ArchiveTask list-unused query optimization (apache#4600)

* ArchiveTask list unused query optimization * ArchiveTask list unused query optimization
bannaboxer · Jul 26, 2017 · 2005c55 · 2005c55
1 parent 684cfbf
commit 2005c55
Showing 1 changed file with 5 additions and 1 deletion.
diff --git a/server/src/main/java/io/druid/metadata/IndexerSQLMetadataStorageCoordinator.java b/server/src/main/java/io/druid/metadata/IndexerSQLMetadataStorageCoordinator.java
@@ -928,10 +928,14 @@ public List<DataSegment> getUnusedSegmentsForInterval(final String dataSource, f
           @Override
           public List<DataSegment> inTransaction(final Handle handle, final TransactionStatus status) throws Exception
           {
+            // 2 range conditions are used on different columns, but not all SQL databases properly optimize it.
+            // Some databases can only use an index on one of the columns. An additional condition provides
+            // explicit knowledge that 'start' cannot be greater than 'end'.
             return handle
                 .createQuery(
                     StringUtils.format(
-                        "SELECT payload FROM %1$s WHERE dataSource = :dataSource and start >= :start and %2$send%2$s <= :end and used = false",
+                        "SELECT payload FROM %1$s WHERE dataSource = :dataSource and start >= :start "
+                        + "and start <= :end and %2$send%2$s <= :end and used = false",
                         dbTables.getSegmentsTable(), connector.getQuoteString()
                     )
                 )