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Huge DB2 database size normal?


Max Mairle (1112) | asked Dec 15 '17, 5:11 a.m.
edited Dec 15 '17, 5:24 a.m.

Hi everyone,

we're currently setting up a Jazz server with all kinds of applications (RM, QM, CCM, AM, RELM, GC, DM). I installed it according to the installation instructions in version 6.0.4 a few weeks ago and also I followed the instructions on how to prepare the database since I’m completely new to DB2/Database administration.

This week I updated all applications to 6.0.5 since we had problems with DM and we wanted to try out DM 6.0.5 and the new Model Manager. For now only a few employees were gathering some requirements and testing if everything works as expected, so the database should still be pretty small.

Today I noticed that our databases are (in my opinion) ridiculously large:

---
/home/db2inst1/db2inst1/NODE0000
-------------------------------------------------------------------------
                         /..
    7.2 GiB [##########] /SQL00004
   
4.2 GiB [#####     ] /SQL00003

   
4.2 GiB [#####     ] /SQL00006

   
4.2 GiB [#####     ] /SQL00002

   
4.2 GiB [#####     ] /SQL00007

   
4.2 GiB [#####     ] /SQL00010

   
4.2 GiB [#####     ] /SQL00008

   
4.2 GiB [#####     ] /SQL00001

   
3.1 GiB [####      ] /SQL00009

 
352.1 MiB [          ] /LDX

 
320.1 MiB [          ] /RM

 
320.1 MiB [          ] /QM

 
256.2 MiB [          ] /CCM

 
256.1 MiB [          ] /DW

 
256.1 MiB [          ] /JTS

 
256.1 MiB [          ] /AM

 
256.1 MiB [          ] /RELM

 
256.1 MiB [          ] /GC

 
256.1 MiB [          ] /DM

 
54.6 MiB [          ] /SQL00005

  
40.0 KiB [          ] /sqldbdir



 

Database 1 entry:
Database name                        = RELM
 Local database directory             = /home/db2inst1
 
Database release level               = 14.00

Database 2 entry:
Database name                        = DW
 
Local database directory             = /home/db2inst1

 
Database release level               = 14.00

Database 3 entry:
Database name                        = LDX
 
Local database directory             = /home/db2inst1

 
Database release level               = 14.00

Database 4 entry:
Database name                        = QM
 
Local database directory             = /home/db2inst1

 
Database release level               = 14.00

Database 5 entry:
Database name                        = RM
 
Local database directory             = /home/db2inst1

 
Database release level               = 14.00

Database 6 entry:
 Database name                        = JTS
 
Local database directory             = /home/db2inst1

 
Database release level               = 14.00

Database 7 entry:
Database name                        = CCM
 
Local database directory             = /home/db2inst1

 
Database release level               = 14.00

Database 8 entry:
Database name                        = GC
 
Local database directory             = /home/db2inst1

 
Database release level               = 14.00

Database 9 entry:
Database name                        = AM
 
Local database directory             = /home/db2inst1

 
Database release level               = 14.00

Database 10 entry:
Database name                        = DM
 
Local database directory             = /home/db2inst1

 
Database release level               = 14.00

 

All databases have a huge jazzdata file which makes up for the majority of the size of the directory. “jazzdata” is also configured to be the “Data tablespace container” in our applications, so it seems like the Jazz server is storing a lot of data for some reason. On the other hand, If I make a snapshot of the whole system (it’s a VM) it can be compressed down to around 2,5 GB, so I guess the database is pretty empty despite its huge size?  We’re using DB2 11.1.2 fp2.

 

How can I figure out why the database is so huge and if the size is reasonable needed or just huge because of some faulty behavior? And if the size is only so huge by some faulty behavior, how could I fix that?

 

Let me know if you need some additional information.


Any help is much appreciated.


Best regards,

Max


Comments
Ralph Schoon commented Dec 15 '17, 7:16 a.m. | edited Dec 15 '17, 7:17 a.m.
FORUM ADMINISTRATOR / FORUM MODERATOR / JAZZ DEVELOPER

I am not a DBA and don't know usual sizes, however 2GB is no size at all for a database today. Note, my phone has 64GB storage already just as a guidance what big or small size is. 

I think the database also sets space up for organization etc. It is a database and stores data to enhance access speed and not to reduce size.

I think I remember that some host guys complained that the initial DB size is already 2 GB, and that is just as it is.


Max Mairle commented Dec 18 '17, 2:47 a.m.

Sure, 2GB is not much nowadays, but if it the databases alone add up to 42,3GB with only a few test artifacts in each application, I'm a bit concerned about the future size.

Having worked more with (also complex) webapplications and MySQL and the like everything more than a few megabytes for the database of a basically not yet used application seems huge to me.

Anyway, thanks for your answer, I'll try to keep an eye on the size of the databases.

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Kevin Ramer (4.5k8180199) | answered Dec 28 '17, 8:53 a.m.

If I recall, there is are entries in the conf/APP/teamserver.properties that indicate an initial number of pages for the storage for one of the tablespaces:

com.ibm.team.repository.db.db2.content.tablespace.numpages=250000

For a 16K page size as directed by the documentation on creating the databases that hits 4G right on the button.

250,000 * 16384 = 4,096,000,000


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