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IRIX Installation Tools & Overlays 2001 November
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SGI IRIX Installation Tools & Overlays 2001 November - Disc 3.iso
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relnotes
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dba
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ch4.z
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2001-10-10
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133 lines
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4. _S_p_e_c_i_a_l__N_o_t_e_s__o_n__U_s_e__o_f__T_h_i_s__P_r_o_d_u_c_t
The database accelerator (DBA) is designed to speed up your
Oracle, Informix, or Sybase database server. In some cases
your database server has been specially coded to take
advantage of features in the database accelerator (such as
the postwait driver for all versions of Oracle, and the
special async I/O support in Oracle version 7). You will
need to install this software and refer to your platform-
specific database server documentation to find out how to
make your server take advantage of DBA.
Kernel asynchronous I/O (sometimes referred to as KAIO) is
designed to work invisibly with an application that uses
POSIX asynchronous I/O but follows certain strict
conditions. Silicon Graphics and the database server
companies work together to make sure those conditions are
always met.
However, DBA 3.0 for IRIX 6.5 is incompatible with some
older versions of the Informix database server. Please
contact Informix Corp. for more information. The symptom of
the problem is that the Informix server will hang after
several thousand disk I/O requests have been submitted.
If you are running Informix, you should not install this
product unless your documentation specifically states that
your version of Informix will work with DBA on IRIX 6.5.
4.1 _E_n_a_b_l_i_n_g__K_A_I_O
Some database servers are aware of the presence or absence
of KAIO on IRIX and can automatically take advantage of it
if present. For these servers, you will not need to do
anything.
Other servers may require you to set a configuration
variable to take advantage of KAIO. You will need to consult
your database server documentation (probably the IRIX-
specific release notes) or contact your database company's
support organization to find out if there is such a
variable.
An others, particularly older versions, are unaware of KAIO
and do not have a way for the database server to enable it
itself. You can force KAIO on for these database servers by
setting an environment variable before starting your server.
You may also need to set the environment variable for
application processes as well (for example, a TWO_TASK
Oracle application). To forcibly enable KAIO:
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1. In csh or tcsh, type
sssseeeetttteeeennnnvvvv ________SSSSGGGGIIII____UUUUSSSSEEEE____DDDDBBBBAAAA 1111
2. In sh or ksh or bash, type
eeeexxxxppppoooorrrrtttt ________SSSSGGGGIIII____UUUUSSSSEEEE____DDDDBBBBAAAA;;;; ________SSSSGGGGIIII____UUUUSSSSEEEE____DDDDBBBBAAAA====1111
In some cases, your database server company may inform you
that use of certain features in the IRIX database
accelerator is unsupported.