Large Datafile Sizes with Oracle 10g on ECC 6.0 SR3

[Former Member]

We installed ECC 6.0 SR3 on Oracle 10.2.0.2 and are wondering if the space usage is normal. We've allocated 125 GB for the partition, and the datafiles have the following sizes:

Sapdata1: 30.5 GB

Sapdata2: 26.2 GB

Sapdata3: 31.5 GB

Sapdata4: 28.6 GB

This leaves us with 7GB of free space on the database drive. 116GB of used space for the datafiles of a brand new SAP installation does not seem right. It doesnu2019t seem normal to me, coming from a MS SQL Server background where around 75 GB is sufficient.

Any feedback or assistance will be greatly appreciated....

[markus_doehr2]

> We installed ECC 6.0 SR3 on Oracle 10.2.0.2 and are wondering if the space usage is normal. We've allocated 125 GB for the partition, and the datafiles have the following sizes:

>

> Sapdata1: 30.5 GB

> Sapdata2: 26.2 GB

> Sapdata3: 31.5 GB

> Sapdata4: 28.6 GB

> This leaves us with 7GB of free space on the database drive. 116GB of used space for the datafiles of a brand new SAP installation does not seem right. It doesnu2019t seem normal to me, coming from a MS SQL Server background where around 75 GB is sufficient.

Oracle doesn't use the datafiles the same way SQL server does. If you e. g. drop a table from the database, the spaces is still occupied whereas on SQL server the allocated spaces is getting decreased automatically.

Oracle uses "Extents" to expand the space a table consumes, the size of that extent may be much more than actually necessary.

Those 116 GB are not filled completely, they are allocated on the filesystem.

Markus

[Former Member]

I understand the space has been allocated and not used completely, but DBACOCKPIT still shows 84% used.

[markus_doehr2]

What value do you look at?

There are several values listed there.

In "Space overview" you see the total size of the database and the filled size. In "Database - Overview" you see the "allocated size" and the amount what is really filled. Which size are you referring to?

Be aware that Oracle needs more space than other databases, this can be seen also in the size of the IDES systems, DB6, SQL + MaxDB need e. g. 100 GB for an SEM IDES whereas Oracle needs 130 GB.

Markus

[Former Member]

Sorry for not being clear

In space overview, under 'database' panel I see

Used: 84%

Total used: 25%

In database overview, under 'sizes' panel I see

Size: 117.07 GB

Used space: 98.35 GB (84%)

Free space: 18.72 GB (16%)

Per.Data: 98%

Per.Temp: 2%

In database overview, under substructures panel I see

Tablespaces: 7 Per.Table size: 25%

Segments: 160401 Per. Index size: 34%

Per. Other size: 41%

Edited by: Fahad Shafi on Jun 18, 2008 7:49 PM

[markus_doehr2]

Ok.

> Size: 117.07 GB

> Used space: 98.35 GB (84%)

> Free space: 18.72 GB (16%)

> Per.Data: 98%

> Per.Temp: 2%

The "used space" is the space, the database occupies - means, you have for Oracle 98 GB and for SQL-Server 75 GB.

The reason for this is due to the different tablespaces to store the different data, for each "class" you have some spare space left. On top come serveral other tablespaces (TEMP, UNDO) that do not exist as such in SQL-Server and are handled differently.

Markus

[Former Member]

Does this mean that for the 117 GB SAP's allocated for itself (out of the 125 GB available), the base install has already used up 84%? So by default it leaves itself only 18.72 GB to work with?

I was hoping the "Total used: 25%" was more reflective of its current space usage but I guess this is not the case?

[markus_doehr2]

The "total used" is the space that is allocated relative to the maximum growth of the database files. The database files are set to "autoextend" to a maximum size, that size is used to calculate that value.

It leaves 18 GB for working - true. This can be changed during the installation by selecting "expert options" where you can specify exactly who big the system is going to be (if you know that).

Markus

[markus_doehr2]

And before I forget - Check note 1028624 - Overview of DBA Cockpit for Oracle - and the attachment.

Markus