Jon Gurgul's Blog

Tag: Row

  • SQL Index dm_db_index_xxx_stats

    —

    by

    Jon Gurgul
    in

    There are 3 dm_db_index_xxx_stats objects that can be used to check and investigate index information. sys.dm_db_index_usage_stats can be used to see how beneficial the index is, and its related maintenance cost. Note that this information is reset upon instance restart. The final two index stats objects provide information on the physical and operational statistics of…

  • SQL Server Row Internals

    —

    by

    Jon Gurgul
    in

    Row Storage A Row is stored on a Page which is 8192 Bytes, and this is broken down in two key areas when considering physical storage. Firstly on all pages there is a 96 Byte Header. In addition to this we also need to store the Row structure as well as its location in the…

  • SQL Servers Virtual Columns and Row Cracking

    —

    by

    Jon Gurgul
    in

    In order to access row structures there are several functions within SQL Server that are beneficial. I have listed these below with the descriptions taken from the actual functions. sys.fn_GetRowsetIdFromrowdump — Cracks the output of %%rowdump%% virtual column and returns the rowset id sys.fn_rowdumpCracker — Cracks the output of %%rowdump%% virtual column sys.fn_physlocFormatter — Formats the…