Original issue 178 created by kevin.d.regan on 2013-06-13T01:12:41.000Z:

What steps will reproduce the problem?

1. Compile and run the included test program.
2. Note that not all value have been properly deleted.
3. Recompile the test program with the CompactRange call commented out.
4. Note that all values have been properly deleted.

What is the expected output? What do you see instead?

The expected output from the program is:

Creating first key range
Creating second key range
Deleting second key range
Compacting database
Counting number of keys left
Found 0 keys

The actual output is:

Creating first key range
Creating second key range
Deleting second key range
Compacting database
Counting number of keys left
Found 1222706 keys

What version of the product are you using? On what operating system?

1.9, 1.10
FreeBSD, Ubuntu 12.10

Please provide any additional information below.

include <iostream>

include <sstream>

include <cstdlib>

include <leveldb/db.h>

include <leveldb/write_batch.h>

namespace {

const std::string DB_PATH = "/tmp/my_test_db";
size_t NUM_KEYS = 1100000;

void
check_status(const leveldb::Status& status, const std::string& error_msg)
{
if (!status.ok()) {
std::cerr << "ERROR: " << error_msg << ": " <<
status.ToString() << std::endl;
std::exit(1);
}
}

std::string
create_key_1(size_t i)
{
std::ostringstream out;
out << "my_key_" << i;
return out.str();
}

std::string
create_key_2(size_t i)
{
return create_key_1(i) + "_xxx";
}

} // namespace

int
main (int argc, char** argv)
{
// open database
leveldb::DB* db;
leveldb::Options db_options;
db_options.create_if_missing = true;
leveldb::Status status = leveldb::DB::Open(db_options, DB_PATH, &db);
check_status(status, "Could not open database");

// create first key range
std::cout << "Creating first key range" << std::endl;
leveldb::WriteBatch batch;
for (size_t i = 0; i < NUM_KEYS; i++) {
    batch.Put(create_key_1(i), "value for range 1 key");
}
status = db->Write(leveldb::WriteOptions(), &batch);
check_status(status, "Could not create keys for first range");

// create second key range
std::cout << "Creating second key range" << std::endl;
batch.Clear();
for (size_t i = 0; i < NUM_KEYS; i++) {
    batch.Put(create_key_2(i), "value for range 2 key");
}
status = db->Write(leveldb::WriteOptions(), &batch);
check_status(status, "Could not create keys for second range");

// delete second key range
std::cout << "Deleting second key range" << std::endl;
batch.Clear();
for (size_t i = 0; i < NUM_KEYS; i++) {
    batch.Delete(create_key_2(i));
}
status = db->Write(leveldb::WriteOptions(), &batch);
check_status(status, "Could not delete keys");

// compact database
std::cout << "Compacting database" << std::endl;
db->CompactRange(NULL, NULL);

// count the keys
std::cout << "Counting number of keys left" << std::endl;
leveldb::Iterator* iter = db->NewIterator(leveldb::ReadOptions());;
size_t num_keys = 0;
for (iter->SeekToFirst(); iter->Valid(); iter->Next()) {
    num_keys++;
}
delete iter;
std::cout << "Found " << num_keys << " keys" << std::endl;

// close database
delete db;

}