MAX_TEMP_SPACE_PER_CONNECTION Option

Limits temporary store space used per connection.

Allowed Values

Integer (number of MB)

Default

0 (no limit on temporary store usage)

Scope

DBA permissions are required to set this option. Can be set temporary for an individual connection or for the PUBLIC group. Takes effect immediately.

Description

By controlling space per connection, this option enables DBAs to manage the space for both loads and queries. If the connection exceeds the run time quota specified by MAX_TEMP_SPACE_PER_CONNECTION, Sybase IQ rolls back the current statement and returns this message to the IQ message file or client user:

The current operation has been cancelled: Max_Temp_Space_Per_Connection exceeded

Conditions that may fill the buffer cache include read or write errors, lack of main or temp space, or being out of memory. Sybase IQ may return the first error encountered in these situations and the DBA must determine the appropriate solution. For more information, see Error Messages and System Administration Guide: Volume 1 > Troubleshooting Hints.

In a distributed query processing transaction, Sybase IQ uses the values set for the QUERY_TEMP_SPACE_LIMIT and MAX_TEMP_SPACE_PER_CONNECTION options for the shared temporary store by limiting the total shared and local temporary space used by all nodes participating in the distributed query. This means that any single query cannot exceed the total temporary space limit (from IQ_SYSTEM_TEMP and IQ_SHARED_TEMP dbspaces), no matter how many nodes participate.

For example, if the limit is 100 and four nodes use 25 units of temporary space each, the query is within limits. If the sum of the total space used by any of the nodes exceeds 100, however, the query rolls back.

Examples

Set a 500GB limit for all connections:

SET OPTION 
PUBLIC.MAX_TEMP_SPACE_PER_CONNECTION = 512000

Set a 10TB limit for all connections:

SET OPTION 
PUBLIC.MAX_TEMP_SPACE_PER_CONNECTION = 10485760

Set a 5000MB limit for user wilson:

SET OPTION 
wilson.MAX_TEMP_SPACE_PER_CONNECTION = 5000
Related reference
QUERY_TEMP_SPACE_LIMIT Option