AVG_DATA_BLOCKS_PER

From: Don Doo <doodon_at_gmail.com>
Date: Thu, 23 Nov 2006 17:01:19 -0500
Message-ID: <36f8e4b00611231401q37127037hb949b67b587414d2@mail.gmail.com>

Hi,

I am investigating a query performance and found the values for AVG_DATA_BLOCKS_PER_KEY and AVG_LEAF_BLOCKS_PER_KEY are zero for the index measurement_k4. Could somebody please explain why it is happening?

1 select a.index_name, b.num_rows, b.blocks,

  2      a.avg_data_blocks_per_key,a.avg_leaf_blocks_per_key,
  3      a.clustering_factor
  4          from ALL_indexes a, ALL_tables b
  5          where a.table_name=b.table_name
  6*        aND INDEX_NAME LIKE 'MEASUREMENT%'

SQL> /

INDEX_NAME                       NUM_ROWS     BLOCKS AVG_DATA_BLOCKS_PER_KEY

AVG_LEAF_BLOCKS_PER_KEY CLUSTERING_FACTOR
------------------------------ ---------- ---------- -----------------------

MEASUREMENT_K2            51850444    1410365
1463                       8          52315549
MEASUREMENT_K3            51850444    1410365
1                       1          48979653
MEASUREMENT_K4            51850444    1410365
0                       0          49370150

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http://www.freelists.org/webpage/oracle-l Received on Thu Nov 23 2006 - 16:01:19 CST

AVG_DATA_BLOCKS_PER_KEY is zero