[chore] Use bulk updates + fewer loops in status rethreading migration

internal/db/bundb/migrations/util.go

@@ -66,98 +66,6 @@ func doWALCheckpoint(ctx context.Context, db *bun.DB) error {
 	return nil
 }
 
-// batchUpdateByID performs the given updateQuery with updateArgs
-// over the entire given table, batching by the ID of batchByCol.
-func batchUpdateByID(
-	ctx context.Context,
-	tx bun.Tx,
-	table string,
-	batchByCol string,
-	updateQuery string,
-	updateArgs []any,
-) error {
-	// Get a count of all in table.
-	total, err := tx.NewSelect().
-		Table(table).
-		Count(ctx)
-	if err != nil {
-		return gtserror.Newf("error selecting total count: %w", err)
-	}
-
-	// Query batch size
-	// in number of rows.
-	const batchsz = 5000
-
-	// Stores highest batch value
-	// used in iterate queries,
-	// starting at highest possible.
-	highest := id.Highest
-
-	// Total updated rows.
-	var updated int
-
-	for {
-		// Limit to batchsz
-		// items at once.
-		batchQ := tx.
-			NewSelect().
-			Table(table).
-			Column(batchByCol).
-			Where("? < ?", bun.Ident(batchByCol), highest).
-			OrderExpr("? DESC", bun.Ident(batchByCol)).
-			Limit(batchsz)
-
-		// Finalize UPDATE to act only on batch.
-		qStr := updateQuery + " WHERE ? IN (?)"
-		args := append(slices.Clone(updateArgs),
-			bun.Ident(batchByCol),
-			batchQ,
-		)
-
-		// Execute the prepared raw query with arguments.
-		res, err := tx.NewRaw(qStr, args...).Exec(ctx)
-		if err != nil {
-			return gtserror.Newf("error updating old column values: %w", err)
-		}
-
-		// Check how many items we updated.
-		thisUpdated, err := res.RowsAffected()
-		if err != nil {
-			return gtserror.Newf("error counting affected rows: %w", err)
-		}
-
-		if thisUpdated == 0 {
-			// Nothing updated
-			// means we're done.
-			break
-		}
-
-		// Update the overall count.
-		updated += int(thisUpdated)
-
-		// Log helpful message to admin.
-		log.Infof(ctx, "migrated %d of %d %s (up to %s)",
-			updated, total, table, highest)
-
-		// Get next highest
-		// id for next batch.
-		if err := tx.
-			NewSelect().
-			With("batch_query", batchQ).
-			ColumnExpr("min(?) FROM ?", bun.Ident(batchByCol), bun.Ident("batch_query")).
-			Scan(ctx, &highest); err != nil {
-			return gtserror.Newf("error selecting next highest: %w", err)
-		}
-	}
-
-	if total != int(updated) {
-		// Return error here in order to rollback the whole transaction.
-		return fmt.Errorf("total=%d does not match updated=%d", total, updated)
-	}
-
-	return nil
-}
-
 // convertEnums performs a transaction that converts
 // a table's column of our old-style enums (strings) to
 // more performant and space-saving integer types.