default exp_row_size percent

Summary information

Default value

5

Range of values

0–100

Status

Dynamic

Display level

Intermediate

Required role

System Administrator

default exp_row_size percent reserves space for expanding updates in data-only-locked tables, to reduce row forwarding. An expanding update is any update to a data row that increases the length of the row. Data rows that allow null values or that have variable-length columns may be subject to expanding updates. In data-only-locked tables, expanding updates can require row forwarding if the data row increases in size so that it no longer fits on the page.

The default value, sets aside 5 percent of the available data page size for use by expanding updates. Since 2002 bytes are available for data storage on pages in data-only-locked tables, this leaves 100 bytes for expansion. This value is only applied to pages for tables that have variable-length columns.

Valid values are 0–99. Setting default exp_row_size percent to 0 means that all pages are completely filled and no space is left for expanding updates.

default exp_row_size percent is applied to data-only-locked tables with variable-length columns when exp_row_size is not explicitly provided with create table or set with sp_chgattribute. If a value is provided with create table, that value takes precedence over the configuration parameter setting. See the Performance and Tuning Guide for more information.