JDBC Limitations

Here are some limitations of JDBC encountered during the implementations of Jaqy.

32-bit Row Position and Activity Count

There are a number of places where the use of 32-bit int that are very limited in today’s Big Data world.

• In ResultSet

  • boolean absolute(int row)
  • int getRow()
  • There are also no mechanisms for obtaining the ResultSet row count without having to either scan the rows or to use the positioning to find out the row count. In ResultSet.TYPE_FORWARD_ONLY, the only way to get the row count is by scanning rows.

• In Statement,

  • int getUpdateCount()

Lacking Good Type Information

The only thing in JDBC that provides type information is DatabaseMetadata.getTypeInfo(). Yet it is not all that useful.

• There can be multiple types mapped to a single JDBC type without a way of indicating the default one to use. For instance, in PostgreSQL, both int4 and serial maps to Types.INTEGER.
• For types such as VARCHAR(100) CHARACTER SET LATIN, there are basically no way to infer the type name based on the type information.

Poor Array and Struct Type Support

JDBC has very poor Array and Struct support.

ResultSetMetaData and ParameterMetaData have only the basic type information, without any mechanism obtaining the element or attribute types. Needless to say, there is no way to obtain nested Array or Struct information.

There is also no way to obtain the Struct attributes.