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Message Posted: Wed, 19 Mar 2003 @ 18:57:52 GMT


     
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Subj:   Re: Real size of the table
 
From:   Dennis Calkins

Hi,

If you don't mind a little math you can deduce the information from the SHOWBLOCKS command in Ferret.

Start the FERRET utility from the supervisor.

the default is to do every table on the system.

However, if you want you can select a SPECIFIC table you can specify

scope table "database.tablename" 0

Once setting the

then issue the showblocks command (/s is the default )

showblocks /s { shows just the Primrary Data table )

showblocks /m { shows all the subtables on separate lines }

the show blocks display is quite wide and you need both sides of the display.

The left side of each line has the subtable id. (this a /m display )

+------------
|
|
|
|  Table ID
|
+------------
|    0   135     <<<--- internal table id of selected table.
|
|       1024     <<<--- Primary data table
|       1028     <<<--- First secondary index
|       1032     <<<--- Second Secondary Index
|       2048     <<<---- Fallback data table from
|       2052     <<<---- fallback of First secondary index
|       2056     <<<---- Fallback of Second Secondary index
+------------

If you have more than 2 amps per fallback cluster you may see 3072, and 4096 and so on subtables as well.

at the right side of the of the display you will find.

+-----------------+-----------+-----------+
|   Data block    |   Total   |   Total   |
| size statistics |   Number  |   Number  |
+    (sectors)    |     of    |     of    |
|-----+-----+-----+    Data   | Cylinders |
| Min | Avg | Max |   Blocks  |           |
+-----+-----+-----+-----------+-----------+
                              |           |
+-----+-----+-----+-----------+-----------+
|  39 |  74 | 112 |        25 |         4 |
|  11 |  11 |  11 |         2 |         2 |
|  17 |  18 |  19 |         2 |         2 |
|  39 |  74 | 112 |        25 |         6 |
|  11 |  11 |  11 |         2 |         2 |
|  17 |  18 |  19 |         2 |         2 |
+-----+-----+-----+-----------+-----------+

        ^^^^        ^^^^^^^^^^
        ||||        ||||||||||

multiply the AVG datablock size by the Total number of Datablocks.

so following the 1024 (primary data table) line accross we would get

      74 * 25 =  1850 sectors
      1850 sectors  * 512 bytes per sector = 947200 bytes.

you can do the same for the index subtables to get their sizes as well.



     
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