This parameter specifies the number of local databases
that can be concurrently active, or the maximum number of different
database aliases that can be cataloged on a DB2 Connect™ server.
This parameter is overloaded.
The effect of the
numdb database
manager configuration parameter depends on the environment in which
the parameter is used.
- For a DB2 Connect environment,
you can specify the maximum number of database aliases that can be
cataloged on a DB2 Connect server
using the numdb database manager configuration
parameter.
- Outside of a DB2 Connect environment,
you can specify the number of local databases that can be concurrently
active using the numdb database manager configuration
parameter.
- Configuration type
- Database manager
- Applies to
-
- Database server with local and remote clients
- Database server with only local clients
- Partitioned database server with local and remote clients
- Parameter type
- Configurable
- Default [range]
-
- UNIX DB2® pureScale® environment
- 32 [1 - 200]
- UNIX Database server with
local and remote clients
- 32 [1 - 256 ]
- UNIX Database server with
only local clients
- 8 [1 - 256 ]
- Windows Database server
with local and remote clients
- 32 [1 - 256 ]
- Windows Database
server with only local clients
- 3 [1 - 256 ]
- Unit of measure
- Counter
Usage notes
- It is important to remember when setting or updating this parameter
that each database takes up storage, and each active database requires
an additional new shared memory segment.
- Set numdb to the default value if the number
of databases being run on the instance is less than the default.
- Use of the numdb configuration parameter
must be coordinated with the db2_database_cf_memory and cf_db_mem_sz configuration
parameters.
- Changing the numdb parameter can impact the
total amount of memory allocated. As a result, frequent updates to
this parameter are not recommended. Plan the configurations for all
parameters that are related to memory allocation for a database or
an application connected to that database, and change them all at
the same time.
- In addition to the numdb limit
in a DB2 pureScale environment,
there is a maximum number of database activations across all members
in an instance. This maximum number is 512 database activations. As
an example, if each member in a four member DB2 pureScale environment
activated 200 databases, that is a total of 800 database member activations.
Since 800 database activations exceeds the maximum upper limit, an
error is returned.
- In a multiple database environment,
if member crash recovery (MCR) is required, the number of databases
that will be recovered in parallel on each member is set by the value
of the numdb configuration parameter or the DB2_MCR_RECOVERY_PARALLELISM_CAP registry
variable, whichever value is smaller.
DB2 10.5 for Linux, UNIX, and Windows