facebook/rocksdb v9.8.4 on GitHub

9.8.4 (11/18/2024)

When Remote Compaction is enabled, do not purge OPTIONS file immediately by DeleteObsoleteOptionsFiles() after SetOptions(). Rely on PurgeObsoleteFiles() to clean up obsolete OPTIONS file after each compaction.

Added a new API Transaction::GetAttributeGroupIterator that can be used to create a multi-column-family attribute group iterator over the specified column families, including the data from both the transaction and the underlying database. This API is currently supported for optimistic and write-committed pessimistic transactions.

BaseDeltaIterator now calls PrepareValue on the base iterator in case it has been created with the allow_unprepared_value read option set. Earlier, such base iterators could lead to incorrect values being exposed from BaseDeltaIterator.
Fix a bug for replaying WALs for WriteCommitted transaction DB when its user-defined timestamps setting is toggled on/off between DB sessions.

Fix a leak of obsolete blob files left open until DB::Close(). This bug was introduced in version
9.4.0.

All non-block_cache options in BlockBasedTableOptions are now mutable with DB::SetOptions().
See also Bug Fixes below.
When using iterators with BlobDB, it is now possible to load large values on an on-demand basis, i
.e. only if they are actually needed by the application. This can save I/O in use cases where the va
lues associated with certain keys are not needed. For more details, see the new read option allow_u nprepared_value and the iterator API PrepareValue.
Add a new file ingestion option IngestExternalFileOptions::fill_cache to support not adding bloc
ks from ingested files into block cache during file ingestion.
The option allow_unprepared_value is now also supported for multi-column-family iterators (i.e.
CoalescingIterator and AttributeGroupIterator).
When a file with just one range deletion (standalone range deletion file) is ingested via bulk loa
ding, it will be marked for compaction. During compaction, this type of files can be used to directl
y filter out some input files that are not protected by any snapshots and completely deleted by the
standalone range deletion file.

During file ingestion, overlapping files level assignment are done in multiple batches, so that th
ey can potentially be assigned to lower levels other than always land on L0.
OPTIONS file to be loaded by remote worker is now preserved so that it does not get purged by the
primary host. A similar technique as how we are preserving new SST files from getting purged is used
for this. min_options_file_numbers_ is tracked like pending_outputs_ is tracked.
Trim readahead_size during scans so data blocks containing keys that are not in the same prefix as
the seek key in Seek() are not prefetched when ReadOptions::auto_readahead_size=true (default v
alue) and ReadOptions::prefix_same_as_start = true
Assigning levels for external files are done in the same way for universal compaction and leveled
compaction. The old behavior tends to assign files to L0 while the new behavior will assign the file
s to the lowest level possible.

Fix a longstanding race condition in SetOptions for block_based_table_factory options. The fix h
as some subtle behavior changes because of copying and replacing the TableFactory on a change with S
etOptions, including requiring an Iterator::Refresh() for an existing Iterator to use the latest opt
ions.
Fix under counting of allocated memory in the compressed secondary cache due to looking at the com
pressed block size rather than the actual memory allocated, which could be larger due to internal fr
agmentation.
GetApproximateMemTableStats() could return disastrously bad estimates 5-25% of the time. The fun
ction has been re-engineered to return much better estimates with similar CPU cost.
Skip insertion of compressed blocks in the secondary cache if the lowest_used_cache_tier DB option
is kVolatileTier.
Fix an issue in level compaction where a small CF with small compaction debt can cause the DB to a
llow parallel compactions. (#13054)
Several DB option settings could be lost through GetOptionsFromString(), possibly elsewhere as w
ell. Affected options, now fixed:background_close_inactive_wals, write_dbid_to_manifest, write_ identity_file, prefix_seek_opt_in_only