Communicator 3000 MPE/iX Release 6.0 (Platform Software Release C.60.00) (30216-90269)
164 Chapter 10
Technical Articles
IMAGE/SQL with TurboIMAGE/XL Enhancements
10 allows you to simulate DBFIND mode 1 as if there
were no B-Tree index. This is the same as TPI mode
10. Requires the classic mode 1 argument format.
21 is the same as B-Tree index search using DBFIND
mode 1, except it is a faster version and does not
return accurate chain counts. Requires the classic
mode 1 argument format.
24 is the same as B-Tree index search using DBFIND
mode 4, except it is a faster version and does not
return accurate chain counts. Requires a new
structured argument.
Allows wildcard search, as well as range search (<, <=, >,
>=,"PK" for partial key, or [] for between).
9. DBGET modes 5 and 6 can be used for B-Tree index retrieval for
masters or details. Super-chains are traversed for detail data sets.
10.KSAM/iX files are used for B-Tree index files. These are KSAM
related key points:
• There is one KSAM/iX privileged file with a filecode of -412 for
each B-Tree index file. The size limit for this B-Tree index file is 4
GB. A jumbo master (larger than 4 GB) can have a B-Tree index
file provided the B-Tree index file remains within its 4 GB limit.
• KSAM/iX B-Tree index file is named using the POSIX file format
with the “idx” extension (lowercase). For example:
/ACTSALES/GRPSALES/ORDERS03.idx
• The KSAM file has the Native Language Support language
specified to match the language of the database, if the key is an
ASCII type.
11.Third-party index can coexist with B-Tree index, that is, on the same
item of the data set.
Quick Start for Using B-Tree Indices
If you are interested in generic trailing-@ searches only and want to get
started quickly without making any application changes, you may use
the following steps.
1. Identify the masters with ASCII key item that can benefit from
B-Tree indices.
2. Create B-Tree indices using either of these methods:
a. Use the INDEXED option of DBSCHEMA for new databases.
b. Use the ADDINDEX command of DBUTIL for existing databases.
3. Set the BTREEMODE1 option ON using DBUTIL as follows: