mirror of
https://github.com/timescale/timescaledb.git
synced 2025-05-15 10:11:29 +08:00
bea2613455
Chunk constraints are now added after a chunk has been copied from one data node to another. The constraints are added when the chunk is made visible on the destination node, i.e., after data has been copied and the chunk's metadata is created. As an alternative, the constraints could be added when the chunk table is first created, but before the metadata for the chunk is added. This would have the benefit of validating each copied (inserted) row against the constraints during the data copy phase. However, this would also necessitate decoupling the step of creating the constraint metadata from the creation of the actual constraints since the other chunk metadata that is referenced does not yet exist. Such decoupling would require validating that the metadata actually matches the constraints of the table when the metadata is later created. One downside of adding the constraints after data copying is that it necessitates validating all the chunk's rows against the constraints after insertion as opposed to during insertion. If this turns out to be a performance issue, validation could be initially deferred. This is left as a future optimization.