MX 2.x)

object by using one of the following properties, depending on the LOB column type:

LOB Column Type Property name

BLOB blobTableName

CLOB clobTableName

For more information about using these properties, see LOB Table Name Properties.

Reserving Data Locators

A data locator is the reference pointer value (SQL LARGEINT data type) that is substituted for the BLOB or CLOB column

in the base table definition. Each object stored into the LOB table is assigned a unique data locator value. Because the

LOB table is a shared resource among all accessors that use the particular LOB table, reserving data locators reduces

contention for getting the next value. By using a default setting of 100 reserved data locators, each JVM instance can

insert 100 large objects (not chunks) before needing a new allocation.

You can specify the number of data locators (n) to reserve for your application by using the JDBC/MX system

property jdbcmx.reserveDataLocators in the command line.

For information about specifying this property, see Setting the reserveDataLocators Property.

Storing CLOB Data

Inserting CLOB Columns by Using the Clob Interface

Writing ASCII or Unicode Data to a CLOB Column

Inserting CLOB Data by Using the PreparedStatement Interface

Inserting a Clob Object by Using the setClob Method

Inserting CLOB Columns by Using the Clob Interface

When you insert a row containing a CLOB data type, and before the column can be updated with real CLOB data, you can

insert a row that has an "empty" CLOB value . You can insert an empty CLOB value in a NonStop SQL/MX database by

specifying EMPTY_CLOB() function for the CLOB column in the insert statement.

The JDBC/MX driver scans the SQL string for the EMPTY_CLOB() function and substitutes the next-available data

locator.

Then, you must obtain the handle to the empty CLOB column by selecting the CLOB column for update.

Note the limitation: Do not rename the CLOB column in the select query.

The following code illustrates how to obtain the handle to an empty CLOB column:

Clob myClob = null;

Statement s = conn.createStatement();

ResultSet rs = s.executeQuery("Select myClobColumn

from myTable where ….for update");

if (rs.next())

myClob = rs.getClob(1);