Hello, Here is a patch that supports replication of global object commands, these include ROLE statements, database statements and tablespace statements. The patch should be applied on top of the v13 DDL replication patch set that ZJ Hou sent in the previous email.
Global objects commands are different from other DDL commands in that: 1. Global objects commands are allowed to be executed in any databases 2. Global objects are not schema qualified 2. Global objects commands are not captured by event triggers This patch supports global objects commands replication by WAL logging the command using the same function for DDL logging - LogLogicalDDLMessage, towards the end of standard_ProcessUtility. Because global objects are not schema qualified, we can skip the deparser invocation and directly log the original command string for replay on the subscriber. A key problem is global objects can get inconsistent between the publisher and the subscriber if a command changes the global object in a database (on the source side) which doesn't configure logical replication. I think we can work on the following directions in order to avoid such inconsistency: 1. Introduce a publication option for global objects command replication and document that logical replication of global objects commands is preferred to be configured on all databases. Otherwise inconsistency can happen if a command changes the global object in a database which doesn't configure logical replication. 2. Introduce database cluster level logical replication to avoid such inconsistency, this is especially handy when there is a large number of databases to configure for logical replication. Regards, Zheng
0005-Support-replication-of-global-object-commands-these-.patch
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