Re: Listeners, Instances, Ports, ...

JRStern wrote:
>
> On Tue, 14 Apr 1998 16:16:00 GMT, chuckh_at_dvol.com (Chuck Hamilton)
> wrote:
> >They are logical containers of data (tables or indices). Logical
> >structures (tables and indices) reside in tablesapces. Tablespaces
in
> >turn are mapped to physical storage (i.e. datafiles) on the disk.
You
> >can have many tables or indices in a tablespace, and a tablespace
can
> >be comprised of one or many datafiles.
> >
> >
> >Locical mytable1 mytable2 myindex1
> > \ | /
> > +-----------------------+
> >Logical | Tablespace |
> > +-----------------------+
> > / \
> >Physical file1 file2
>
> Chuck,
>
> Thanks, that's clear, mostly. It's a second-level division of
> physical space. Apparently it does _not_ encapsulate the names of
> logical structures inside.
>
> Josh

In SQLServerland, you first create data files of fixed size ("devices"). When creating a database, you indicate which data files the database will straddle and allocate SOME PORTION of each of these data files to the database. You also create logical groupings of devices called "segments". Overlap IS PERMITTED in these groupings. Each table or index that you create lives entirely within the segment to which it is assigned. The maximum size of a table or index, therefore, is the total of the space allocated to the database in the data files listed in the segment definition.

In Oracleland, a database is made up of a set of "tablespaces", and each of these in turn is made up of a set of NON-SHARED data files of fixed size. Each table or index that you create lives entirely within the tablespace to which it is assigned. The maximum size of a table or index, therefore, is the total of the sizes of the data files comprising the tablespace.

Welcome to Oracleland. Beyond here there be dragons.

Cheers.
Ignatius.

• Views entirely my own. No warranties implied. ---