Microsoft KB Archive/174085

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INF: Enhancement to Trace Flag 1140

Article ID: 174085

Article Last Modified on 10/3/2003


  • Microsoft SQL Server 6.5 Standard Edition

This article was previously published under Q174085


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.


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: kbinfo kbusage KB174085