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A comment on Postgres 9.4 feature highlight: Indexing JSON data with jsonb data type. Parent comment

Re:Postgres 9.4 feature highlight: Indexing JSON data with j... by moe on Monday November 17, 2014 @06:42AM (#8617759)
with hot master failover and command forwarding [...] like I get with MongoDB.

Failover is documented to not work very well in MongoDB (data loss): http://aphyr.com/posts/284-call-me-maybe-mongodb

On the postgres side RepMgr makes dealing with replication quite easy: https://github.com/2ndQuadrant/repmgr

See also this recent thread on the PostgreSQL mailing list: http://postgresql.nabble.com/Fully-automatic-streaming-repli...

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Re:Postgres 9.4 feature highlight: Indexing JSON data with j... by Xylakant on Monday November 17, 2014 @11:08AM (#8618773)
I'd be careful quoting the aphyr post in that context. PG also had some failures, even in the non-replicated setup: http://aphyr.com/posts/282-call-me-maybe-postgres

Failures are just a property of distributed systems, some fail in ways that are better for you, some fail in ways that are worse, but sooner or later they all fail. It's a tradeoff which one you choose.

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Re:Postgres 9.4 feature highlight: Indexing JSON data with j... by moe on Monday November 17, 2014 @11:57AM (#8619051)
PG also had some failures

MongoDB loses acknowledged writes in its supposed "highest consistency" mode.

PostgreSQL does not.

That's a pretty fundamental difference, don't you think?

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Re:Postgres 9.4 feature highlight: Indexing JSON data with j... by Xylakant on Monday November 17, 2014 @01:06PM (#8619456)
MongoDB was tested in a replicated setup, PG not, that's a pretty fundamental difference. Loosing acked writes in a master-slave replication with failover would be expected with a sufficiently large replication lag even for PG.

MongoDB is about the last database I'd pick for any given scenario, but I acknowledge that there are people that have a usecase where it might be a good fit because the tradeoffs work out for them.

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Re:Postgres 9.4 feature highlight: Indexing JSON data with j... by moe on Tuesday November 18, 2014 @06:41AM (#8623467)
Loosing acked writes in a master-slave replication with failover would be expected with a sufficiently large replication lag even for PG.

Bullshit.

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