DeleteRange() return NotSupported if row_cache is configured (#12512)

Summary:
...since this feature combination is not supported yet (https://github.com/facebook/rocksdb/issues/4122).

Pull Request resolved: https://github.com/facebook/rocksdb/pull/12512

Test Plan: new unit test.

Reviewed By: jaykorean, jowlyzhang

Differential Revision: D55820323

Pulled By: cbi42

fbshipit-source-id: eeb5e97d15c9bdc388793a2fb8e52cfa47e34bcf

db/db_basic_test.cc

@@ -464,12 +464,14 @@ TEST_F(DBBasicTest, TimedPutBasic) {
     ASSERT_EQ("bv1", Get(1, "bar"));
     ASSERT_OK(TimedPut(1, "baz", "bzv1", /*write_unix_time=*/0));
     ASSERT_EQ("bzv1", Get(1, "baz"));
+    if (option_config_ != kRowCache) {
       std::string range_del_begin = "b";
       std::string range_del_end = "baz";
       Slice begin_rdel = range_del_begin, end_rdel = range_del_end;
       ASSERT_OK(
           db_->DeleteRange(WriteOptions(), handles_[1], begin_rdel, end_rdel));
       ASSERT_EQ("NOT_FOUND", Get(1, "bar"));
+    }
 
     ASSERT_EQ("bzv1", Get(1, "baz"));
     ASSERT_OK(SingleDelete(1, "baz"));

db/db_range_del_test.cc

@@ -3806,6 +3806,21 @@ TEST_F(DBRangeDelTest, RefreshWithSnapshot) {
   iter.reset();
   db_->ReleaseSnapshot(snapshot);
 }
+
+TEST_F(DBRangeDelTest, RowCache) {
+  Options options = CurrentOptions();
+  options.row_cache = NewLRUCache(8 << 10);
+  DestroyAndReopen(options);
+  ASSERT_OK(Put(Key(3), "val"));
+  ASSERT_TRUE(db_->DeleteRange(WriteOptions(), db_->DefaultColumnFamily(),
+                               Key(3), Key(5))
+                  .IsNotSupported());
+  WriteBatch wb;
+  ASSERT_OK(wb.Put(Key(6), "abc"));
+  ASSERT_OK(wb.DeleteRange(Key(1), Key(5)));
+  ASSERT_TRUE(db_->Write(WriteOptions(), &wb).IsNotSupported());
+  ASSERT_EQ(Get(Key(3)), "val");
+}
 }  // namespace ROCKSDB_NAMESPACE
 
 int main(int argc, char** argv) {

db/db_test_util.cc

@@ -154,6 +154,9 @@ bool DBTestBase::ShouldSkipOptions(int option_config, int skip_mask) {
   if ((skip_mask & kSkipMmapReads) && option_config == kWalDirAndMmapReads) {
     return true;
   }
+  if ((skip_mask & kSkipRowCache) && option_config == kRowCache) {
+    return true;
+  }
   return false;
 }
 

db/db_test_util.h

@@ -1071,6 +1071,7 @@ class DBTestBase : public testing::Test {
     kSkipNoSeekToLast = 32,
     kSkipFIFOCompaction = 128,
     kSkipMmapReads = 256,
+    kSkipRowCache = 512,
   };
 
   const int kRangeDelSkipConfigs =
@@ -1078,7 +1079,9 @@ class DBTestBase : public testing::Test {
       kSkipPlainTable |
       // MmapReads disables the iterator pinning that RangeDelAggregator
       // requires.
-      kSkipMmapReads;
+      kSkipMmapReads |
+      // Not compatible yet.
+      kSkipRowCache;
 
   // `env_do_fsync` decides whether the special Env would do real
   // fsync for files and directories. Skipping fsync can speed up

db/write_batch.cc

@@ -2514,6 +2514,11 @@ class MemTableInserter : public WriteBatch::Handler {
     assert(ret_status.ok());
 
     if (db_ != nullptr) {
+      if (db_->immutable_db_options().row_cache) {
+        ret_status.PermitUncheckedError();
+        return Status::NotSupported(
+            "DeleteRange is not compatible with row cache.");
+      }
       auto cf_handle = cf_mems_->GetColumnFamilyHandle();
       if (cf_handle == nullptr) {
         cf_handle = db_->DefaultColumnFamily();

include/rocksdb/db.h

@@ -541,6 +541,8 @@ class DB {
   // 2) Limiting the maximum number of open files in the presence of range
   // tombstones can degrade read performance. To avoid this problem, set
   // max_open_files to -1 whenever possible.
+  // 3) Incompatible with row_cache, will return Status::NotSupported() if
+  // row_cache is configured.
   virtual Status DeleteRange(const WriteOptions& options,
                              ColumnFamilyHandle* column_family,
                              const Slice& begin_key, const Slice& end_key);

include/rocksdb/options.h

@@ -1223,6 +1223,8 @@ struct DBOptions {
   bool allow_2pc = false;
 
   // A global cache for table-level rows.
+  // Used to speed up Get() queries.
+  // NOTE: does not work with DeleteRange() yet.
   // Default: nullptr (disabled)
   std::shared_ptr<RowCache> row_cache = nullptr;
 

unreleased_history/public_api_changes/delete_range_rowcache.md

@@ -0,0 +1 @@
+* DeleteRange() will return NotSupported() if row_cache is configured since they don't work together in some cases.