5 backup and system administration – Sybase ADAPTIVE SERVER IQ 12.4.0 User Manual

Page 34

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Using ISNULL() and COALESCE()

Adaptive Server IQ 12.4.0

34

Release Bulletin for Digital UNIX

The

NUMBER(*)

function is not supported and should be deleted from the

Adaptive Server IQ Reference Manual.

9.4.11 Using ISNULL() and COALESCE()

ISNULL() and COALESCE() can be used to convert NULL values into
something else. If these are used with an outer join, the production of this
expression gets pushed below the outer join. This behavior is acceptable on the
row-preserving side of the join, but on the side that NULLs are added to, it can
produce incorrect results. The ISNULL is processed in the vertical cursor, then
NULLs are added in the outer join.

9.5 Backup and system administration

9.5.1 New options for reserving space

Two new options let you control the amount of space reserved for adding more
disk space.

RESERVED_MAIN_DBSPACE_MB

Function

Controls the amount of space Adaptive Server IQ reserves for adding dbspaces
to the main IQ Store.

Allowed Values

Integer greater than zero, in megabytes

Default

1

Description

This option lets you control the amount of space Adaptive Server IQ sets aside
space in your main IQ Store, so that if you run out of disk space there you can
add a new dbspace.

Adaptive Server IQ sets aside 1 MB by default. This value is usually sufficient
to run the DDL commands.

You do not need to set aside room to hold the new dbspace. This option only
provides space for executing related DDL commands.

RESERVED_TEMP_DBSPACE_MB

Function

Controls the amount of space Adaptive Server IQ reserves for adding dbspaces
to the Temporary IQ Store.

Allowed Values

Integer greater than zero, in megabytes

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