bretton.dev
A community based topic aggregation platform built on atproto
feat(db): add migration for comment deletion metadata
Add migration 021 that:
- Creates deletion_reason enum type (author, moderator)
- Adds deletion_reason and deleted_by columns to comments table
- Backfills existing deleted comments as author-deleted
- Removes deleted_at IS NULL filter from thread indexes to preserve structure
- Adds indexes for deletion_reason and deleted_by for moderation queries
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude <noreply@anthropic.com>
+66
internal/db/migrations/021_add_comment_deletion_metadata.sql
+66
internal/db/migrations/021_add_comment_deletion_metadata.sql
···
1
+
-- +goose Up
2
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-- Add deletion reason tracking to preserve thread structure while respecting privacy
3
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-- When comments are deleted, we blank content but keep the record for threading
4
+
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-- Create enum type for deletion reasons
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CREATE TYPE deletion_reason AS ENUM ('author', 'moderator');
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+
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-- Add new columns to comments table
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ALTER TABLE comments ADD COLUMN deletion_reason deletion_reason;
10
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ALTER TABLE comments ADD COLUMN deleted_by TEXT;
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+
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-- Add comments for new columns
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COMMENT ON COLUMN comments.deletion_reason IS 'Reason for deletion: author (user deleted), moderator (community mod removed)';
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COMMENT ON COLUMN comments.deleted_by IS 'DID of the actor who performed the deletion';
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+
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-- Backfill existing deleted comments as author-deleted
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-- This handles existing soft-deleted comments gracefully
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UPDATE comments
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SET deletion_reason = 'author',
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deleted_by = commenter_did
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WHERE deleted_at IS NOT NULL AND deletion_reason IS NULL;
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+
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-- Modify existing indexes to NOT filter deleted_at IS NULL
24
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-- This allows deleted comments to appear in thread queries for structure preservation
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-- Note: We drop and recreate to change the partial index condition
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+
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-- Drop old partial indexes that exclude deleted comments
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DROP INDEX IF EXISTS idx_comments_root;
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DROP INDEX IF EXISTS idx_comments_parent;
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DROP INDEX IF EXISTS idx_comments_parent_score;
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DROP INDEX IF EXISTS idx_comments_uri_active;
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+
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-- Recreate indexes without the deleted_at filter (include all comments for threading)
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CREATE INDEX idx_comments_root ON comments(root_uri, created_at DESC);
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CREATE INDEX idx_comments_parent ON comments(parent_uri, created_at DESC);
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CREATE INDEX idx_comments_parent_score ON comments(parent_uri, score DESC, created_at DESC);
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CREATE INDEX idx_comments_uri_lookup ON comments(uri);
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+
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-- Add index for querying by deletion_reason (for moderation dashboard)
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CREATE INDEX idx_comments_deleted_reason ON comments(deletion_reason, deleted_at DESC)
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WHERE deleted_at IS NOT NULL;
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+
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-- Add index for querying by deleted_by (for moderation audit/filtering)
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CREATE INDEX idx_comments_deleted_by ON comments(deleted_by, deleted_at DESC)
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WHERE deleted_at IS NOT NULL;
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+
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-- +goose Down
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-- Remove deletion metadata columns and restore original indexes
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+
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DROP INDEX IF EXISTS idx_comments_deleted_by;
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DROP INDEX IF EXISTS idx_comments_deleted_reason;
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DROP INDEX IF EXISTS idx_comments_uri_lookup;
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DROP INDEX IF EXISTS idx_comments_parent_score;
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DROP INDEX IF EXISTS idx_comments_parent;
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DROP INDEX IF EXISTS idx_comments_root;
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+
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-- Restore original partial indexes (excluding deleted comments)
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CREATE INDEX idx_comments_root ON comments(root_uri, created_at DESC) WHERE deleted_at IS NULL;
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CREATE INDEX idx_comments_parent ON comments(parent_uri, created_at DESC) WHERE deleted_at IS NULL;
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CREATE INDEX idx_comments_parent_score ON comments(parent_uri, score DESC, created_at DESC) WHERE deleted_at IS NULL;
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CREATE INDEX idx_comments_uri_active ON comments(uri) WHERE deleted_at IS NULL;
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+
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ALTER TABLE comments DROP COLUMN IF EXISTS deleted_by;
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ALTER TABLE comments DROP COLUMN IF EXISTS deletion_reason;
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DROP TYPE IF EXISTS deletion_reason;