Millises järjekorras peaksid SQL-tabeli koosneva võtme väljad organiseerima, et optimeerida otsingut ja andmete terviklikkust?

Organizing a composite key in an SQL table, the order of fields is important for optimizing search and ensuring data integrity:

1. Fields with the highest selectivity (i.e., those that best separate data) are placed first. This speeds up search and indexing.
2. It is also advisable to place first the fields most frequently used in WHERE or JOIN conditions.
3. If the key consists of multiple fields, the order should reflect the data access logic.

For example, if you have a composite key of (Country, City, Street), and queries are more often filtered by Country and City, such an order is justified. If filtered more by City, consider a permutation.

Thus, the correct order of fields in a composite key increases index efficiency and supports data integrity.