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by James Overman
Commercial Systems Division Hewlett-Packard has implemented two more enhancements in Transact/iX (HP30138A.07.00).
They are: Expanded support of TurboIMAGE B-tree Ability to pass database and file ids to Transact/iX
Support of B-Trees in Transact | |
With the release of IMAGE/SQL that provided TurboIMAGE B-trees,
Transact/iX supported a portion of that feature. The Simple Argument
structure of DBFIND was supported requiring no modifications to the Transact
language. A FIND for X or U type items having B-tree indices and with
the BTREEMODE1 option ON performs index searching with a wildcard character. Here's
an example. First, assume the BTREEMODE1 option is set ON for this database. Also, B-tree indices have been created
for the key item of the master data set allowing for indexed retrievals.
See the TurboIMAGE Reference Manual if you
are not familiar with B-tree indexing. In Transact, the source code would look like the following: MOVE (NAME) = "Sm@";
SET(KEY) LIST(NAME);
OUTPUT(CHAIN) PEOPLE, LIST=(NAME); |
This program would display all names in the detail data set, PEOPLE, which begin with "Sm". The full capability of B-trees required more functionality
to be added to Transact/iX. HP has expanded upon the Simple Argument DBFIND by allowing other DBFIND modes to be specified. By allowing the DBFIND mode and the argument (structured or simple) to be specified,
Transact/iX supports the full capability of TurboIMAGE B-trees. The Structured Argument can be specified by the SET(KEY) and LIST(KEY) statements. The SET(KEY) sets both the argument and key registers to the search
argument item. The LIST(KEY) statement resets the key register to the search or key
item. The Structured Argument item can be constructed via parent/child
items or with simple items using string functions and concatenation. Transact/iX has an added FINDMODE option on DELETE, FIND, GET, OUTPUT, REPLACE, and PATH statements. The syntax looks like: FIND(CHAIN) dataset, LIST=(item1:item3), FINDMODE=4; |
The B-tree search can only be used for the following data
retrieval verbs: DELETE, FIND, GET, OUTPUT, REPLACE, and PATH. Only the CHAIN or RCHAIN modifiers can be used for the data retrieval verbs. The
key and argument register should be set prior to the data retrieval.
The STATUS count returned may not always be accurate. For example, DBFIND modes 21 and 24 do not return the correct chain count
or entry numbers. The complete syntax for the FIND verb is shown below. FIND [(modifier)] file-name [,option-list]; |
- Option-list
One or more of the following options, separated
by commas. Only the additional option is listed here. See the
Transact/iX Reference Manual for all the
other possible options. - FINDMODE=mode
Only available with the CHAIN or RCHAIN modifiers. Performs optimized searching of an index by
using TurboIMAGE/XL's B-tree index functionality or Third Party
Indexing. The mode is the mode that is specified for the DBFIND of this data retrieval verb.
If the FINDMODE option is not specified, DBFIND mode 1 is used.
Here are some examples of B-tree Structured Arguments in Transact/iX.
Assume BTREEMODE1 is ON and B-tree indices exist. system ex1,base=passks;
define(item) search-arg x(30):
search-type x(2)=search-arg(1):
search-version I(5,,2)=search-arg(3):
arg1-size I(5,,2)=search-arg(5):
arg2-size I(5,,2)=search-arg(7):
arg1 x(8)=search-arg(9):
arg2 x(8)=search-arg(17):
prod-no x(8):
ship-date x(6);
list search-arg,init:
prod-no:
ship-date;
<< Retrieve all product numbers beginning with PROD. >>
<< Uses DBFIND mode 1. >>
move (prod-no) = "PROD@";
set(key) list(prod-no);
output(chain) inventory, list=(prod-no:ship-date);
<< Retrieve all product numbers between PROD1 and PROD2. >>
<< Uses DBFIND mode 4. >>
<< Uses parent/child items to devise Structured Argument. >>
move (search-type) = "[]";
let (search-version) = 0;
let (arg1-size) = 8;
let (arg2-size) = 8;
move (arg1) = "PROD1 ";<< Blank pad the full number of characters.>>
move (arg2) = "PROD2 ";<< Blank pad the full number of characters.>>
set(key) list(search-arg);
list(key) prod-no;
output(chain) inventory, list=(prod-no:ship-date),findmode=4;
exit; system ex2, base=passks;
define(item) search-arg x(30):
search-version I(5,,2):
arg1-size I(5,,2):
arg2-size I(5,,2):
arg2 x(8):
prod-no x(8):
ship-date x(6);
list search-arg,init:
search-version,init: << 0 >>
arg1-size,init:
arg2-size,init:
arg2,init:
prod-no:
ship-date;
<< Use items and functions to concatenate the Structured Argument. >>
<< Use DBFIND mode 24. >>
<< Same output as the second part of Example 1. >>
<< search-version set to 0 during list statement >>
let (arg1-size) = 8;
let (arg2-size) = 8;
move (arg2) = "PROD2 "; << Blank pad. >>
move (search-arg) = "[]" + (search-version) + (arg1-size) +
(arg2-size) + col("PROD1",9) + col((arg2),17);
set(key) list(search-arg);
list(key) prod-no;
output(chain) inventory, list=(prod-no:ship-date),findmode=24;
<< Another way to setup the Structured Argument. >>
<< Same results as above. >>
list search-arg,init;
move (search-arg) = col("[]",1);
move (search-arg) = col((search-version),3);
move (search-arg) = col((arg1-size),5);
move (search-arg) = col((arg2-size),7);
move (search-arg) = col("PROD1",9);
move (search-arg) = col("PROD2",17);
set(key) list(search-arg);
list(key) prod-no;
output(chain) inventory, list=(prod-no:ship-date),findmode=24;
exit; File Open Transact | |
"File Open" is the name of the feature which allows database
and file ids to be passed into Transact/iX from other languages
or Third Party packages. This allows the Transact program to use
the same databases and files used by the calling program. The Ids
are shared so both programs can share current record numbers, entries,
paths, etc. This feature requires a call to TL_CALL_TRANSACT (aka Transact/iX ACI) from another language or package.
HP has also included an additional enhancement, the ability to defer
the database open. These enhancements required changes to two Transact/iX statements, SYSTEM and LIST. The SYSTEM statement needs to tell Transact/iX if the database or
file id is being passed. The new syntax is shown below.
SYSTEM program-name [,definition-list];
|
Definition-listDescription of the files or data sets used during
execution. See the Transact
Reference Manual for other definitions.
BASE=base-name[(["password"][,[mode][,[optlock][,[basetype][,[open-type]]]]])]. - open-type
Used by Transact/iX to determine when and if to
open the database. The valid types are OPEN, DEFER, PASSED. OPEN is the default and opens the database at the beginning
of the Transact/iX program. DEFER delays the database open until the database is first
accessed. PASSED tells Transact/iX not to open the database - the database id
is being passed from another program.
FILE=file-name[([access][(file-option-list)] [,[record-length] [,[blocking-factor] [,[file-size][,[extents] [,[initial-allocation][,[file-code]]]]]]])]. |
- file-option-list
Any of the following fields provided that they do
not conflict in meaning: OLD, NEW, TEMP, $STDLIST, $NEWPASS, $OLDPASS, $STDIN, $STDINX, $NULL, ASCII, CCTL, SHARE, LOCK, NOFILE, HP3000_16, HP3000_32, DEFER, PASSED. Either DEFER or PASSED can be specified. DEFER opens the file when the file is first used in a Transact/iX
program. PASSED does not open the file - generally the file id is passed
from another program. If neither DEFER or PASSED is specified, then DEFER is assumed. DEFER is the way Transact/iX worked prior to this enhancement.
KSAM= file-name[(access)[(file-option-list)]]. |
See FILE= for DEFER and PASSED options. The next statement that Transact/iX needed to enhance is the LIST statement. The new syntax is shown below.
LIST item-name[,option-list]; << Adds the item-name to the list >>
<< register.>>
|
Option-listSpecifies a value to be placed in the data register.
For current options, refer to the Transact Reference
Manual. - BASEID[(base-name)]
An X(2) item that contains the database id passed
from a main program assigned to a database by TurboIMAGE's DBOPEN. If no base-name is specified, then the home base is
assumed. Note, the home base cannot be specified. - FILEID(file-name)
A 16-bit integer (I(5,,2)) containing the file identifier assigned
to a file by MPE's FOPEN.
The database/file on the SYSTEM statement should have the PASSED option or an error will occur. Any database/file name
in the SYSTEM statement can actually be a different named database/file.
There is not a check to verify that the database/file names are
actually the same. For example, if the calling program opened a database named PEOPLE, then Transact/iX assigns that database id to its database
name of EMPLOYEES (structured the same as PEOPLE): LIST people-id,BASEID(employees); |
Example: Pascal Code - Main ProgramHere is an example using Pascal to call Transact/iX. .
.
.
type
data_record = packed record
x_type : packed array[1..8] of char;
id_type : packed array[1..2] of char;
filler : packed array[1..48] of char;
end;
.
.
.
var
data_buffer : data_record;
.
.
.
base_name := ' NAME; ';
password := 'PASS1 ';
mode := 1;
dbopen (base_name, password, mode, db_status_array);
{ check db_status_array }
.
.
.
strmove (2, base_name, 1, data_buffer.id_type, 1);
system_name := 'aci01 ';
data_size := 58;
tl_call_transact (system_name, addr(data_buffer),
data_size, return_status);
{ check Transact's return_status }
.
.
.
end. Example: Transact Code - Subprogram << This code is compiled and added to the XL. >>
system aci01,base=name(,1,,PASSED); << NAME database is not opened >>
<< by Transact/iX. >>
define(item) x-item x(8):
name-id x(2):
name x(8):
address x(32):
phone x(8);
list x-item:
name-id,BASEID: << Home base assumed. >>
name, init:
address,init:
phone,init;
<< Use database ID from Pascal code to perform retrieval. >>
output(serial) employees, list=(name:phone);
exit |
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