JDBC driver taxonomy: According to Sun/Oracle’s classic classification, how many JDBC driver Types are defined (Type 1 through Type N)?

Introduction / Context:
JDBC drivers historically have been grouped into “Types” that describe how a driver translates JDBC API calls into database-specific operations. Knowing the number and nature of these Types helps clarify compatibility and deployment implications for Java applications.

Given Data / Assumptions:

• The classification originates from Sun Microsystems and persists in documentation.
• Types are numbered sequentially and commonly referenced in interviews and textbooks.
• We are asked for the count of Types in the classic scheme.

Concept / Approach:

There are four classic Types: Type 1 (JDBC-ODBC bridge), Type 2 (native-API partly Java driver), Type 3 (network protocol driver using middleware), and Type 4 (thin driver using native database protocol over the network). Modern practice overwhelmingly favors Type 4 drivers for portability and simple deployment.

Step-by-Step Solution:

Verification / Alternative check:

Check any mainstream JDBC driver documentation; the Type is often stated (for example, PostgreSQL and MySQL drivers are Type 4).

Why Other Options Are Wrong:

One/Two/Three: omit one or more established Types and do not reflect the historical taxonomy.

Common Pitfalls:

Assuming the Type determines feature completeness; real capability depends on the specific driver implementation and database.

Final Answer:

Four