3-90 IBM Informix OnLine Database Server Administrator’s Guide
Create a Blobspace
Tocontinue the example, assume your OnLine page size is 2 KB. If you decide
on a 12-kilobyte blobpage size, specify the blobpage size parameter as 6. If
yourOnLine page size is 4 KB, specify the blobpage size parameter as 3. (That
is,the size of the blob rounded up to the nearest kilobyte, divided by the page
size, is equal to the blobpage size parameter.)
If a table has more than one blob column and the blobs are not close in size,
store the blobs in different blobspaces, each with an appropriately sized
blobpage.
A newly created blobspace is not immediately available for blob storage.
Blobspace logging and recovery require that the statement that creates a
blobspaceand the statements that insert blobs into that blobspace appear in
separate logical log files. This requirement is true for all blobspaces,
regardless of the logging status of the database.
To accommodate this requirement, executetbmode -l to switch to the next
logical log file after you create a blobspace.
From DB-Monitor
1. From withinDB-Monitor, select the Dbspaces menu, BLOBSpace
option to create a blobspace.
2. Enter the name of the new blobspace in theBLOBSpace Name field.
3. Ifyou want to create a mirror for the initial blobspace chunk, enter a
Y in the Mirror field. Otherwise, enterN.
4. Specify the blobpage size in theBLOBPage Size field.
5. Enter the complete pathname for the initial primary chunk of the
blobspacein the Full Pathnamefield of the primary chunk section.
6. Specify an offset in theOffset field if it is appropriate for your
device.
7. Enter the size of the chunk, in kilobytes, in theSize field.
8. If you are mirroring this blobspace, enter the mirror chunk full
pathname,size, and optional offset in the mirror chunk section of the
screen.