Re: Oracle10g/11g, scrollable cursors, and JDBC scrollable result

#1

Comments embedded.

On Sep 30, 6:51*pm, jms <jesus.m.sa... (AT) gmail (DOT) com> wrote:

Quote:

According to the following documents from Oracle's JDBC drivers for
10g and 11g:

http://download.oracle.com/docs/cd/B...14355/resltset...

http://download.oracle.com/docs/cd/B...31224/resltset...

To quote:

"Oracle JDBC Implementation for Result Set Scrollability

Because the underlying server does not support scrollable cursors,
Oracle JDBC must implement scrollability in a separate layer.

It is important to be aware that this is accomplished by using a
client-side memory cache to store rows of a scrollable result set.

Important:
Because all rows of any scrollable result set are stored in the client-
side cache, a situation where the result set contains many rows, many
columns, or very large columns might cause the client-side Java
virtual machine (JVM) to fail. Do not specify scrollability for a
large result set."

But Oracle's own documentation for the database server itself says
that it does support scrollable cursors:

http://download.oracle.com/docs/cd/B.../b14220/sqlpls...

So the question is ... what does Oracle's JDBC thin driver actually
do ??

Implements JDBC 2.0 result set functionality.

Quote:

Does it use a scrollable cursor or not ?

It does what the documentation which you posted states:

"Because the underlying server does not support scrollable cursors,
Oracle JDBC must implement scrollability in a separate layer.

It is important to be aware that this is accomplished by using a
client-side memory cache to store rows of a scrollable result set."

The links to the java implementation provide examples of java-style
scrollable cursors. The commands to manipulate those differ greatly
from those available in OCI/OCCI.

Quote:

If not, which one does ?

The scrollable cursors you refer to, mentioned in the last link
provided by your post, are an OCI/OCCI implementation, which is an
entirely different programming interface. Visit that link again and
you'll see, down the page, an example of an OCI scrollable cursor.

Quote:

John

David Fitzjarrell

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Re: Oracle10g/11g, scrollable cursors, and JDBC scrollable result

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Re: Oracle10g/11g, scrollable cursors, and JDBC scrollable result - 10-01-2008 , 10:11 AM