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If Your Version is 11.5, 11.9.x, or 12.0

• Using New Wide Data Sizes with Open Client

• Wide Columns and Optimizer Statistics

• Wide Columns with col_length() and datalength()

Change in Truncation Behavior

Previous releases of Adaptive Server had a column-length limit of 255 bytes.

The 12.5 release of Adaptive Server allows you to create columns using

char,

varchar, binary, and varbinary data up to 16294 bytes long, depending on the

logical page size your server uses. Because of this, data that was truncated at

255 characters for earlier releases of Adaptive Server is no longer truncated. If

your application depended on this truncation, the result set it receives may no

longer be accurate. In the following example,

col1 and col2 are each 200

characters long, and

col3 is 255 characters long:

select * from t1 where col1 + col2 = col3

If col1 and col2 each hold 200 characters, their concatenation results in a 400-

character string. Previous releases of Adaptive Server truncate this to 255

characters, and the sum of

col1 and col2 might match col3. However, for the

12.5 release of Adaptive Server, the product of

col1 and col2 is 400 characters,

and will never match a

col3 that is 255 characters long.

Character and binary expressions can produce a result up to 16384 bytes long.

Data that is over this length is truncated.

Note See the section on New Table Limits in Chapter 6 of this manual.

Using New Wide Data Sizes with Open Client

Adaptive Server and Open Client interact depending on how you determine

Open Client’s capabilities. Capabilities describe features that a client/server

connection supports. In particular, capabilities describe the types of requests

that an application sends on a specific connection and the types of server

responses that a server returns on a specific connection. Before you use Open

Client with the wider limits allowed by Adaptive Server version 12.5, you must

enable the Open Client capability for these limits. See your Open Client

documentation for information about enabling the wide-table capabilities.

Note DB Library cannot use the wide limits for Adaptive Server version 12.5

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Seagate ST43401N/ND Guida di Installazione Pagina 66