Fix replication errors with tables containing generated columns

[danolivo]

PostgreSQL generated columns (GENERATED ALWAYS AS ... STORED) were causing errors during Spock replication. The issue occurred because generated columns were being treated as regular columns during:

• Initial table synchronization (COPY operations)
• Logical replication protocol messages
• Default value filling for missing attributes
• Conflict resolution and tuple processing

Generated columns should not be replicated since they are computed automatically on the target database based on their definition.

Solution:
Add checks for attgenerated flag alongside existing attisdropped checks throughout the codebase to skip generated columns in:

• spock_sync.c: COPY attribute list construction
• spock_apply_heap.c: Default value filling
• spock_proto_native.c: Native protocol tuple serialization
• spock_proto_json.c: JSON protocol handling
• spock_conflict.c: Conflict tuple formatting
• spock_jsonb_utils.c: JSONB conversion utilities
• spock_functions.c: Replication set table info
• spock_repset.c: Attribute name lookup

Test Coverage:
Added regression test in sync_table.sql that verifies:

• Table with STORED generated column can be added to replication set
• Initial table synchronization works correctly via sub_resync_table()
• Generated column values are correctly computed on subscriber
• Both initial sync and ongoing replication handle generated columns

[coderabbitai]

Important

Review skipped

Auto reviews are disabled on base/target branches other than the default branch.

Please check the settings in the CodeRabbit UI or the .coderabbit.yaml file in this repository. To trigger a single review, invoke the @coderabbitai review command.

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro Plus

Run ID: e3349c8d-f73a-47ca-af53-eed98f13de91

You can disable this status message by setting the reviews.review_status to false in the CodeRabbit configuration file.

Use the checkbox below for a quick retry:

• 🔍 Trigger review

---

Thanks for using CodeRabbit! It's free for OSS, and your support helps us grow. If you like it, consider giving us a shout-out.

❤️ Share

• X
• Mastodon
• Reddit
• LinkedIn

_{Comment @coderabbitai help to get the list of available commands.}

[codacy-production]

Up to standards ✅

🟢 Issues 0 issues

Results:
0 new issues

View in Codacy

🟢 Metrics 0 complexity · -2 duplication

Metric	Results
Complexity	0
Duplication	-2

View in Codacy

_{NEW Get contextual insights on your PRs based on Codacy's metrics, along with PR and Jira context, without leaving GitHub. Enable AI reviewer
TIP This summary will be updated as you push new changes.}