WIP: high load unique index

pkg/migrations/op_set_unique.go

@@ -5,6 +5,7 @@ package migrations
 import (
 	"context"
 	"fmt"
+	"time"
 
 	"github.com/lib/pq"
 	"github.com/xataio/pgroll/pkg/db"
@@ -30,6 +31,11 @@ func (o *OpSetUnique) Start(ctx context.Context, conn db.DB, latestSchema string
 		return nil, fmt.Errorf("failed to add unique index: %w", err)
 	}
 
+	err := ensureIndexIsValid(ctx, conn, s.Name, o.Name)
+	if err != nil {
+		return nil, fmt.Errorf("failed to validate unique index: %w", err)
+	}
+
 	return table, nil
 }
 
@@ -83,3 +89,43 @@ func addUniqueIndex(ctx context.Context, conn db.DB, table, column, name string)
 
 	return err
 }
+
+func ensureIndexIsValid(ctx context.Context, conn db.DB, schemaname string, indexname string) error {
+	invalid, err := isIndexInvalid(ctx, conn, schemaname, indexname)
+	if err != nil {
+		return err
+	}
+	for invalid {
+		time.Sleep(1 * time.Second)
+		invalid, err = isIndexInvalid(ctx, conn, schemaname, indexname)
+		if err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func isIndexInvalid(ctx context.Context, conn db.DB, schemaname string, indexname string) (bool, error) {
+	var exists bool
+	rows, err := conn.QueryContext(ctx, `
+		SELECT EXISTS (
+			SELECT *
+			FROM pg_catalog.pg_index
+			WHERE indexrelid = $1::regclass
+			AND indisvalid = false)`,
+		fmt.Sprintf("%s.%s", pq.QuoteIdentifier(schemaname), pq.QuoteIdentifier(indexname)))
+	if err != nil {
+		return false, fmt.Errorf("getting invalid index with name %q: %w", indexname, err)
+	}
+	if err := db.ScanFirstValue(rows, &exists); err != nil {
+		return false, fmt.Errorf("scanning invalid index with name %q: %w", indexname, err)
+	}
+
+	if exists {
+		fmt.Printf("%s Invalid, waiting for a sec\n", fmt.Sprintf("%s.%s", pq.QuoteIdentifier(schemaname), pq.QuoteIdentifier(indexname)))
+	} else {
+		fmt.Println("VALID")
+	}
+
+	return exists, nil
+}