RelationalDBDesign 




Advanced Tuning  «Prev 
Setting PCTFREE for optimal performance

Table Statistics

Oracle lists the following table statistics in the DBA_INDEXES, USER_INDEXES and ALL_INDEXES data dictionary views:
  1. Number of rows
  2. Number of chained rows
  3. Exact number of data blocks storing data
  4. Exact number of data blocks allocated, but never used
  5. Average row length, including row overhead
  6. Average available free space in each data block


  1. DBA_TAB_MODIFICATIONS
  2. ALL_TAB_MODIFICATIONS
  3. USER_TAB_MODIFICATIONS
The views listed above describe tables that have been modified since the last time table statistics were gathered on them. They are not populated immediately, but after a time lapse (usually 3 hours).