Re: Delphi's native access to Oracle

vera_at_mda.ca (Felipe Vera) wrote:
>
>I'm confused about what Borland means when they say Delphi provides
>"native access" to Oracle.
>
>Does this mean that the Oracle Call Interface (OCI) is directly
>available at a programmatic level? Or is some subset of OCI available
>through Borland's Integrated Database API (IDAPI)? Most importantly,
>how much of the OCI functionality is available directly from Delphi's
>database controls?
>
>Finally, could someone describe the default transaction model provided
>by Delphi's database controls?

The native links are optimized high performance, non-ODBC links. I'm not an Oracle user so I don't know about OCI support. The following is extracted from th online help for a TDataBase component:

TDataBase component

The TransIsolation property specifies the transaction isolation level used by an SQL server. tiDirtyRead causes any change to be returned, regardless of whether the record has been committed. tiReadCommitted will return only committed versions of the record; uncommitted changes will not be reflected in the result. tiRepeatableRead will return only the original record for the duration of the transaction, even if another application has committed a change. Database servers may support these isolation levels differently or not at all. If the requested isolation level is not supported by the server, then Delphi will use the next highest isolation level, as shown in the following table. For a detailed description of how each isolation level is implemented, see your server documentation.

TransIsolation setting Oracle Sybase and Microsoft SQL servers InformixInterBase

Dirty read	Read committed	Read committed	Dirty Read	Read committed
Read committed	(Default)	Read committed	Read committed	Read committedRead committed
Repeatable read	Repeatable read (READ ONLY) 	Read committed	Repeatable Read	Repeatable Read

Michael Lant
SDSI Toronto Canada Received on Fri Dec 29 1995 - 00:00:00 CET