INF: Enhancement to Trace Flag 1140

ID: Q174085

The information in this article applies to:

Microsoft SQL Server version 6.5

SUMMARY

Trace flag 1140 was originally designed to eliminate the extent-chain scan when attempting to allocate a page to an existing table. One of the most significant side effects of this trace flag was that space in partially- filled extents never got reclaimed; the size of database can grow rapidly where most of the pages in each extent remains unused.

MORE INFORMATION

The enhancement is to limit the extent-chain scan, based on how densely- filled the extents for a table are (density=indused/indreserved). If density >= 90 percent, then stop the extent-chain scan after 'n' allocation pages are searched, where 'n' is (100-density) < 2 (that is, it varies from 1 to 40 as density varies from 90 to 100).


Keywords          : kbusage SSrvGen 
Version           : WINDOWS:6.50
Platform          : winnt 
Issue type        : kbinfo

Last Reviewed: April 20, 1999