| When you logon to any db2 database server the first | | | | settings are defined in the database configuration file. |
| thing you have to look for is the number of instances | | | | Main storage objects in the db2 environment are the |
| on the box. Db2ilist utility can be used to know about | | | | tablespaces. Tablespace can have one or many |
| the instances present in the box. Once the instances | | | | containers. Containers are the physical devices that |
| are identified one has to attach to the instance of his | | | | contain the data. Tablespaces can be SMS type or |
| liking. Attach command can be used to attach to the | | | | DMS type. SMS type are the system managed space |
| instance. After attaching to the instance, database | | | | tablespaces which are managed completely by |
| directory can be used to list all the databases in the | | | | database manager. Once the tablespace is defined, |
| instance. An instance can accommodate one or many | | | | the expansion of it is completely handled by the |
| databases. So it all depends on the memory available | | | | database manager. For DMS tablespaces you have to |
| on the box to accommodate the databases here. | | | | allocate the needed space upfront and the expansion |
| Instance level configuration dictates the memory heap | | | | has to be taken care by the DBA. At the minimum one |
| limits like fenced pool parameters, agent level | | | | container is needed for a tablespace. But generally it is |
| parameters etc. Registry variables are the | | | | recommended that there are three containers per |
| configuration settings that apply for all the instances on | | | | tablespace for parallel i/o which might improve the |
| the box. You can use the global setting to apply the | | | | overall performance of the application. |
| registry change to all the instances. Individual database | | | | |