IBM 000-8697 - page 174

2-80 IBM Informix OnLine Database Server Administrator’s Guide
Writing Data to a Blobspace
The blobspace buffers remain until the OnLine server process that opened
theblob is finished. When the application tool process terminates the server
process,the buffers are also terminated. Figure 2-10 illustrates the process of
creating a blobspaceblob.
Figure2-10
Data is written to a
blobspace without
passing through
shared memory.
Writing Data to a Blobspace:
1.Blobspace data flows from the pipe, through temporary buffers in the database server process
memoryspace, and is written directly to disk. Blobspace blobpages are allocated and tracked via
the free-map page. Links connecting the blobpages and pointers to the next blob segments are
created as needed. (Refer topage 2-147.)
2. A record of the operation (insert, update, or delete) is written to the logical log buffer if the
database useslogging. (Refer to page4-22 for more information about blobspace logging.)
OnLine
Shared
Memory OnLine disk
Blobspace
Private
portion of
virtual
Pipe
1
2
Logical
log
buffer
Database server process
Temporary blob buffer
Application process
Temporary blob buffer