Github user paul-rogers commented on a diff in the pull request:
https://github.com/apache/drill/pull/1059#discussion_r155939449
--- Diff:
exec/java-exec/src/test/java/org/apache/drill/exec/physical/impl/join/TestMergeJoinAdvanced.java
---
@@ -253,4 +259,75 @@ public void testDrill4196() throws Exception {
.baselineValues(6000*800L)
.go();
}
+
+ private void buildFile(String fileName, String[] data, File testDir)
throws IOException {
+ try(PrintWriter out = new PrintWriter(new FileWriter(new File(testDir,
fileName)))) {
+ for (String line : data) {
+ out.println(line);
+ }
+ }
+ }
+
+ @Test
+ public void testMergeLeftJoinWithEmptyTable() throws Exception {
+ ClusterFixtureBuilder builder = ClusterFixture.builder(dirTestWatcher);
+ File testDir = null;
+ try {
+ ClusterFixture cluster = builder.build();
+ ClientFixture client = cluster.clientFixture();
+ testDir = dirTestWatcher.getTmpDir();
+ cluster.defineWorkspace("dfs", "data", testDir.getAbsolutePath(),
"json");
+ buildFile("dept.json", new String[0], testDir);
+ QueryBuilder query = client.queryBuilder().sql("select * from
cp.`employee.json` emp left outer join dfs.data.`dept.json` as dept on
dept.manager = emp.`last_name`");
+ assert(query.futureSummary().get().recordCount() == 1155);
+ } catch (RuntimeException ex) {
+ throw ex;
+ } finally {
+ if (testDir != null) {
+ testDir.delete();
+ }
+ }
+ }
+
+ @Test
+ public void testMergeInnerJoinWithEmptyTable() throws Exception {
+ ClusterFixtureBuilder builder = ClusterFixture.builder(dirTestWatcher);
+ File testDir = null;
+ try {
+ ClusterFixture cluster = builder.build();
+ ClientFixture client = cluster.clientFixture();
+ testDir = dirTestWatcher.getTmpDir();
+ cluster.defineWorkspace("dfs", "data", testDir.getAbsolutePath(),
"json");
+ buildFile("dept.json", new String[0], testDir);
+ QueryBuilder query = client.queryBuilder().sql("select * from
cp.`employee.json` emp inner join dfs.data.`dept.json` as dept on dept.manager
= emp.`last_name`");
+ assert(query.futureSummary().get().recordCount() == 0);
--- End diff --
How could this test ensure that we did, indeed, stop the readers from
reading extra records? (That is, that the `kill()` calls worked?)
---
