Manage Data Storage

Specify how SAP Sybase IQ allocates disk space and make sure that data is organized on disk for optimal performance.

• Space Allocation
  All SAP Sybase IQ databases are preallocated, whether they reside in a file system or a raw partition.
• Types of Dbspaces
  Each type of dbspace stores a particular type of SAP Sybase IQ data.
• Space for Databases
  The first dbspace for each store is created automatically when you create the database. You can create additional dbspaces as needed.
• Space Requirements for IQ Stores and Temporary Stores
  The amount of data, and the number and types of indexes you create, determine how much space you need in your database.
• Sizing Guidelines for Main and Temporary Stores
  The SAP Sybase IQ architecture influences guidelines for data storage.
• Setting Up Windows Access to Raw Devices
  Windows systems restrict raw device access to user accounts with Administrator privilege.
• Viewing Access Permissions of a RAW Device
  Display the current access permissions of a Windows RAW device.
• Setting Permissions to a RAW Device
  Set access permissions to a RAW device on Windows is required before you can use it.
• Setting Up Symbolic Links for Raw Devices on Windows
  Symbolic links simplify raw device access on Windows systems and persist across reboots.
• Estimating Space and Dbspaces Required
  To avoid difficulties when a database or a particular dbspace is full, estimate dbspace requirements before you create the database and the objects in it.
• Dbspace Management Example
  This section illustrates the dbspace management process from creating a new database and adding objects and data to the database, through relocating objects and dropping the empty dbspace. This example includes sample SQL code and the output of the related system stored procedures.
• Data Storage
  A DBA can determine which tables and indexes reside on a given dbspace, relocate objects to other dbspaces, and drop any dbspace after emptying it of data.
• Cache Dbspace for Direct-Attached Storage
  Add direct-attached storage devices, such as solid-state disks (SSDs), to a multiplex node or a simplex server by configuring a cache dbspace local to each node. Local direct-attached storage provides an SSD buffer pool extension to your database, which can improve I/O performance in general, and shared SAN device performance in particular. Although multiplex configurations gain the most benefit from direct-attached storage, simplex servers can benefit too.