InstantForum.NET v2.9.0SQLServerCentralhttp://www.sqlservercentral.com/Forums/notifications@sqlservercentral.comSat, 25 May 2013 13:42:58 GMT20http://www.sqlservercentral.com/Forums/Topic1123858-32-1.aspx[quote][b]Tom.Thomson (6/13/2011)[/b][hr]Good question.But one major niggle and one minor niggle:Major niggle: if page compression is enabled on a table already containing data, each page is rebuilt and evaluated for page compression; page compression can occur here (unless I've got it wrong) and may make the data fit into fewer pages than if only row compression occurred. So the answer always applies to pages which are empty/unallocated when compression is enabled, but not always to pages which already contain data when compression is enabled.Minor niggle: page compression won't occur even when a new row doesn't fit if the engine determines that page compression would not free up a significant amount of space.edit: SCTEs[/quote]Thanks Tom for adding these points, very useful really.Mon, 13 Jun 2011 20:53:45 GMTmohammed moinudheenhttp://www.sqlservercentral.com/Forums/Topic1123858-32-1.aspxSteve, this is a really good question. Thanks!Mon, 13 Jun 2011 19:26:43 GMTWayneShttp://www.sqlservercentral.com/Forums/Topic1123858-32-1.aspxGood question and great topic, thanks.Mon, 13 Jun 2011 12:36:41 GMTCliff Joneshttp://www.sqlservercentral.com/Forums/Topic1123858-32-1.aspxNice question!See Data Compression: Strategy, Capacity Planning and Best Practices in ( http://msdn.microsoft.com/en-us/library/dd894051%28v=sql.100%29.aspx )Mon, 13 Jun 2011 10:59:44 GMTRafael Krisllerhttp://www.sqlservercentral.com/Forums/Topic1123858-32-1.aspxMissed it! But learned some important detail.Great question!Mon, 13 Jun 2011 10:34:29 GMTPeter Trasthttp://www.sqlservercentral.com/Forums/Topic1123858-32-1.aspx[quote][b]Tom.Thomson (6/13/2011)[/b][hr]Good question.But one major niggle and one minor niggle:Major niggle: if page compression is enabled on a table already containing data, each page is rebuilt and evaluated for page compression; page compression can occur here (unless I've got it wrong) and may make the data fit into fewer pages than if only row compression occurred. So the answer always applies to pages which are empty/unallocated when compression is enabled, but not always to pages which already contain data when compression is enabled.Minor niggle: page compression won't occur even when a new row doesn't fit if the engine determines that page compression would not free up a significant amount of space.edit: SCTEs[/quote]Fair points. I've added a note that this is after the initial page compression setting.Mon, 13 Jun 2011 09:16:40 GMTSteve Jones - SSC Editorhttp://www.sqlservercentral.com/Forums/Topic1123858-32-1.aspxThis question is little tricky i.e When compression is enabled on server then only page compression can occur .if page compression is not enabled and if page is full and a new row is added then compression may not worked .Mon, 13 Jun 2011 07:41:59 GMTashjoe7http://www.sqlservercentral.com/Forums/Topic1123858-32-1.aspxGood question.But one major niggle and one minor niggle:Major niggle: if page compression is enabled on a table already containing data, each page is rebuilt and evaluated for page compression; page compression can occur here (unless I've got it wrong) and may make the data fit into fewer pages than if only row compression occurred. So the answer always applies to pages which are empty/unallocated when compression is enabled, but not always to pages which already contain data when compression is enabled.Minor niggle: page compression won't occur even when a new row doesn't fit if the engine determines that page compression would not free up a significant amount of space.edit: SCTEsMon, 13 Jun 2011 07:01:01 GMTL' Eomot Inverséhttp://www.sqlservercentral.com/Forums/Topic1123858-32-1.aspxExcellent question.Mon, 13 Jun 2011 06:36:46 GMTSQLRNNRhttp://www.sqlservercentral.com/Forums/Topic1123858-32-1.aspxI thought I had the correct answer, but the subtlety of the question caught me out.Mon, 13 Jun 2011 02:25:06 GMTpaul s-306273http://www.sqlservercentral.com/Forums/Topic1123858-32-1.aspxGood question, with some really plausible wrong answers.Mon, 13 Jun 2011 01:37:59 GMTStewart "Arturius" Campbellhttp://www.sqlservercentral.com/Forums/Topic1123858-32-1.aspx[quote][b]Koen Verbeeck (6/12/2011)[/b][hr]Great question, with subtle differences between the answers :-)[/quote]I agree with you, it is a little tough to get this answer right :)Sun, 12 Jun 2011 11:55:12 GMTmohammed moinudheenhttp://www.sqlservercentral.com/Forums/Topic1123858-32-1.aspxGreat question, with subtle differences between the answers :-)Sun, 12 Jun 2011 02:47:06 GMTKoen Verbeeckhttp://www.sqlservercentral.com/Forums/Topic1123858-32-1.aspxComments posted to this topic are about the item [B]<A HREF="/questions/Design+and+Theory/73557/">Page Compression</A>[/B]Sat, 11 Jun 2011 21:28:38 GMTSteve Jones - SSC Editor