IBM 000-8697 Manual Do Utilizador

IBM Informix OnLine Database Server Administrator’s Guide

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Physical log

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Shared-memory parameters

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Configuration issues that affect the logical logs and archiving are described
in the sections beginning on

 and

, respectively. Infor-

mation and guidelines for setting the value of shared-memory parameters
are provided in

 Infor-

mation about performance tuning is provided in

Use a blobspace to store large volumes of

 BYTE

 and

TEXT

 data types. Blobs

stored in a blobspace are written directly to disk. The blob data does not pass
through the shared-memory buffer pool. If it did, the volumes of data could
occupy so many of the buffer-pool pages that other data and index pages
would be forced out.

For the same reason, blobs stored in a blobspace are not written to either the
logical or physical log. The blobspace blobs are logged by writing the blobs
directly from disk to the logical log backup tapes, without ever passing
through the logical log files.

Refer to

 for further information about writing a blob directly to

disk. Refer to

 for further information about blobspace logging.