Kathey Marsden wrote:
Mike Matrigali wrote:
Then you could figure out how important container 1105
is. The best case is if 1105 is an index then one need only drop the
index and recreate it. From the conglomerate id I think it is an
index:
Once you get your database in a bootable state you can identify the
container with one of the following queries.
Hi Mike and Kathey,
Thank you very much for your helpful replies. As suggested, I wrote a
hacked version of Derby to ignore this page during the log redo phase.
The database booted up, and thankfully, the corrupted page was in an
index, so I was able to drop it, and recreate it and now all is well.
For the record, I've attached the patch I made to Derby in case somebody
else can benefit from it. In this situation, I ran Derby's ij command with:
java -cp derby.jar;derbytools.jar
-Dorg.apache.derby.skipPagesDuringRecovery=3586
The system property specifies a comma separated string of page IDs to
ignore during the log redo phase.
I realise this is hackery, but would there be any benefit for a polished
version of this to go into the main code? Sadly, corruption is a fact
of life, whether it is due to software or hardware (or humans)..
--
Cheers,
David
Nuix Pty Ltd
Suite 79, 89 Jones St, Ultimo NSW 2007, Australia Ph: +61 2 9280 0699
Web: http://www.nuix.com Fax: +61 2 9212 6902
Index:
dist/java/engine/org/apache/derby/impl/store/raw/data/PageBasicOperation.java
===================================================================
---
dist/java/engine/org/apache/derby/impl/store/raw/data/PageBasicOperation.java
(revision 6493)
+++
dist/java/engine/org/apache/derby/impl/store/raw/data/PageBasicOperation.java
Thu Jun 11 16:33:52 EST 2009
@@ -52,7 +52,11 @@
import java.io.ObjectOutput;
import java.io.ObjectInput;
import java.io.IOException;
+import java.util.Set;
+import java.util.HashSet;
+
import org.apache.derby.iapi.services.io.LimitObjectInput;
+import org.apache.derby.iapi.services.monitor.Monitor;
/**
A PageBasicOperation changed the content of a page, this is the root class
of all
@@ -157,6 +161,28 @@
public final boolean needsRedo(Transaction xact)
throws StandardException
{
+ // Skip certain pages during recovery if we have corrupted pages as a
+ // way of trying to get a corrupted database into a useable state.
+ if (pageId != null)
+ {
+ String skipPagesProperty =
System.getProperty("org.apache.derby.skipPagesDuringRecovery");
+ Set skipPages = new HashSet();
+ if (skipPagesProperty != null)
+ {
+ String[] skipPagesArray = skipPagesProperty.split(",");
+ for (int i = 0; i < skipPagesArray.length; i++)
+ {
+ skipPages.add(new Long(Long.parseLong(skipPagesArray[i])));
+ }
+ }
+
+ if (skipPages.contains(new Long(pageId.getPageNumber())))
+ {
+ Monitor.getStream().println("Skipping page " +
pageId.getPageNumber() + " during log redo");
+ return false;
+ }
+ }
+
if (findpage(xact) == null) // committed dropped container
return false;
