spool vs free cylinder in Ferret show space output

Database
Enthusiast

spool vs free cylinder in Ferret show space output

This is output of Ferre’s show space:

                                +----------------+                                +----------------+                +-----------+

                                | Perm Data Cyls |                           |   Spool Cyls   |                 | Free Cyls |

                                 +----------------+                               +----------------+                +-----------+

                                |Avg  % of       |                                  |Avg  % of       |                  |% of       |

                         Tota|utl  total      |                                     |utl  total      |                     |total      |

Proc                  Avail|per  Avail      |                                   |per  Avail      |                   |Avail      |

Num              Cyls|Cyl  Cyls   #Cyl|                               |Cyl  Cyls   #Cyl|                |Cyls   #Cyl|

                                +----------------+                                +----------------+                +-----------+

0               102852 | 86%  81%  82821|                           | 92%   2%   1714|             | 18%  18258|

                               +----------------+                                 +----------------+                +-----------+

1              102852 | 87%  80%  82573|                           | 92%   2%   1729|             | 18%  18484|

                                 +----------------+                               +----------------+                +-----------+

2              102852 | 87%  80%  82464|                           | 92%   2%   1713|             | 18%  18606|

I’ve noticed that:

Total available cylinder = # perm data cylinder  + # spool cylinder + # free cylinder

My misconception :

  1. I though all system’s free space is available for spool, as we have a database dedicated to spool hold most of unused space in the system and by any means not 18% of cylinder is free, Hence this free space includes the spool space also , Correct ??

If 1 is correct .

  1. Why spool cyls is not computed as part of free cylinders and also what’s the meaning of the $ total avail. Cyls under “SPOOL” columns = 2%; while we do have 18% of free space which can be used as a spool.

2 REPLIES
Junior Contributor

Re: spool vs free cylinder in Ferret show space output

A cylinder is used for spool OR temp OR perm OR Journal, but they are not pre-assigned.

Whenever a new cylinder is needed it's taken from the FREE cylinders and when it's released it's added back to FREE again.

According to your ferret output there's currently 2% of the cylinders assigned to spool, but the remaining 18% could also be spool if needed. If there are some huge queries running the number of spool cylinders will grow and when they are finished it will shrink again.

Dieter

Enthusiast

Re: spool vs free cylinder in Ferret show space output

Hi Dieter,

What are the crietria that we propose that these many cylinders are needed say for extreme data appliance or DW appliance? Upto what extent cylinders can strecth to support spool, perm, temp and journal?

Thanks and regards,

Raja