[HN Gopher] The Wonders of Postgres Logical Decoding Messages
       ___________________________________________________________________
        
       The Wonders of Postgres Logical Decoding Messages
        
       Author : rbanffy
       Score  : 63 points
       Date   : 2023-03-31 20:21 UTC (1 days ago)
        
 (HTM) web link (www.infoq.com)
 (TXT) w3m dump (www.infoq.com)
        
       | cryptonector wrote:
       | NOTIFY also can be used this way.
        
         | klysm wrote:
         | Notify is really hard to use correctly, and I think logical
         | replication works better in most cases
        
         | semiquaver wrote:
         | Correct me if I'm wrong but even though NOTIFY is
         | transactional, it isn't persisted to WAL or anywhere else ---
         | so any clients that were not LISTENing at the time NOTIFY was
         | called cannot receive it retroactively. WAL is, well, a _log_
         | which has nicer properties for many applications that allow
         | clients to "fall behind" or recover from transient network
         | disconnects without losing data.
        
       | aynyc wrote:
       | Does it support some form of checkpointing without Flink? I would
       | like to run debezium without Flink.
        
         | jakehilborn wrote:
         | Yes. Postgres stores the checkpoint on the source database
         | replication slot. You can configure Debezium Engine to send
         | checkpoints to the file /dev/null to disable the default
         | external system checkpoint behavior.
        
           | aynyc wrote:
           | Any documentation on this? We ran an assortment of outbox
           | pattern for data distribution, I don't want to manage that in
           | data producers anymore.
        
       | simonw wrote:
       | I remember hearing years ago that Facebook used a trick like this
       | for cache invalidation: they would write custom "invalidate cache
       | X" messages (maybe even as SQL comments?) into their MySQL
       | replication streams that fanned out to multiple data centers,
       | such that a data center would know to clear a cached record out
       | of its local memcached cluster when the relevant MySQL rows were
       | updated.
        
       | paulddraper wrote:
       | That's so cool.
        
       ___________________________________________________________________
       (page generated 2023-04-01 23:01 UTC)