Index removal is now batched - reducing memory requirements when removing

large indexes

1 files changed, 31 insertions, 1 deletions

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);

     }

 }