When designing a schema, limit the sizes of fields so that planned queries will fit within the size limits. Most simple queries on a single table will fit within the 8000-byte limit. This is because the table row definition itself must fit within the similar 8080-bytes for overall table row size. Also note that complex queries on even a single table (such as queries involving many OR clauses) may overflow the limit. Schema design and query design must work together carefully if complex queries are an important part of the application.
For further information, see Query Size Limit.