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Traditionally MySQL has been ahead of Postgres in terms of replication, but Postgres has made great strides in that department recently. Having said that, Postg

by spudlyo 14y ago

Traditionally MySQL has been ahead of Postgres in terms of replication, but Postgres has made great strides in that department recently. Having said that, Postgres still doesn't support master-master or ring topologies, replication filtering, and is binary only (which is probably a good thing).

fdr 14y ago
Naah, I wouldn't go so far to say it's a good thing that it's missing, but it's hellaciously hard to implement well. I think the sentiment is rendered well in this mail, which took place after extensive review and hacking. In it, Robert Haas (a committer) writes to Andres Freund (the principal author, I believe): Before getting bogged down in technical commentary, let me say this very clearly: I am enormously grateful for your work on this project. Logical replication based on WAL decoding is a feature of enormous value that PostgreSQL has needed for a long time, and your work has made that look like an achievable goal. Furthermore, it seems to me that you have pursued the community process with all the vigor and sincerity for which anyone could ask. Serious design concerns were raised early in the process and you made radical changes to the design which I believe have improved it tremendously, and you've continued to display an outstanding attitude at every phase of this process about which I can't say enough good things. There is no question in my mind that this work is going to be the beginning of a process that revolutionizes the way people think about replication and PostgreSQL, and you deserve our sincere thanks for that. Now, the bad news is, I don't think it's very reasonable to try to commit this to 9.3. I think it is just too much stuff too late in the cycle. I've reviewed some of the patches from time to time but there is a lot more stuff and it's big and complicated and it's not really clear that we have the interface quite right yet, even though I think it's also clear that we are a lot of closer than we were. I don't want to be fixing that during beta, much less after release. http://www.postgresql.org/message-id/CA+TgmoYhkMpkB8JZYhVei--h-onT-kT-Ko8bHvrrBUsewi_u-Q@mail.gmail.com http://www.postgresql.org/message-id/CA+TgmoYhkMpkB8JZYhVei-... The implications for PostgreSQL version upgrade alone are enormous. MySQL has been ahead here, even though some if it was at the cost of some sanity, and by lack of sanity I mean "statement based replication". The first semi-sane logical replication was the 2008 release that included row-based-replication.

by spudlyo 14y ago

fdr 14y ago

Naah, I wouldn't go so far to say it's a good thing that it's missing, but it's hellaciously hard to implement well. I think the sentiment is rendered well in this mail, which took place after extensive review and hacking. In it, Robert Haas (a committer) writes to Andres Freund (the principal author, I believe): Before getting bogged down in technical commentary, let me say this very clearly: I am enormously grateful for your work on this project. Logical replication based on WAL decoding is a feature of enormous value that PostgreSQL has needed for a long time, and your work has made that look like an achievable goal. Furthermore, it seems to me that you have pursued the community process with all the vigor and sincerity for which anyone could ask. Serious design concerns were raised early in the process and you made radical changes to the design which I believe have improved it tremendously, and you've continued to display an outstanding attitude at every phase of this process about which I can't say enough good things. There is no question in my mind that this work is going to be the beginning of a process that revolutionizes the way people think about replication and PostgreSQL, and you deserve our sincere thanks for that. Now, the bad news is, I don't think it's very reasonable to try to commit this to 9.3. I think it is just too much stuff too late in the cycle. I've reviewed some of the patches from time to time but there is a lot more stuff and it's big and complicated and it's not really clear that we have the interface quite right yet, even though I think it's also clear that we are a lot of closer than we were. I don't want to be fixing that during beta, much less after release. http://www.postgresql.org/message-id/CA+TgmoYhkMpkB8JZYhVei--h-onT-kT-Ko8bHvrrBUsewi_u-Q@mail.gmail.com http://www.postgresql.org/message-id/CA+TgmoYhkMpkB8JZYhVei-... The implications for PostgreSQL version upgrade alone are enormous. MySQL has been ahead here, even though some if it was at the cost of some sanity, and by lack of sanity I mean "statement based replication". The first semi-sane logical replication was the 2008 release that included row-based-replication.