Rows in Nonfragmented Tables

The database server can store rows that are longer than a page. The database server also supports the VARCHAR data type, which results in rows of varying length. As a result, rows do not conform to a single format.

Rows within a table are not necessarily the same length if the table contains one or more columns of type VARCHAR. In addition, the length of a row in such a table might change when an end user modifies data contained in the VARCHAR column.

The length of a row can be greater than a page.

TEXT and BYTE data is not stored within the data row. Instead, the data row contains a 56-byte descriptor that points to the location of the data. The descriptor can point to a dbspace page.

The descriptor can point to a blobspace blobpage.

For instructions about how to estimate the length of fixed-length and variable-length data rows, see your IBM® Informix® Performance Guide.


Copyright© 2018 HCL Technologies Limited