Hi hackers, I created a small PoC. Please see the attached patches.
REQUIREMENT Before patching them, patches in [1] must also be applied. DIFFERENCES FROM PREVIOUS DESCRIPTIONS * LRG is now implemented as SQL functions, not as a contrib module. * New tables are added as system catalogs. Therefore, added tables have oid column. * The node_id is the strcat of system identifier and dbid. HOW TO USE In the document patch, a subsection 'Example' was added for understanding LRG. In short, we can do 1. lrg_create on one node 2. lrg_node_attach on another node Also attached is a test script that constructs a three-nodes system. LIMITATIONS This feature is under development, so there are many limitations for use case. * The function for detaching a node from a group is not implemented. * The function for removing a group is not implemented. * LRG does not lock system catalogs and databases. Concurrent operations may cause inconsistent state. * LRG does not wait until the upstream node reaches the latest lsn of the remaining nodes. * LRG does not support initial data sync. That is, it can work well only when all nodes do not have initial data. [1]: https://commitfest.postgresql.org/38/3610/ Best Regards, Hayato Kuroda FUJITSU LIMITED
v1-0001-PoC-implement-LRG.patch
Description: v1-0001-PoC-implement-LRG.patch
v1-0002-add-doc.patch
Description: v1-0002-add-doc.patch
test.sh
Description: test.sh
