Simple Tablespace
What is a Simple Tablespace?
A simple tablespace is a basic type of tablespace that stores tables and their data without complex features like partitioning or segmentation. It is one of the types of tablespaces available in DB2. However, it is less commonly used today due to limitations in flexibility and performance compared to newer tablespace types.
A simple tablespace is a basic storage container that holds tables and their data pages in a straightforward manner. Unlike other tablespace types, such as segmented or partitioned, a simple tablespace:
- Does not support advanced data organization (like segmentation or partitioning).
- Can store multiple tables within a single tablespace, which may lead to potential fragmentation over time.
- Has limited flexibility in managing storage, making it less ideal for large or complex applications.
Key Characteristics:
- Straightforward structure: Ideal for simple use cases without complex storage requirements.
- Shared storage: Multiple tables can be stored within a single simple tablespace, which may cause space management issues.
- Page-level locking: Supports page-level locking for data access control.
Creating a Simple Tablespace
To create a simple tablespace in DB2, we use the CREATE TABLESPACE
statement with the SIMPLE type (implicitly defined as the default when no segmentation or partitioning is specified).
Syntax -
Refer Table Space syntax for all the parameters and its meaning.
Examples - Creating a Simple Tablespace
CREATE TABLESPACE EMPLTSSM IN EMPLDB USING STOGROUP EMPLSG PRIQTY 500 SECQTY 100 BUFFERPOOL BP0 CLOSE YES;
- Creates a simple tablespace named
EMPLTSSM
within theEMPLDB
database. - Uses
EMPLSG
to allocate storage volumes. - Allocates
500 KB
of primary space and100 KB
of secondary space if more is needed. - Utilizes buffer pool
BP0
to optimize data access. - Sets the tablespace to close when not in use, freeing resources.
Altering a Simple Tablespace
To modify an existing simple tablespace, use the ALTER TABLESPACE
command.
We can adjust parameters like primary and secondary space allocations, change the buffer pool, or set the tablespace to open or close when not in use.
Examples - Altering a Simple Tablespace
ALTER TABLESPACE EMPLTSSM PRIQTY 600 SECQTY 150 BUFFERPOOL BP1 CLOSE NO;
- Increases primary space to
600 KB
. - Updates secondary space allocation to
150 KB
. - Changes buffer pool to
BP1
. - Keeps the tablespace open even when not in use.
Deleting a Simple Tablespace
To delete a simple tablespace, use the DROP TABLESPACE
statement.
This action removes the tablespace and any tables or indexes stored within it.
Examples - Deleting a Simple Tablespace
>DROP TABLESPACE EMPLTSSG;