From 975fd9fec74313f52007ebb264a03ec68d33448d Mon Sep 17 00:00:00 2001
From: Tom Keller <keller_tl@users.sourceforge.net>
Date: Fri, 26 Jan 2007 19:36:20 +0000
Subject: Index removal is now batched - reducing memory requirements when
 removing large indexes

---
 RELEASE-NOTES.txt                                  |  2 ++
 pom.xml                                            |  8 +++++-
 .../carbonado/repo/indexed/IndexedStorage.java     | 32 +++++++++++++++++++++-
 3 files changed, 40 insertions(+), 2 deletions(-)

diff --git a/RELEASE-NOTES.txt b/RELEASE-NOTES.txt
index fdfb0cc..c09c49f 100644
--- a/RELEASE-NOTES.txt
+++ b/RELEASE-NOTES.txt
@@ -8,6 +8,8 @@ Carbonado change history
 - Added additional index selection tie-breaker if index is most likely defined
   to support desired ordering.
 - Support mapping JDBC numeric column to short or byte.
+- Index removal is now batched - reducing memory requirements when removing
+  large indexes
 
 1.1-BETA8 to 1.1-BETA9
 -------------------------------
diff --git a/pom.xml b/pom.xml
index ec4ae4e..6af176f 100644
--- a/pom.xml
+++ b/pom.xml
@@ -85,6 +85,12 @@
       <name>Doug Treder</name>
       <organization>Amazon Technologies, Inc.</organization>
     </developer>
+    <developer>
+    	<name>Tom Keller</name>
+    	<organization>Amazon Technologies, Inc.</organization>
+    	<id>keller_tl</id>
+    	<email>keller_tl@users.sourceforge.net</email>
+    </developer>
   </developers>
 
   <contributors>
@@ -206,4 +212,4 @@
       </plugin>
     </plugins>
   </reporting>
-</project>
\ No newline at end of file
+</project>
diff --git a/src/main/java/com/amazon/carbonado/repo/indexed/IndexedStorage.java b/src/main/java/com/amazon/carbonado/repo/indexed/IndexedStorage.java
index 9b7f408..5fb94eb 100644
--- a/src/main/java/com/amazon/carbonado/repo/indexed/IndexedStorage.java
+++ b/src/main/java/com/amazon/carbonado/repo/indexed/IndexedStorage.java
@@ -446,7 +446,37 @@ class IndexedStorage<S extends Storable> implements Storage<S>, StorageAccess<S>
 
         // Doesn't completely remove the index, but it should free up space.
         // TODO: when truncate method exists, call that instead
-        indexEntryStorage.query().deleteAll();
+        // TODO: set batchsize based on repository locktable size
+        int batchSize = 10;
+        while (true) {
+            Transaction txn = mRepository.getWrappedRepository()
+                .enterTopTransaction(IsolationLevel.READ_COMMITTED);
+            txn.setForUpdate(true);
+
+            try {
+                Cursor<? extends Storable> cursor = indexEntryStorage.query().fetch();
+                if (!cursor.hasNext()) {
+                    break;
+                }
+                int count = 0;
+                try {
+                    while (count++ < batchSize && cursor.hasNext()) {
+                        cursor.next().tryDelete();
+                    }
+                } finally {
+                    cursor.close();
+                }
+                if (txn != null) {
+                    txn.commit();
+                }
+            } catch (FetchException e) {
+                throw e.toPersistException();
+            } finally {
+                if (txn != null) {
+                    txn.exit();
+                }
+            }
+        }
         unregisterIndex(index);
     }
 }
-- 
cgit v1.2.3