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.graf@xxxxxxxxx> wrote:
--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 | pgoutputRegards,
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
