) as per the pgdg >> >> How do we synchronize the dump with a logical replication slot with >> --snapshot? >> >> I am using the postgresql 14 version which supports only >> pg_create_logical_replication_slot. How to generate a internal snapshot >> with it ? >> >> Below CREATE_REPLICAION_SLOT not supported by postgresql 14 >> >> example osdb_lsr=# CREATE_REPLICATION_SLOT lsr_sync_01 LOGICAL pgoutput; >> slot_name | consistent_point | snapshot_name | output_plugin >> -------------+------------------+---------------------+--------------- >> lsr_sync_01 | 0/C000110 | 00000003-00000002-1 | pgoutput >> >> Regards, >> >> Durga Mahesh >> >> >> >> On Fri, 20 Sept, 2024, 01:27 Durgamahesh Manne, < >> maheshpostgr...@gmail.com> wrote: >> >>> Hi Team >>> >>> --snapshot=*snapshotname* >>> >>> (Use the specified synchronized snapshot when making a dump of the >>> database >>> >>> This option is useful when needing to synchronize the dump with a >>> logical replication slot) as per the pgdg >>> >>> How do we synchronize the dump with a logical replication slot >>> with --snapshot? >>> >>> I am using the postgresql 14 version which supports only >>> pg_create_logical_replication_slot. How to generate a snapshot with it ? >>> >>> Below CREATE_REPLICAION_SLOT not supported by postgresql 14 >>> >>> example osdb_lsr=# CREATE_REPLICATION_SLOT lsr_sync_01 LOGICAL pgoutput; >>> slot_name | consistent_point | snapshot_name | output_plugin >>> -------------+------------------+---------------------+--------------- >>> lsr_sync_01 | 0/C000110 | 00000003-00000002-1 | pgoutput >>> >>> Regards, >>> >>> Durga Mahesh >>> >> Hi Durgamahesh, I am not sure what you are after with matching pg_dump and replication slot together unless you are trying to get a dump to handle the initial data sync. There is not a benefit to doing that as the WAL is going to build up on the publisher... You have to create a snapshot using the export function https://www.postgresql.org/docs/current/sql-set-transaction.html https://www.postgresql.org/docs/17/functions-admin.html#FUNCTIONS-SNAPSHOT-SYNCHRONIZATION Then you can create the logical replication slot with using that slotname option https://www.postgresql.org/docs/17/sql-createsubscription.html#SQL-CREATESUBSCRIPTION-PARAMS-WITH-SLOT-NAME and no sync option. Then you tell pg_dump to use that snapshot name snapshot with this option --snapshot=snapshotname https://www.postgresql.org/docs/current/app-pgdump.html Once pg_restore is done on the destination , you can create a subscription using that slotname option probably and specify copy_data = false. Keep in mind the WAL will build up during this process, not sure what the benefit would be just allowing logical replication to do the initial sync. Thanks Justin
