I want all tables to be replicated by bucardo (at least for a given database), but it looks like I have to add them all manually:
bucardo_ctl add all tables
Can I have it so that every table in a database is replicated, or added to bucardo automatically?
If not, is there another replication strategy in Postgresql that might be better fit for me? I'm hoping to have all nodes available for reads/writes, to avoid administering any routing process to route the writes to the master. If the routing of writes can be done natively in Postgresql, then that could be a solution as well.
Use below command for add all
bucardo add all tables
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I use postgresql. I have many databases in a server. There is one database which I use the most say 'main'. This 'main' has many tables inside it. And also other databases have many tables inside them.
What I want to do is, whenever a new row is inserted into 'main.users' table I wish to insert the same data into 'users' table of other databases. How shall I do it in postgresql? Similarly I wish to do the same for all actions like UPDATE, DELETE etc.,
I had gone through the "logical replication" concept as suggested by you. In my case I know the source db name up front and I will come to know the target db name as part of the query. So it is going to be dynamic.
How to achieve this? is there any db concept available in postgresql? Or I welcome all other possible ways as well. Please share me some idea on this.
If this is all on the same Postgres instance (aka "cluster"), then I would recommend to use a foreign table to access the tables from the "main" database in the other databases.
Those foreign tables look like "local" tables inside each database, but access the original data in the source database directly, so there is no need to synchronize anything.
Upgrade to a recent PostgreSQL release and use logical replication.
Add a trigger on the table in the master database that uses dblink to access and write the other databases.
Be sure to consider what should be done if the row alreasdy exists remotely, or if the rome server is unreachable.
Also not that updates propogated usign dblink are not rolled back if the inboking transaction is rolled back
I have two databases with tables that I want to sync. I don't want to sync any other table. I'm using Postgres-BDR to do that.
Those tables are part of replication set common. There are some circumstances where other tables share a name across nodes (but are NOT in common), and a node will call DROP TABLE and then CREATE TABLE. Even though those tables aren't part of the common replication set, these commands are still replicated to the other nodes, causing the other node to lose all of its data in its table and then create an empty table.
How can I stop this? I only want commands that affect common to be replicated to the other nodes.
Nevermind, I found it. It's available with bdr.skip_ddl_replication.
I just put bdr.skip_ddl_replication = on in postgresql.conf, restarted the server, and BOOM! Works like a charm.
EDIT
It would be prudent of me to point out that the documentation warns that this option could break database replication if used improperly. But since I'll be VERY tightly controlling the table schema, it shouldn't cause any problems.
I have 5 users which uses 5 different servers(using openerp), each one uses the same database copy. Whenever the user enters data to his database, then it should sync to the 6th server's database an then sync the data in the 6th database to all other 4 users databases. So any data entry in any database should sync to the other databases running in different servers. Is that possible? how can I achieve it?
Edit:
I found Bucardo, but it need primary key for every table. But in openerp, there are many2many relation tables which doesn't have a primary key.
This is called master-master or multi-master replication:
http://en.wikipedia.org/wiki/Multi-master_replication#PostgreSQL
http://wiki.postgresql.org/wiki/Replication,_Clustering,_and_Connection_Pooling
You can also check out SymmetricDS or Daffodil which let you sync over HTTP.
A pure PostgreSQL installation supports currently only single master replication.
However you may achieve multi-master replication by installing additional tools http://wiki.postgresql.org/wiki/Clustering.
You should also check out Pg documentation on this topic Chapter 25. High Availability, Load Balancing, and Replication
What would be the best way to replicate individual DB tables from a Master postgresql server to a slave machine? It can be done with cron+rsync, or with whatever postgresql might have build in, or some sort of OSS tool, but so far the postgres docs don't seem to cover how to do table replication. I'm not able to do a full DB replication because some tables have license->IP stuff connected to it, and I can't replicate those on the slave machine. I don't need instant replication, hourly would be acceptable as well.
If I need to just rsync, can someone help identify what files within the /var/lib/pgsql directory would need to be synced, or how I would know what tables they are.
Starting with Postgres 10, logical replication is built into Postgres! This is often a better solution than external solutions. The Postgres docs are great and easy to follow. It's very easy. See the quick setup docs, which in essense boils down to running this:
-- On publisher DB
CREATE PUBLICATION mypub FOR TABLE users, departments;
-- On subscriber DB
CREATE SUBSCRIPTION mysub CONNECTION 'dbname=foo host=bar user=repuser' PUBLICATION mypub;
You might want to try Bucardo, which is an open source software to synchronize rows between tables even if they are in a remote location. It's a very simple software, and it is capable of creating one-way synchronization relationships as well.
Check out http://bucardo.org/wiki/Bucardo
You cannot get anything useful by copying individual tables files in the data directory. If you want to replicate selected tables, there are a number of good options.
http://wiki.postgresql.org/wiki/Replication,_Clustering,_and_Connection_Pooling
Help me to chouse a simple (lightweight) solution to the master-slave replication of one table between two Postgresql databases. The table contains a large object.
Here you'll find a very good overview of the replication tools for PostgreSQL. Please, take a look and hopefully you'll be able to pick one.
Otherwise, if you need something really lightweight, you can do it yourself. You'll need a trigger and a couple of functions, a dblink module if you need almost immediate changes propagation, otherwise you can survive with cron.