Summary information |
|
|---|---|
Default value |
5 |
Range of values |
0–100 |
Status |
Dynamic |
Display level |
Intermediate |
Required role |
System administrator |
Configuration group |
SQL Server Administration |
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 applied only to pages for tables that have variable-length columns.
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 Series: Locking and Concurrency Control.
