what is open data path? and what is the diff b/w access path
and open data path?
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Answer / mohan
An access path describes the order in which the rows are
retrieved from a database file. If the rows in the file are
accessed in a physical sequence, that is known as an
arrival sequence access path. If the rows need to be
processed in an ordered manner, then a keyed access path is
needed to sort the data in the specified order. With DB2
for iSeries, keyed access paths are supplied to DB2 by
creating a keyed logical file, keyed physical file, or SQL
index.
An access path and an open data path are used together to
process the rows in a database file.
The open data path (ODP) is the path through which all
input and output operations are performed on a database
file. The ODP is used to connect the requesting program
with the data in the file. As data is retrieved from or
inserted into the file, the ODP will use an access path to
navigate to a row within in the file. If the rows need to
be processed in a sorted owner, then someone will need to
supply a keyed access path by creating a keyed physical
file, keyed logical file or SQL index.
An ODP is created and used each time that a file is opened
or when an SQL statement is executed. There are ways to
have an ODP shared or reused instead of creating the ODP
each time.
Is This Answer Correct ? | 33 Yes | 1 No |
Answer / abhradeep chatterjee
An open data path is the path through which all
input/output operations
for the file are performed. In a sense, it connects the
program to a file. If you do not specify the SHARE(*YES)
parameter, a new open data path is created every time a
file is opened. If an active file is opened more than once
in the same job or activation group, you can use the active
ODP for the file with the current open of the file. You do
not have to create a new open data path.
Whereas, Access path is path through which you can retrieve
records. There are 6 types of access path is
supported by SYNON. By default Synon creates 3 access path
namely Physical, Update and
Retrieve access paths.
1. ‘PHY’: Physical file: Arrival sequence access path
defining the based-on file. For a given
AllFusion 2E file there may only be one access path of type
PHY - the path will automatically be
created by AllFusion 2E.
2. ‘UPD’: Update: Access path used for update. Path is
keyed on AllFusion 2E fields that identify
the file. For a given AllFusion 2E file there may be
several different access paths of type
UPD, each containing a different combination of fields. A
default update path containing all
fields will automatically be created by AllFusion 2E.
3. ‘RTV’: Retrieval: Access path used to retrieve records
from file. The key order cannot be
changed. For a given AllFusion 2E file there may be many
access path of type RTV - a default
path, keyed on the identifying fields for the file, will
automatically be created by AllFusion 2E.
Each ‘RTV’ access path has an associated 'UPD' access path.
4. ‘RSQ’: Resequence: Access path used to retrieve records
from file using an alternative key
order. For a given AllFusion 2E file there may be many
access paths of type 'RSQ'.
5. 'QRY' : Query: Access path used to retrieve records from
file using an alternative key
order which may include virtual fields. For a given
AllFusion 2E file there may be many
access paths of type 'QRY'.
6. ‘SPN’: Span: Access path used to span several different
files using an alternative key order.
For a given AllFusion 2E file there may be many access
paths of type 'SPN'.
Is This Answer Correct ? | 4 Yes | 0 No |
Answer / koti
thank u Mohan .I have doubht on this what is the perminent
ODP and temporary ODP ?
Is This Answer Correct ? | 2 Yes | 0 No |
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