When any of the following data types is defined in a table and the actual size of the data of any of these data types is equal to or greater than 256 bytes, the normal procedure results in each row of data being stored on multiple pages:

• VARCHAR
• MVARCHAR
• NVARCHAR

Figure 3-6 shows the data storage method that is used normally.

Figure 3-6 Normal data storage method when the actual data size of a variable-size character string is at least 256 bytes

As illustrated, data that is not part of variable-size character strings and data belonging to variable-size character string are stored on different pages, which reduces the data storage efficiency. In this case, you can improve the data storage efficiency by specifying the no-split option. When the no-split option is specified, the system stores each entire row on the same page, even if the actual data size of a variable-size character string is equal to or greater than 256 bytes. Figure 3-7 shows the data storage method that is used when the no-split option is specified.

Figure 3-7 Data storage method used when the no-split option is specified

Explanation

The no-split option stores all data from a row on the same page, which improves the data storage efficiency as compared to when the no-split option is not specified.

The no-split option is specified with the NO SPLIT option in the CREATE TABLE or CREATE TYPE. For details about the no-split option, see the HiRDB Version 8 Installation and Design Guide.