MAIN_RESERVED_DBSPACE_MB option

Function

Controls the amount of space Sybase IQ reserves in the IQ main store.

Allowed values

Integer greater than or equal to 200, in megabytes

Default

200; Sybase IQ actually reserves a maximum of 50% and a minimum of 1% of the last read-write file in IQ_SYSTEM_MAIN

Scope

Can be set only for the PUBLIC group. Requires DBA permissions to set the option. Takes effect immediately. The server does not need to be restarted in order to change reserved space size.

Description

MAIN_RESERVED_DBSPACE_MB lets you control the amount of space Sybase IQ sets aside in your IQ main store for certain small but critical data structures used during release savepoint, commit, and checkpoint operations. For a production database, set this value to between 200MB and 1GB. The larger your IQ page size and number of concurrent connections, the more reserved space you need.

Reserved space size is calculated as a maximum of 50% and a minimum of 1% of the last read-write file in IQ_SYSTEM_MAIN.

See also

“IQ main store and IQ temporary store space management” in Chapter 5, “Working with Database Objects” in the System Administration Guide: Volume 1