Summary:
Uses a newer build toolchain but the same old GLIBC when building releases of RocksJava for Linux x64 in the Docker Container.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4756

Differential Revision: D13383575

Pulled By: sagar0

fbshipit-source-id: 27c58814876e434d5fa61395e6664cfc5f6830b1

Summary:
Refactored and simplified `BlockBasedTable::Open` to be similar to `BlockBasedTableBuilder::Finish` as both these functions complement each other. Also added `BlockBasedTableBuilder::WriteFooter` along the way.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4636

Differential Revision: D12933319

Pulled By: sagar0

fbshipit-source-id: 1ff1d02f6d80a63b5ba720a1fc75e71c7344137b

Summary:
the original test does not give enough time difference between tombstone write time and the expire time point, which make test flaky.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4755

Reviewed By: maysamyabandeh

Differential Revision: D13369681

Pulled By: wpc

fbshipit-source-id: 22576f354c63cd0b39d8b35c3913303707503ea9

Summary:
Transaction::GetForUpdate is extended with a do_validate parameter with default value of true. If false it skips validating the snapshot (if there is any) before doing the read. After the read it also returns the latest value (expects the ReadOptions::snapshot to be nullptr). This allows RocksDB applications to use GetForUpdate similarly to how InnoDB does. Similarly ::Merge, ::Put, ::Delete, and ::SingleDelete are extended with assume_exclusive_tracked with default value of false. It true it indicates that call is assumed to be after a ::GetForUpdate(do_validate=false).
The Java APIs are accordingly updated.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4680

Differential Revision: D13068508

Pulled By: maysamyabandeh

fbshipit-source-id: f0b59db28f7f6a078b60844d902057140765e67d

Summary:
As titled. Update history to include a recent bug fix in
9be3e6b4.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4753

Differential Revision: D13350286

Pulled By: riversand963

fbshipit-source-id: b6324780dee4cb1757bc2209403a08531c150c08

Summary:
When write stall has already been triggered due to number of L0 files reaching
threshold, file ingestion must proceed with its flush without waiting for the
write stall condition to cleared by the compaction because compaction can wait
for ingestion to finish (circular wait).

In order to avoid this wait, we can set `FlushOptions.allow_write_stall` to be
true (default is false). Setting it to false can cause deadlock.

This can happen when the number of compaction threads is low.

Considere the following
```
Time  compaction_thread                        ingestion_thread
 |                                             num_running_ingest_file_++
 |    while(num_running_ingest_file_>0){wait}
 |                                             flush
 V
```
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4751

Differential Revision: D13343037

Pulled By: riversand963

fbshipit-source-id: d3b95938814af46ec4c463feff0b50c70bd8b23f

Summary:
Test plan
```
$make clean && make -j32 all check
```
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4752

Differential Revision: D13344705

Pulled By: riversand963

fbshipit-source-id: fc3a43174d09d70ccc2b09decd78e1da1b6ba9d1

Summary:
Don't enable ROCKSDB_JEMALLOC unless the build mode is opt and default
allocator is jemalloc. In dev mode, this is causing compile/link errors such as -
```
stderr: buck-out/dev/gen/rocksdb/src/rocksdb_lib#compile-pic-malloc_stats.cc.o4768b59e,gcc-5-glibc-2.23-clang/db/malloc_stats.cc.o:malloc_stats.cc:function rocksdb::DumpMallocStats(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >*): error: undefined reference to 'malloc_stats_print'
clang-7.0: error: linker command failed with exit code 1
```
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4747

Differential Revision: D13324840

Pulled By: anand1976

fbshipit-source-id: 45ffbd4f63fe4d9e8a0473d8f066155e4ef64a14

Summary:
…) (#4702)"

This reverts commit 3a18bb3e.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4744

Differential Revision: D13311869

Pulled By: miasantreble

fbshipit-source-id: 6300b12cc34828d8b9274e907a3aef1506d5d553

Summary: Pull Request resolved: https://github.com/facebook/rocksdb/pull/4704

Differential Revision: D13283300

Pulled By: gfosco

fbshipit-source-id: cb4fdaa93137e0bba64b781ba7e8fe31b19e5656

Summary:
Current implementation of `current_over_upper_bound_` fails to take into consideration that keys might be invalid in either base iterator or delta iterator. Calling key() in such scenario will lead to assertion failure and runtime errors.
This PR addresses the bug by adding check for valid keys before calling `IsOverUpperBound()`, also added test coverage for iterate_upper_bound usage in BaseDeltaIterator
Also recommit https://github.com/facebook/rocksdb/pull/4656 (It was reverted earlier due to bugs)
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4702

Differential Revision: D13146643

Pulled By: miasantreble

fbshipit-source-id: 6d136929da12d0f2e2a5cea474a8038ec5cdf1d0

Summary:
Full block (use_block_based_builder=false) Bloom filter has clear CPU saving benefits but with limitation of using temp memory when building an SST file proportional to the SST file size. We reduced the chance of having large SST files with multi-level universal compaction. Now we change to a default with better performance.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4735

Differential Revision: D13266674

Pulled By: siying

fbshipit-source-id: 7594a4c3e32568a5a2adce22bb0e46553e55c602

Summary:
Currently tests are failing on master with the following message:
> util/jemalloc_nodump_allocator.cc:132:8: error: unused parameter ‘options’ [-Werror=unused-parameter]
 Status NewJemallocNodumpAllocator(

This PR attempts to fix the issue
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4738

Differential Revision: D13278804

Pulled By: miasantreble

fbshipit-source-id: 64a6204aa685bd85d8b5080655cafef9980fac2f

Summary:
The fix in #4727 for double snapshot release was incomplete since it does not properly remove the duplicate entires in the snapshot list after finding that a snapshot is still valid. The patch does that and also improves the unit test to show the issue.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4734

Differential Revision: D13266260

Pulled By: maysamyabandeh

fbshipit-source-id: 351e2c40cca45a87b757774c11af74182314911e

Summary:
Add option to limit tcache usage by allocation size. This is to reduce total tcache size in case there are many user threads accessing the allocator and incur non-trivial memory usage.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4736

Differential Revision: D13269305

Pulled By: yiwu-arbug

fbshipit-source-id: 95a9b7fc67facd66837c849137e30e137112e19d

Summary:
**Summary:**
Simplified the code layout by moving FIFOCompactionPicker to a separate file.
**Why?:**
While trying to add ttl functionality to universal compaction, I found that `FIFOCompactionPicker` class and its impl methods to be interspersed between `LevelCompactionPicker` methods which kind-of made the code a little hard to traverse. So I moved `FIFOCompactionPicker` to a separate compaction_picker_fifo.h/cc file, similar to `UniversalCompactionPicker`.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4724

Differential Revision: D13227914

Pulled By: sagar0

fbshipit-source-id: 89471766ea67fa4d87664a41c057dd7df4b3d4e3

Summary:
There is a race condition in DBFlushTest.SyncFail, as illustrated below.
```
time         thread1                             bg_flush_thread
  |     Flush(wait=false, cfd)
  |     refs_before=cfd->current()->TEST_refs()   PickMemtable calls cfd->current()->Ref()
  V
```
The race condition between thread1 getting the ref count of cfd's current
version and bg_flush_thread incrementing the cfd's current version makes it
possible for later assertion on refs_before to fail. Therefore, we add test
sync points to enforce the order and assert on the ref count before and after
PickMemtable is called in bg_flush_thread.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4633

Differential Revision: D12967131

Pulled By: riversand963

fbshipit-source-id: a99d2bacb7869ec5d8d03b24ef2babc0e6ae1a3b

Summary:
there is chance that

* the caller tries to repair the db when holding the db_lock, in
  that case the env implementation might not set the `lock`
  parameter of Repairer::Run().
* the caller somehow never calls Repairer::Run().

either way, the desctructor of Repair will compare the uninitialized
db_lock_ with nullptr, and tries to unlock it. there is good chance
that the db_lock_ is not nullptr, then boom.
Signed-off-by: NKefu Chai <tchaikov@gmail.com>
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4683

Differential Revision: D13260287

Pulled By: riversand963

fbshipit-source-id: 878a119d2e9f10a0fa17ee62cf3fb24b33d49fa5

Summary:
Add a dummy main() in sst_file_reader_test for ROCKSDB_LITE to fix link failure in regression
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4725

Differential Revision: D13252885

Pulled By: anand1976

fbshipit-source-id: 0e22b964815e2bf01aff7d03ed4ae59d44fa86f1

Summary:
Currently the garbage collection of items in old_commit_map_ was done upon ::ReleaseSnapshot. The assumption behind this method was that the sequence number of snapshots are unique, which is incorrect. In the very rare cases that two consecutive snapshot have the same sequence number this could lead the release of the first snapshot affect the old_commit_map_ that is necessary to service the reads of the second snapshot. The bug would be triggered only if i) two snapshot have the same seq, ii) both of them are very old (older than the last ~4m transactions), and iii) there is commit entry overlapping with the snapshot seq number.
It is fixed by doing the cleanup of old_commit_map_ in UpdateSnapshot: the new list of snapshots are compared with the old one and the missing sequence numbers are concluded released. If two snapshots have the same seq number, after the release of one of them, the seq number still appears in the snapshot least and thus not cleaned up prematurely.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4727

Differential Revision: D13246495

Pulled By: maysamyabandeh

fbshipit-source-id: 93b87a5042afd8060889df245526d3f5d29de9fe

Summary:
Fix block based table reader not using memory_allocator when allocating index blocks and compression dictionary blocks.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4678

Differential Revision: D13054594

Pulled By: yiwu-arbug

fbshipit-source-id: 379f25bcc665395662511c4f873f4b7b55104ce2

Summary:
Removed `one_time_use` flag, which removed the need for some
tests, and changed all `NewRangeTombstoneIterator` methods to return
`FragmentedRangeTombstoneIterators`.

These changes also led to removing `RangeDelAggregatorV2::AddUnfragmentedTombstones`
and one of the `MemTableListVersion::AddRangeTombstoneIterators` methods.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4692

Differential Revision: D13106570

Pulled By: abhimadan

fbshipit-source-id: cbab5432d7fc2d9cdfd8d9d40361a1bffaa8f845

Summary:
If user do not end the trace manually, the tracing will continue which can potential use up all the storage space and cause problem. In this PR, the max trace file size is added to the TraceOptions and user can set the value if they need or the default is 64GB.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4610

Differential Revision: D12893400

Pulled By: zhichao-cao

fbshipit-source-id: acf4b5a6076bb691778bdfbac4864e1006758953

Summary:
Mac build is failing with the below error:
```
$ make db_bench -j8
...
...
tools/db_bench_tool.cc:4583:25: error: no matching function for call to 'max'
              (uint64_t)std::max(0l, seek_pos - FLAGS_max_scan_distance),
                        ^~~~~~~~
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/include/c++/v1/algorithm:2717:1: note: candidate template ignored: deduced conflicting types for parameter '_Tp' ('long' vs. 'long long')
max(const _Tp& __a, const _Tp& __b)
^
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/include/c++/v1/algorithm:2727:1: note: candidate template ignored: could not match 'initializer_list<type-parameter-0-0>' against 'long'
max(initializer_list<_Tp> __t, _Compare __comp)
^
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/include/c++/v1/algorithm:2709:1: note: candidate function template not viable: requires 3 arguments, but 2 were provided
max(const _Tp& __a, const _Tp& __b, _Compare __comp)
^
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/include/c++/v1/algorithm:2735:1: note: candidate function template not viable: requires single argument '__t', but 2 arguments were provided
max(initializer_list<_Tp> __t)
^
1 error generated.
make: *** [tools/db_bench_tool.o] Error 1
```

My compiler version:
Mac OS X Mojave
```
$ clang++ --version
Apple LLVM version 10.0.0 (clang-1000.11.45.5)
Target: x86_64-apple-darwin18.2.0
Thread model: posix
InstalledDir: /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin
```
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4722

Differential Revision: D13220196

Pulled By: sagar0

fbshipit-source-id: 01e5e928288a5613027c83a26ad8aedf04438b14

Summary:
A user friendly sst file reader is useful when we want to access sst
files outside of RocksDB. For example, we can generate an sst file
with SstFileWriter and send it to other places, then use SstFileReader
to read the file and process the entries in other ways.

Also rename the original SstFileReader to SstFileDumper because of
name conflict, and seems SstFileDumper is more appropriate for tools.

TODO: there is only a very simple test now, because I want to get some feedback first.
If the changes look good, I will add more tests soon.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4717

Differential Revision: D13212686

Pulled By: ajkr

fbshipit-source-id: 737593383264c954b79e63edaf44aaae0d947e56

Summary:
Simple patch to address comments in [statistics.h#L65](https://github.com/facebook/rocksdb/blob/master/monitoring/statistics.h#L65|statistics.h#L65)  `TODO(ajkr): clean this up since there are no internal stats anymore`
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4714

Differential Revision: D13208093

Pulled By: ajkr

fbshipit-source-id: 4468badb850592411147539f859082644f5296f6

Summary:
DeleteRange is now ready for production use. Change the header comment to reflect this, and update HISTORY.md with the feature's status.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4709

Differential Revision: D13209055

Pulled By: abhimadan

fbshipit-source-id: 65423eb1a4927cf593c38254cd87c322f73ae137

Summary:
Adding sanity check test for mapping of `Histograms` and `HistogramsNameMap`

```
[==========] Running 2 tests from 1 test case.
[----------] Global test environment set-up.
[----------] 2 tests from StatisticsTest
[ RUN      ] StatisticsTest.SanityTickers
[       OK ] StatisticsTest.SanityTickers (0 ms)
[ RUN      ] StatisticsTest.SanityHistograms
[       OK ] StatisticsTest.SanityHistograms (0 ms)
[----------] 2 tests from StatisticsTest (0 ms total)

[----------] Global test environment tear-down
[==========] 2 tests from 1 test case ran. (0 ms total)
[  PASSED  ] 2 tests.
```
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4720

Differential Revision: D13217061

Pulled By: ajkr

fbshipit-source-id: 6427f4e684c36b2f3c3440808b74fee86a364683

Summary:
Added back `NO_ITERATORS` and moved `NO_ITERATOR_CREATED` to the end of `toCppTickers`.

This is a leftover fix which is needed in addition to a138e351 to correctly convert java tickers to c++ tickers. a138e351 only updated `toJavaTickerType` but both `toJavaTickerType` and `toCppTickers` need to be changed.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4719

Differential Revision: D13208847

Pulled By: sagar0

fbshipit-source-id: 53a42f3d6ffe04034acfde972d73040b92b4c1af

Summary:
The error message of databases/rocksdb-lite (FreeBSD port) is as follows:
```
  tools/db_bench_tool.cc:1976:16: error: private field 'trace_options_' is not used [-Werror,-Wunused-private-field]
    TraceOptions trace_options_;
                 ^
```
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4715

Differential Revision: D13207902

Pulled By: ajkr

fbshipit-source-id: be3c612eba656aeddb77e35e2f201dd25dc92f7e

Summary:
Summary

We should declare constants in headers and define them in source files.
But this commit is only aimed at compound types.

I don't know if it is necessary to do the same thing to fundamental types.

I used this command to find all of the constant definitions in header files.

`find . -name "*.h" | xargs grep -e "^const .*=.*"`

And here is what I found:

```
./db/version_edit.h:const uint64_t kFileNumberMask = 0x3FFFFFFFFFFFFFFF;
./include/rocksdb/env.h:const size_t kDefaultPageSize = 4 * 1024;
./include/rocksdb/statistics.h:const std::vector<std::pair<Tickers, std::string>> TickersNameMap = {
./include/rocksdb/statistics.h:const std::vector<std::pair<Histograms, std::string>> HistogramsNameMap = {
./include/rocksdb/table.h:const uint32_t kPlainTableVariableLength = 0;
./include/rocksdb/utilities/transaction_db.h:const uint32_t kInitialMaxDeadlocks = 5;
./port/port_posix.h:const uint32_t kMaxUint32 = std::numeric_limits<uint32_t>::max();
./port/port_posix.h:const int kMaxInt32 = std::numeric_limits<int32_t>::max();
./port/port_posix.h:const uint64_t kMaxUint64 = std::numeric_limits<uint64_t>::max();
./port/port_posix.h:const int64_t kMaxInt64 = std::numeric_limits<int64_t>::max();
./port/port_posix.h:const size_t kMaxSizet = std::numeric_limits<size_t>::max();
./port/win/port_win.h:const uint32_t kMaxUint32 = UINT32_MAX;
./port/win/port_win.h:const int kMaxInt32 = INT32_MAX;
./port/win/port_win.h:const int64_t kMaxInt64 = INT64_MAX;
./port/win/port_win.h:const uint64_t kMaxUint64 = UINT64_MAX;
./port/win/port_win.h:const size_t kMaxSizet = UINT64_MAX;
./port/win/port_win.h:const size_t kMaxSizet = UINT_MAX;
./port/win/port_win.h:const uint32_t kMaxUint32 = std::numeric_limits<uint32_t>::max();
./port/win/port_win.h:const int kMaxInt32 = std::numeric_limits<int>::max();
./port/win/port_win.h:const uint64_t kMaxUint64 = std::numeric_limits<uint64_t>::max();
./port/win/port_win.h:const int64_t kMaxInt64 = std::numeric_limits<int64_t>::max();
./port/win/port_win.h:const size_t kMaxSizet = std::numeric_limits<size_t>::max();
./port/win/port_win.h:const bool kLittleEndian = true;
./table/cuckoo_table_factory.h:const uint32_t kCuckooMurmurSeedMultiplier = 816922183;
./table/data_block_hash_index.h:const uint8_t kNoEntry = 255;
./table/data_block_hash_index.h:const uint8_t kCollision = 254;
./table/data_block_hash_index.h:const uint8_t kMaxRestartSupportedByHashIndex = 253;
./table/data_block_hash_index.h:const size_t kMaxBlockSizeSupportedByHashIndex = 1u << 16;
./table/data_block_hash_index.h:const double kDefaultUtilRatio = 0.75;
./table/filter_block.h:const uint64_t kNotValid = ULLONG_MAX;
./table/format.h:const int kMagicNumberLengthByte = 8;
./third-party/fbson/FbsonJsonParser.h:const char* const kJsonDelim = " ,]}\t\r\n";
./third-party/fbson/FbsonJsonParser.h:const char* const kWhiteSpace = " \t\n\r";
./third-party/gtest-1.7.0/fused-src/gtest/gtest.h:const BiggestInt kMaxBiggestInt =
./third-party/gtest-1.7.0/fused-src/gtest/gtest.h:const char kDeathTestStyleFlag[] = "death_test_style";
./third-party/gtest-1.7.0/fused-src/gtest/gtest.h:const char kDeathTestUseFork[] = "death_test_use_fork";
./third-party/gtest-1.7.0/fused-src/gtest/gtest.h:const char kInternalRunDeathTestFlag[] = "internal_run_death_test";
./third-party/gtest-1.7.0/fused-src/gtest/gtest.h:const char* pets[] = {"cat", "dog"};
./third-party/gtest-1.7.0/fused-src/gtest/gtest.h:const size_t kProtobufOneLinerMaxLength = 50;
./third-party/gtest-1.7.0/fused-src/gtest/gtest.h:const int kMaxStackTraceDepth = 100;
./third-party/gtest-1.7.0/fused-src/gtest/gtest.h:const T* WithParamInterface<T>::parameter_ = NULL;
./util/coding.h:const unsigned int kMaxVarint64Length = 10;
./util/filename.h:const size_t kFormatFileNumberBufSize = 38;
./util/testutil.h:const SliceTransform* RandomSliceTransform(Random* rnd, int pre_defined = -1);
./util/trace_replay.h:const std::string kTraceMagic = "feedcafedeadbeef";
./util/trace_replay.h:const unsigned int kTraceTimestampSize = 8;
./util/trace_replay.h:const unsigned int kTraceTypeSize = 1;
./util/trace_replay.h:const unsigned int kTracePayloadLengthSize = 4;
./util/trace_replay.h:const unsigned int kTraceMetadataSize =
./utilities/cassandra/serialize.h:const int64_t kCharMask = 0xFFLL;
./utilities/cassandra/serialize.h:const int32_t kBitsPerByte = 8;
```

And these 3 lines are related to this commit:

```
./include/rocksdb/statistics.h:const std::vector<std::pair<Tickers, std::string>> TickersNameMap = {
./include/rocksdb/statistics.h:const std::vector<std::pair<Histograms, std::string>> HistogramsNameMap = {
./util/trace_replay.h:const std::string kTraceMagic = "feedcafedeadbeef";
```

Any comments would be appreciated.
Thanks.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4691

Differential Revision: D13208049

Pulled By: ajkr

fbshipit-source-id: e5ee55fdaec5447fc5798c6721e2821e7cdc0d5b

Summary:
Make CompactionOptionsFIFO's ttl and allow_compaction options to be available in RocksJava.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4609

Differential Revision: D12849503

Pulled By: sagar0

fbshipit-source-id: 47baa97918d252370f234c36c1af15ff2dad7658

Summary:
Previously, every range tombstone iterator was seeked on every
ShouldDelete call, which quickly degraded performance for long range
scans. This PR improves performance by tracking iterator positions and
only advancing iterators when necessary.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4677

Differential Revision: D13205373

Pulled By: abhimadan

fbshipit-source-id: 80c199dace1e19362a4c61c686bf01913eae87cb

Summary:
… (#4656)"

This reverts commit b76398a8.

Will add test coverage for iterate_upper_bound before re-commit b76398
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4705

Differential Revision: D13148592

Pulled By: miasantreble

fbshipit-source-id: 4d1ce0bfd9f7a5359a7688bd780eb06a66f45b1f

Summary:
as titled
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4711

Differential Revision: D13166391

Pulled By: ajkr

fbshipit-source-id: 3a3e537cebe2ba97a7ae6fcc3282db2ea755158e

Summary:
We haven't been populating `NO_FILE_CLOSES` since v1.5.8 even though it was never marked as deprecated. Start populating it again. Conveniently `DeleteTableReader` has an unused `void*` argument that we can use...

Blame: 63f216ee

Closes #4700.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4703

Differential Revision: D13146769

Pulled By: ajkr

fbshipit-source-id: ad8d6fb0493e701f60a165a3bca1787d255be008

Summary:
…ons (#4676)"

This reverts commit b32d087d.

`MemoryAllocator` needs to be with `Cache`, since cache entry can
outlive DB and block based table. The cache needs to hold reference to
memory allocator when deleting cache entry.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4697

Differential Revision: D13133490

Pulled By: yiwu-arbug

fbshipit-source-id: 8ef7e8a51263bfd929f892fd062665ff4ce9ce5a

Summary:
The old RangeDelAggregator did expensive pre-processing work
to create a collapsed, binary-searchable representation of range
tombstones. With FragmentedRangeTombstoneIterator, much of this work is
now unnecessary. RangeDelAggregatorV2 takes advantage of this by seeking
in each iterator to find a covering tombstone in ShouldDelete, while
doing minimal work in AddTombstones. The old RangeDelAggregator is still
used during flush/compaction for now, though RangeDelAggregatorV2 will
support those uses in a future PR.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4649

Differential Revision: D13146964

Pulled By: abhimadan

fbshipit-source-id: be29a4c020fc440500c137216fcc1cf529571eb3

Summary:
Since a range tombstone seen at one level will cover all keys
in the range at lower levels, there was a short-circuiting check in Get
that reported a key was not found at most one file after the range
tombstone was discovered. However, this was incorrect for merge
operands, since a deletion might only cover some merge operands,
which implies that the key should be found. This PR fixes this logic in
the Version portion of Get, and removes the logic from the MemTable
portion of Get, since the perforamnce benefit provided there is minimal.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4698

Differential Revision: D13142484

Pulled By: abhimadan

fbshipit-source-id: cbd74537c806032f2bfa564724d01a80df7c8f10

Summary:
- Added back the `NO_ITERATORS` that was removed in 5945e16d.
- Marked it as deprecated since it is no longer populated, but kept for API compatibility.
- Made sure the new tickers, `NO_ITERATOR_CREATED` and `NO_ITERATOR_DELETED`, are appended at the end of the enum, in case people are relying on the int values.

The change where `NO_ITERATOR_CREATED` and `NO_ITERATOR_DELETED` were introduced is unreleased so I believe it is ok to change their ordering.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4701

Differential Revision: D13142887

Pulled By: ajkr

fbshipit-source-id: 29a336ce5b46632ce50ad42ccc4a29013f71d6d6