2.5.0

• Add rename_table() and rename_multimap_table()
• Add Key and Value implementations for the unary tuple type (i.e. (T,))
• Fix an issue which could cause a panic when concurrently performing read and write transactions,
  when debug_assertions were enabled
• Optimize retain() and retain_in() to use less space in the database file
• Improve handling of some internal errors to return LockPoisoned instead of panicking

2.4.0

• Add Database::cache_stats()
• Fix open() and create() to return InvalidData when they are called on a database file
  that is not a valid redb database
• Significantly speed up restore_savepoint(). The time is takes now scales with the change delta
  since the savepoint was captured, rather than the size of the database file
• DatabaseStats::fragmented_bytes() is now more accurate

2.3.0

• Add WriteTransaction::set_two_phase_commit()
• Add WriteTransaction::set_quick_repair() which enables a faster repair mechanism at the cost of
  slower transaction commits
• Durability::Paranoid is now deprecated. Use set_two_phase_commit(true) instead
• Fix various bugs when repairing the database after an unclean shutdown. These could result in
  panics, leaked space in the database file, or database corruption

2.2.0

• Implement TableHandle for ReadOnlyTable
• Fix bug in write cache, which caused pages to be evicted randomly. Pages are now evicted based on
  how recently they have been accessed

2.1.4

• Optimize first() and last() to be almost 2x faster
• Improve in-memory cache algorithm to resolve edge cases where certain pages could become
  uncacheable under cache pressure
• Fix bug in read cache where the read cache could become disabled. This was likely to occur in
  multithreaded workloads when the read cache was smaller than the database file. This bug lead to
  5-10x performance degradations for some workloads

2.1.3

• Significant performance optimizations to compact()
• Fix some additional cases where compact() did not fully compact the database
• Fix a panic that could occur in commit() or abort() after an IO error. StorageError::PreviousIo is now returned
• Fix a potential panic that could occur when repairing the database after a crash

2.1.2

Major fixes:

• Fix leak of database space that could occur when calling restore_savepoint()
• Fix leak of database space when calling delete_multimap_table()
• Fix database corruption which could occur when restoring a savepoint. This edge case is rare,
  and could only occur if the database was less than approximately 4TiB when the savepoint was
  created, and greater than 4TiB when the savepoint was restored
• Fix edge case where a transient I/O error that occurred during transaction commit, but then did
  not reoccur when the Database was dropped, could cause database corruption

Important: If your application has called restore_savepoint(), delete_multimap_table(),
or you suspect it may have experienced a transient I/O error during transaction commit.
It is recommended that you run check_integrity() after upgrading to this version.
This will both detect corruption and clean up any leaked space.

Other changes and fixes:

• Optimize page freeing to reduce the size of the database file
• Fix several cases where check_integrity() would return Ok(false) instead of Ok(true)
• Fix some cases where compact() did not fully compact the database
• Make the metadata overhead returned by WriteTransaction::stats() more accurate
• Return StorageError::ValueTooLarge when a key-value pair exceeds a total of 3.75GiB.
  Previously, a panic would occur for key-value pairs that were approximately 4GiB.
• Downgrade several info! log messages to debug!
• Improve documentation

2.1.1

• Fix panic that occurred when calling compact() when a read transaction was in progress
• Fix ReadTransaction::close() to return Ok when it succeeds
• Performance optimizations

2.1.0

• Implement Key and Value for String
• Allow users to implement ReadableTableMetadata, ReadableTable, and ReadableMultimapTable

2.0.0

Major file format change

2.0.0 uses a new file format that optimizes len() to be constant time. This means that it is not
backwards compatible with 1.x. To upgrade, consider using a pattern like that shown in the
upgrade_v1_to_v2 test.

Other changes

• check_integrity() now returns a DatabaseError instead of a StorageError
• Table metadata methods have moved to a new ReadableTableMetadata trait
• Rename RedbKey to Key
• Rename RedbValue to Value
• Remove lifetimes from read-only tables
• Remove lifetime from WriteTransaction and ReadTransaction
• Remove drain() and drain_filter() from Table. Use retain, retain_in, extract_if or extract_from_if instead
• impl Clone for Range
• Add support for [T;N] as a Value or Key as appropriate for the type T
• Add len() and is_empty() to MultimapValue
• Add retain() and retain_in() to Table
• Add extract_if() and extract_from_if() to Table
• Add range() returning a Range with the 'static lifetime to read-only tables
• Add get() returning a range with the 'static lifetime to read-only tables
• Add close() method to ReadTransaction