The article explores the impact of node count on the creation of indexes in Cloud Spanner databases. Adding nodes before index backfill starts is effective in speeding up the process, but adding nodes during the process does not improve performance.

Additionally, reducing nodes during the process could cause up to 100% of total CPU utilization.

The study also confirms that Cloud Spanner defines parallelism degree and resource limit for index backfill based on instance node count and available CPU, and it is not possible to speed-up the index creation process by adding more resources.

The tests conducted in the study highlight the importance of careful planning and strategic decision-making when it comes to modifying indexes in Cloud Spanner.