TurboIMAGE/XL Database Management System Reference Manual MPE/iX V6.5 (30391-90011)
502 Chapter11
B-Tree Indices
External Commands and Utilities Affected
TPI Modes of DBFIND Not Supported for B-Tree Indices
Third-Party Indexing (TPI) adds more DBFIND modes. The TPI modes 1 and 10 are similar
to B-Tree index modes 1 and 10.
NOTE
These are the known Third Party Indexing (TPI) modes of DBFIND which are
NOT supported for B-Tree searches:
11 do a B-Tree index DBFIND when the key is binary.
12 is a keyword search.
other 1nn, 2nn, 3nn, 4nn, and 5nn are other unsupported TPI DBFIND modes.
A B-Tree index search will never be done with a DBFIND mode 1 style argument if the key
item is binary (not X or U) (this affects DBFIND modes 1 and 21). For a B-Tree index search
on binary (non-ASCII) data, use modes 4 or 24 in conjunction with a structured argument.
A DBFIND mode 21 on a non-ASCII item returns an error.
All TurboIMAGE data types are allowed as keys for B-Tree searches.
DBFIND Modes
Following is a DBFIND mode summary table (see footnotes for explanations):
Table 11-1. DBFIND Mode Summary Chart
DBFIND\Mode B-Tree index \search? Accurate\Chain
counts?
Argument\style
1
MAYBE
a
a. If BTREEMODE1 is ON, a DBFIND mode 1 on an ASCII item with a B-Tree index (explicit or
implicit), and mode 1 style argument contains a wildcard character, it will be treated as a
B-Tree index search. If BTREEMODE1 is OFF, a DBFIND mode 1 in the above scenario will be
treated as a non-B-Tree index search (as if there were no B-Tree index feature). DBFIND
mode 1 on binary items (not X and U) will be treated as non-B-Tree search regardless of
the presence of a B-Tree index as well as the BTREEMODE1 option. To do B-Tree searches
on binary items, use modes 4 or 24 in conjunction with a structured argument.
YES
b
or YES
c
b. The chain count is the number of entries in the single chain (non-B-Tree DBFIND). Record
number for the last entry and first entry is obtained from the chain head.
mode 1
d
4 YES
YES
c
mode 4
e
10 NO
YES
b
mode 1
d
21
YES
f
NO
g
mode 1
d
24 YES
NO
g
mode 4
e