Bug 837216

Summary:	REST api raw export as JSON fails for Oracle backend
Product:	[Other] RHQ Project	Reporter:	Heiko W. Rupp <hrupp>
Component:	Core Server	Assignee:	Heiko W. Rupp <hrupp>
Status:	CLOSED CURRENTRELEASE	QA Contact:	Mike Foley <mfoley>
Severity:	unspecified	Docs Contact:
Priority:	unspecified
Version:	4.4	CC:	ccrouch, hrupp
Target Milestone:	---
Target Release:	RHQ 4.5.0
Hardware:	Unspecified
OS:	Unspecified
Whiteboard:
Fixed In Version:		Doc Type:	Bug Fix
Doc Text:		Story Points:	---
Clone Of:
Clones:	844407 (view as bug list)		Environment:
Last Closed:	2013-09-01 10:10:33 UTC	Type:	Bug
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:
Bug Depends On:
Bug Blocks:	844407

Description Heiko W. Rupp 2012-07-03 07:42:17 UTC

For Oracle databases exporting raw metrics fails because of 

if (!rs.isLast()) in 
org.rhq.enterprise.server.rest.MetricHandlerBean.RawNumericStreamingOutput#write
as Oracle needs a special open mode for this cursor to use.

A working solution is changing
ps = connection.prepareStatement( sb.toString() );
to be
ps = connection.prepareStatement( sb.toString(), 
ResultSet.TYPE_SCROLL_INSENSITIVE, ResultSet.CONCUR_READ_ONLY );

It is not yet clear though if that has any performance impact and if there is a 
better solution.

We could run a count-query first and then loop, but effectively this means 
double work on the database too.

Comment 1 Heiko W. Rupp 2012-07-03 07:47:56 UTC

One could probably defer writing the ',' to the start of the inner loop when 
rs.next() is true.

boolean needsComma = false;
while (rs.next()) {
   if (needsComma) 
          pw.write(",");
   needsComma = true;
   pw.write("{");
   ...
}

Comment 2 Heiko W. Rupp 2012-07-03 10:55:30 UTC

master bbf48d7

Comment 3 Heiko W. Rupp 2013-09-01 10:10:33 UTC

Bulk closing of items that are on_qa and in old RHQ releases, which are out for a long time and where the issue has not been re-opened since.