pctfree and pctused values -- results of a little test

From: Boivin, Patrice J <BoivinP_at_mar.dfo-mpo.gc.ca>
Date: Fri, 21 Jul 2000 10:38:38 -0300
Message-Id: <10565.112639@fatcity.com>

We did a little test to see the number of blocks used for different = pctfree
and pctused values.

There was little difference between pctfree 5, 10 and 15, but by = pctfree of
20 differences started to appear.

There is an anomaly in the results, though, I was curious if anyone = might be
able to explain this. Pctfree=3D10, pctused=3D45.

Row length for the data was 123, there are two varchar2 columns in the table, one of which is varchar2(300).

SEGMENT_NA BYTES BLOCKS EXTENTS INITIAL_EXTENT NEXT_EXTENT ---------- --------- --------- --------- -------------- -----------

F05U40         40960         5         4          16384        8192
F05U45         40960         5         4          16384        8192
F05U50         40960         5         4          16384        8192
F05U55         40960         5         4          16384        8192
F05U60         40960         5         4          16384        8192
F05U65         40960         5         4          16384        8192
F05U70         40960         5         4          16384        8192
F05U75         40960         5         4          16384        8192
F05U80         40960         5         4          16384        8192
F05U85         40960         5         4          16384        8192
F05U90         40960         5         4          16384        8192
F05U95         40960         5         4          16384        8192
F10U40         40960         5         4          16384        8192
F10U45         73728         9         3          16384        8192
F10U50         40960         5         4          16384        8192
F10U55         40960         5         4          16384        8192
F10U60         40960         5         4          16384        8192
F10U65         40960         5         4          16384        8192
F10U70         40960         5         4          16384        8192
F10U75         40960         5         4          16384        8192
F10U80         40960         5         4          16384        8192
F10U85         40960         5         4          16384        8192
F10U90         40960         5         4          16384        8192
F20U40         49152         6         5          16384        8192
F30U40         49152         6         5          16384        8192
F70U30        106496        13        12          16384        8192

Block size is 8192, initial and next were set to 8K to really see if = there
would be a difference in allocated blocks.

We also tested for pctfree 15 pctused 40, there was no difference = between
pctfree 10 and pctfree 15.

TIA
Patrice Boivin
Systems Analyst (Oracle Certified DBA)

Systems Admin & Operations | Admin. et Exploit. des syst=E8mes
Technology Services        | Services technologiques
Informatics Branch         | Direction de l'informatique=20
Maritimes Region, DFO      | R=E9gion des Maritimes, MPO

E-Mail: boivinp_at_mar.dfo-mpo.gc.ca <mailto:boivinp_at_mar.dfo-mpo.gc.ca>=20 Received on Fri Jul 21 2000 - 08:38:38 CDT