IBM 000-8697 Benutzerhandbuch
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
the blob is finished. When the application tool process terminates the server
process, the buffers are also terminated.
the blob is finished. When the application tool process terminates the server
process, the buffers are also terminated.
illustrates the process of
creating a blobspace blob.
Figure 2-10
Data is written to a
blobspace without
passing through
shared memory.
shared memory.
Writing Data to a Blobspace:
1. Blobspace data flows from the pipe, through temporary buffers in the database server process
memory space, 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 to
memory space, 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 to
2. A record of the operation (insert, update, or delete) is written to the logical log buffer if the
database uses logging. (Refer to
database uses logging. (Refer to
OnLine
Shared
Memory
Shared
Memory
OnLine disk
Blobspace
Private
portion of
virtual
portion of
virtual
Pipe
1
2
Logical
log
buffer
Database server process
Temporary blob buffer
Application process
Temporary blob buffer