DBSPACETEMP

onconfig.std value

None

if not present

ROOTNAME

separators

Comma or colon (no white space)

range of values

The list of dbspaces can contain standard dbspaces, temporary dbspaces, or both. Use a colon or comma to separate the dbspaces in your list. The length of the list cannot exceed 254 characters.

takes effect

When the database server is shut down and restarted

environment variable
DBSPACETEMP

Specifies dbspaces that the database server uses to store temporary tables for a particular session. If DBSPACETEMP is not set, the default location is the root dbspace.

utilities

onspaces -t (See page Creating a Temporary Dbspace with the -t Option.)
onstat -d flags field (See page onstat -d.)

refer to

The following material:

• What is a temporary table, in the chapter on data storage in the IBM Informix Administrator's Guide
• IBM Informix Guide to SQL: Reference
• The order of precedence that the database server uses when it creates implicit sort files, in the IBM Informix Performance Guide
• The order of precedence of the default locations where the database server stores logged and unlogged temporary tables in the IBM Informix Guide to SQL: Reference.

DBSPACETEMP specifies a list of dbspaces that the database server uses to globally manage the storage of temporary tables. DBSPACETEMP improves performance by enabling the database server to spread out I/O for temporary tables efficiently across multiple disks. The database server also uses temporary dbspaces during backups to store the before-images of data that are overwritten while the backup is occurring.

DBSPACETEMP can contain dbspaces with a non-default page size, but all of the dbspaces in the DBSPACETEMP list must have the same page size. For more information about dbspaces in non-default buffer pools, see BUFFERPOOL.

If a client application needs to specify an alternative list of dbspaces to use for its temporary-table locations, the client can use the DBSPACETEMP environment variable to list them.

If both standard and temporary dbspaces are listed in the DBSPACETEMP configuration parameter or environment variable, the following rules apply:

• Sort, backup, implicit, and nonlogging explicit temporary tables are created in temporary dbspaces if adequate space exists.
• Explicit temporary tables created without the WITH NO LOG option are created in standard (rather than temporary) dbspaces.

When you create a temporary dbspace with ISA or with the onspaces utility, the database server does not use the newly created temporary dbspace until you perform the following steps.

If you use the DBSPACETEMP environment variable to create a temporary dbspace in a user session, the change takes effect immediately and overrides the DBSPACETEMP value in the ONCONFIG file.