How do you determine the size of a table?

[xsw1971]

I have always used default storage parameters when building Oracle tables, but I was wondering if someone could explain how to determine the amount of storage space that should be allocated when building a table (that is, if I don't want to accept the default.)

I have tried reading about it and following the steps in Oracle Press books, but it's so cryptic I can't follow it.

Thanks in advance!
Jen

 

[RaymonG]

All depends on the data you want to put into the table. The amount is important, but also the size of the data itself. Normally I use the following syntax:

STORAGE ( INITIAL 100K
NEXT 10K
MINEXTENTS 5
MAXEXTENTS UNLIMITED
PCTINCREASE 0 );

This means that my first extent will be 100K (max 4095M, min 4K), when this extent is full it will add another 10K to it (NEXT). MINEXTENTS provides the total of extents created at first. MAXEXTENTS is the number of extents maximum created. Unlimited means, ofcourse, there is no limit. If you have a disk-size problem, be carefull with this. PCTINCREASE provides the percentage of growth of the NEXT extent. If PCTINCREASE > 0 then NEXT will be NEXT * (1 + PCTINCREASE/100) in Kb. You also have an option FREELISTS. The maximum value of this parameter depends on the size of the datablock. The benefit of FREELISTS is the speed when several users are adding data.

Hope this will help you out a little.

Raymon

 

[xsw1971]

Thanks for the reply Raymon,

That was helpful, although still a little confusing. My DBA told me that whatever I set for INITIAL is up to me, but that should always make NEXT the same value as INITIAL. Does that make sense to you?

Thanks!
Jen

 

[RaymonG]

JennieM, well, it is not necessary in my opinion, but I guess we all have our own ideas about parameters