Communicator 3000 MPE/iX Release 6.0 (Platform Software Release C.60.00) (30216-90269)

168 Chapter 10
Technical Articles
IMAGE/SQL with TurboIMAGE/XL Enhancements
Based on the above formula for calculating MPE records, the initial
capacity was 1 MPE record ( (10+9)/10), and the increment was 50
MPE records ( (500+9)/10). The correct physical EOF should be 51
(1+50). However, IMAGE EOF as shown by QUERY is 101
(1+50+50). This establishes that the IMAGE EOF was adjusted
twice.
If you use one of the IMAGE/SQL structure maintenance tools (such as
Adager, DBCPLUS, or DBGENERAL), it may have the capability to locate
instances of this problem, and if you discover that one of your data sets
is so afflicted, it may be possible to correct the problem using the same
tool. (See the documentation for your tool.)
How to avoid experiencing this problem on your IMAGE
database. The simplest answer is to install and use the
TurboIMAGE/XL patch mentioned above. This is the option that HP
recommends.
However, if you are unable to acquire and install the patch immediately,
consider the following alternative:
• Until you install the patch, avoid opening a data set from one
process while another is expanding it!
Here are some ways you might accomplish this; each way is
independent of the others:
1. Preallocate and pre-expand DDX data sets which are nearly-full by
adding, in exclusive mode, many new dummy entries. Add more than
your actual processing will add. Then delete them before your real
processing begins.
2. Open all DDX-enabled data sets needed from each process which
accesses them before allowing any process to add data to any of these
sets.
3. Access the database exclusively, if possible, until the expansion has
completed.
4. Disable DDX on any nearly-full data set, using an HP or third-party
tool.