When is it advantageous to place indexes in a database?

Placing indexes in a database is particularly advantageous when there are more read operations than write operations. Indexes are designed to improve the speed of data retrieval, allowing the database to access rows more quickly by referencing the indexed columns. When a database is queried frequently, having indexes can significantly enhance performance, as it reduces the time it takes to locate and return the requested data.

In scenarios where read operations outnumber write operations, the benefits of indexing are realized without imposing a heavy burden on write operations, which can be subjected to additional overhead as indexes must be updated whenever the data changes. Therefore, a balanced approach that focuses on read efficiency during high-volume querying makes the presence of indexes highly effective.

When considering the size of the database, while smaller databases might not need extensive indexing due to their manageable size, larger databases with significant amounts of data can greatly benefit from indexing, especially during searches.

Conclusively, focusing on optimizing read performance is the key reason indexing is strategically employed when read actions are prevalent in a database's usage pattern.