Hi justin I raised question based on the reference link https://opensource-db.com/unlocking-initial-sync-for-logical-replication-in-aws-rds-for-postgresql/ .. you can also go through it to see the steps This worked on postgres 10version but on postgres 14 I can go through the info you provided to implement the same
Thanks for your valuable information Regards, Durga Mahesh On Sat, 28 Sept, 2024, 23:10 Justin, <zzzzz.g...@gmail.com> wrote: > > > 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 > >
