#423: Truncate indexes when truncating a table

Summary: This revision modifies YugaByte DB to truncate secondary indexes when truncating a YCQL table.

Test Plan: TestTruncate.testTruncateWithIndex

Reviewers: bharat

Reviewed By: bharat

Subscribers: bogdan, yql

Differential Revision: https://phabricator.dev.yugabyte.com/D5281

java/yb-cql/src/test/java/org/yb/cql/TestTruncate.java

@@ -18,6 +18,8 @@
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertNull;
 
+import java.util.*;
+
 public class TestTruncate extends BaseCQLTest {
 
   @Test
@@ -48,6 +50,34 @@ public void testTruncate() throws Exception {
     assertNull(session.execute("select * from test_empty_truncate;").one());
   }
 
+  @Test
+  public void testTruncateWithIndex() throws Exception {
+    // Create table with index.
+    session.execute("create table test_truncate_index (k int primary key, v int) " +
+                    "with transactions = { 'enabled' : true };");
+    session.execute("create index test_truncate_index_idx on test_truncate_index (v);");
+
+    // Insert rows and verify.
+    final int ROW_COUNT = 100;
+    HashSet<String> results = new HashSet<>();
+    for (int i = 0; i < ROW_COUNT; i++) {
+      session.execute("insert into test_truncate_index (k, v) values (?, ?);",
+                      Integer.valueOf(i), Integer.valueOf(1000 + i));
+      results.add(String.format("Row[%d, %d]", i, 1000 + i));
+    }
+    assertQuery("select * from test_truncate_index;", results);
+
+    // Truncate rows, insert new ones and verify.
+    session.execute("truncate table test_truncate_index;");
+    results.clear();
+    for (int i = ROW_COUNT; i < ROW_COUNT * 2; i++) {
+      session.execute("insert into test_truncate_index (k, v) values (?, ?);",
+                      Integer.valueOf(i), Integer.valueOf(1000 + i));
+      results.add(String.format("Row[%d, %d]", i, 1000 + i));
+    }
+    assertQuery("select * from test_truncate_index;", results);
+  }
+
   @Test
   public void testInvalidTruncate() throws Exception {
     runInvalidStmt("truncate table invalid_namespace.test_truncate;");

src/yb/master/catalog_manager.cc

@@ -2100,29 +2100,49 @@ Status CatalogManager::TruncateTable(const TruncateTableRequestPB* req,
   RETURN_NOT_OK(CheckOnline());
 
   for (int i = 0; i < req->table_ids_size(); i++) {
-    const auto& table_id = req->table_ids(i);
-    // Lookup the table and verify if it exists.
-    TRACE("Looking up table");
-    scoped_refptr<TableInfo> table = FindPtrOrNull(table_ids_map_, table_id);
-    if (table == nullptr) {
-      Status s = STATUS(NotFound, Substitute("The table for table_id $0 does not exist", table_id));
-      return SetupError(resp->mutable_error(), MasterErrorPB::TABLE_NOT_FOUND, s);
-    }
+    RETURN_NOT_OK(TruncateTable(req->table_ids(i), false /* is_index */, resp, rpc));
+  }
 
-    TRACE("Locking table");
-    auto l = table->LockForRead();
-    if (l->data().started_deleting() || l->data().is_deleted()) {
-      Status s = STATUS(NotFound, Substitute("The table $0 does not exist", table->ToString()));
-      return SetupError(resp->mutable_error(), MasterErrorPB::TABLE_NOT_FOUND, s);
-    }
+  return Status::OK();
+}
 
-    // Send a Truncate() request to each tablet in the table.
-    SendTruncateTableRequest(table);
+Status CatalogManager::TruncateTable(const TableId& table_id,
+                                     const bool is_index,
+                                     TruncateTableResponsePB* resp,
+                                     rpc::RpcContext* rpc) {
+  const char* table_type = is_index ? "index" : "table";
 
-    LOG(INFO) << "Successfully initiated TRUNCATE for " << table->ToString() << " per request from "
-              << RequestorString(rpc);
-    background_tasks_->Wake();
+  // Lookup the table and verify if it exists.
+  TRACE(Substitute("Looking up $0", table_type));
+  scoped_refptr<TableInfo> table = FindPtrOrNull(table_ids_map_, table_id);
+  if (table == nullptr) {
+    Status s = STATUS(NotFound, Substitute("The table for $0 id $1 does not exist",
+                                           table_type, table_id));
+    return SetupError(resp->mutable_error(), MasterErrorPB::TABLE_NOT_FOUND, s);
   }
+
+  TRACE(Substitute("Locking $0", table_type));
+  auto l = table->LockForRead();
+  DCHECK(is_index == !l->data().pb.indexed_table_id().empty());
+  if (l->data().started_deleting() || l->data().is_deleted()) {
+    Status s = STATUS(NotFound, Substitute("The $0 $1 does not exist",
+                                           table_type, table->ToString()));
+    return SetupError(resp->mutable_error(), MasterErrorPB::TABLE_NOT_FOUND, s);
+  }
+
+  // Send a Truncate() request to each tablet in the table.
+  SendTruncateTableRequest(table);
+
+  LOG(INFO) << "Successfully initiated TRUNCATE for " << table->ToString() << " per request from "
+            << RequestorString(rpc);
+  background_tasks_->Wake();
+
+  // Truncate indexes also.
+  DCHECK(!is_index || l->data().pb.indexes().empty()) << "indexes should be empty for index table";
+  for (const auto& index_info : l->data().pb.indexes()) {
+    RETURN_NOT_OK(TruncateTable(index_info.table_id(), true /* is_index */, resp, rpc));
+  }
+
   return Status::OK();
 }
 

src/yb/master/catalog_manager.h

@@ -1356,6 +1356,12 @@ class CatalogManager : public tserver::TabletPeerLookupIf {
   // Start the background task to send the TruncateTable() RPC to the leader for this tablet.
   void SendTruncateTabletRequest(const scoped_refptr<TabletInfo>& tablet);
 
+  // Truncate the specified table/index.
+  CHECKED_STATUS TruncateTable(const TableId& table_id,
+                               bool is_index,
+                               TruncateTableResponsePB* resp,
+                               rpc::RpcContext* rpc);
+
   // Delete the specified table in memory. The TableInfo, DeletedTableInfo and lock of the deleted
   // table are appended to the lists. The caller will be responsible for committing the change and
   // deleting the actual table and tablets.