### Database links vs. subreports in one-to-many situations

When two tables in a report have a one-to-many relationship, the program retrieves the data in different ways depending on:

- data source
- index situation
- record selection criteria
- whether you are creating a single report based on linked tables or a primary report that contains a subreport.

When you are considering whether to use a subreport or linked tables, you need to understand the ramifications of each. These issues are discussed fully in Performance considerations in one-to-many links.

As a general rule, if you have:

- indexed tables
- linked indexed fields
- range limiting record selection criteria based on the indexed fields

the program needs to read the same number of records whether you are linking tables in a single report or using subreports. Since each subreport is run as a separate report, linked tables may have a performance advantage. See Indexed tables.

Seagate Software, Inc. http://www.seagatesoftware.com Please send comments to: techpubs@seagatesoftware.com