What file drivers does the
IPDS support?
You can
use any Clarion file driver (ODBC, MS-Sql, Btrieve, Clarion, TopSpeed, Ascii,
etc). The
Dynamic File driver template also supports caching to In-Memory tables or to
physical tables, so you can work with offline tables and detached
recordsets.
Does the Dyna driver work with both ABC and Clarion
template chains?
Yes
absolutely, there are examples shipped that demonstrate integration into Apps
using both Template chains, and in hand-coded programs too.
What benefits does it bring to my
applications?
Many benefits, but for instance one of the shipping examples demonstrates
the effect of local-caching on a report. The example contains 2 report
procedures, one cached - one not. The cached report is around 80% faster then
the uncached one. In other words the Report using local caching is 5 times
faster than the original one. The report is completely unchanged, except for the
addition of the Dyna Driver extension template. This technique will also work
regardless of the report template used, or if the report is hand-coded.
How long does it take to enable an application to use
the Dyna Driver?
In
general you only need to add the extension template to each .App file that
comprises your application and fill in the prompts, be sure to look at the
reference manual for a good explanation of how to work with the driver and
templates.
Can I distribute the Dyna driver
royalty-free?
Yes, as
with all Clarion products there are no royalties on distribution.
Does the DFD support Groups, BLOBs and Memo
fields?
Yes, all data types are supported.
What are the advantages of caching result
sets?
The
caching technique should be particularly effective for SQL users as it reduces
the number of SQL instructions (to a single sequential read-pass through the
table) - after that individual lookups are done on the client computer.
With
both ISAM and SQL this technique has a dual benefit. Not only is the action on
this client faster, but the load on the server is dramatically reduced, thus
speeding up the server for all other users as well. The speed improvement is
proportional to the speed of the data connection. The slower the connection
currently, the more dramatic the speed improvement.
Can I use Prop:SQL and stored procedures to create Dyna
Files?
Yes, the
Dyna Driver has special functionality that allows you to create a new Dynamic
File structure from an SQL result set. Any SQL that returns results like SELECT
or a Stored Procedure can be used to create a File structure that matches the
columns (fields) returned, and the Dyna Class can create a file and fill it with
records with just a few lines of code, for example:
MSProducts &= NEW(DynFile)
MEMProducts &=
NEW(DynFile)
MSProducts.SetDriver('MSSQL')
!MSProducts.SetOwner('(local),Northwind,sa,sa2000')
MSProducts.SetOwner('(local),Northwind,sa,')
MSProducts.CreateFromSQL('SELECT
ProductID, ProductName FROM Products')
creates a new Dynamic File with the two fields (ProductID and
ProductName).
MEMProducts.SetCreate(true)
MEMProducts.SetName('MEMProduct')
MEMProducts.SetDriver('MEMORY')
MEMProducts.FillFrom(MSProducts)
and just a few more lines of code will cache the result set into a local
table -- in this code we used an In-Memory table but we could have just as
easily used a TopSpeed table, or any other driver.
Better
yet, the Dyna Driver template will write all of the code for you.
More
questions? We
suggest that you download and review the Dynamic File Driver Reference manual
