New

• Removed LiteDB.Studio (moved to another repo)
• Added back LiteDB.Shell (netcore tool) for SQL commands
• Implement Shrink
• Create MAP and FILTER expression methods:
  • MAP(children => age)
  • FILTER(items => price > 100)
• Add expression methods: REMOVE_KEYS, OID_CREATIONDATE, TO_LOCAL, TO_UTC, DISTINCT, UNION, EXCEPT, TOP
• Added support for custom ctor in classes to BsonDocument mapper
  • public People(string name) { this.Name = name; }
• Remove LINQ GroupBy<T, K> (must use BsonExpression)
• Added transaction monitor to manage how memory LiteDB pages will use in transactions
• Implement first SharedConnection to keep database closed after each command (can be used for multiple processes in same machine)
• BugFixes (see commit log)

Here is the new alpha version of LiteDB v5. It's an alpha version, so that means it's not ready for production yet! The API may change and data format can also change before final release. But we would be very pleased if you could test the new version and give feedback or report any issues that you stumble upon.

New major version

• Complete new engine - WAL (Write Ahead Log)
• MultiVersion Concurrency Control (Snapshots & Checkpoint)
• Full transaction support
• Support for multiple readers without locking
• Write lock on collection-level instead of database-level
• Doubled the amount of indexes per collection, now up to 32 indexes per collection
• New FileStorage with custom Id type
• New BsonExpressions: transform, filter, map, reduce, ..
• New Query Pipe inside engine
• Simple upgrade of existing LiteDB v4 databases (use upgrade=true in connection string)
• New Linq visitor (with support for more expressions)
• New fluent Query
• And more than one year of hard working!!

SQL Support

• New SQL language support - very similar to ANSI SQL
• Select, Insert, Update, Delete, Create Index, Drop Index, Drop Collection, Explain
• Support for GroupBy, Having, Limit, Offset, OrderBy, Includes, ...
• System collections (get information about the database)
• Support to system function (import/export CSV/JSON)

LiteDB Studio

• New GUI for Windows
• Multi tab, multi thread, multi transactions
• Interact with your database and collections using SQL statements

Know issues

• Missing Shrink method and UserVersion property
• Curretly not completely compatible with LinqKit PredicateBuilder
• Only single process for now (with multi thread support) - no multi process yet

• Fix IncludeAll missing method

• Added IncludeAll method
• Added LENGTH method expression

Bugfix

• Index DateTime will use LocalTime #921

Bugfix

• Fix DateTime UTC in index Min/Max
• Initial size with encryption #929
• Better message when using OSX about file lock
• Remove System.Threading reference for netstandard
• Fix collection sequence in shrink #899
• Fix shrink lock page #892
• Fix NextIndex dictionary

New

• Add "flush" option in connection string (support direct in disk flush after write operation)

New

• New expression ITEMS method (convert array into IEnumerable)
• New expression ALL method (return true only if all conditions are true) - ALL($.Items[*].Price > 0) = true

Bugfix

• BSON deserialization bug on hi concurrency access
• Performance issue about flush on HDD disk #836
• Remove missing reference in Include #831

News 4.1

• Add UTC deserialization support (use utc=true on connection string)
• New FindSort operation with paging (experimental)
• New TempDiskService for temporary database
• New shell detail help help <command>
• Bugfix initial data-size
• Bugfix logger ctor #776 @parabola949
• Expressions:
  • Add support to Document syntax: new BsonExpression("{_id: 1, name: 'John'}")
  • Add support to Array syntax: new BsonExpression("[1, 'two', false]")
  • Add document function: EXTEND()
  • Add cast functions: INT(), DOUBLE(), STRING(), DATE() ...
  • Add date functions: DATEADD(), DATEDIFF(), YEAR(), MONTH(), DAY()

LiteDB v4 released

New Features

• Add support to NETStandard 2.0 (with support to Shared mode)
• New document Expression parser/executor - see Expression Wiki
• Support index creation with expressions

col.EnsureIndex(x => x.Name, "LOWER($.Name)");
col.EnsureIndex("GrandTotal", "SUM($.Items[*].Qtd * $.Items[*].Price)");

• Query with Include it´s supported in Engine level with ANY nested includes

col.Include(x => x.Users)
   .Include(x => x.Users[0].Address)
   .Include(x => x.Users[0].Address.City)
   .Find(...)

• Support complex Linq queries using LinqQuery compiler (works as linq to object)
  • col.Find(x => x.Name == "John" && x.Items.Length.ToString().EndsWith == "0")
• Better execution plan (with debug info) in multi query statements
• No more external journal file - use same datafile to store temporary data
• Fixed concurrency problems (keeps thread/process safe)
• Convert Query.And to Query.Between when possible
• Add support to Query.Between open/close interval
• Same datafile from LiteDB v3 (no upgrade needed)

Shell

• New UPDATE/SELECT statements in shell
• Shell commands parser/executor are back into LiteDB.dll
• Better shell error messages in parser with position in error
• Print query execution plan in debug (Seek([Age] > 10) and Filter([Name] startsWith "John")) (preparing to new visual LiteDB database management tool)

Break changes

• Remove transactions
• Remove auto-id register function for custom type
• Remove index definitions on mapper (fluent/attribute)
• Remove auto create index on query execution. If the index is not found do full scan search (use EnsureIndex on initialize database)

• Add KEYS, MOD expression function
• Add support for ( and ) inside expressions
• Improve expression reader/parser
• Bugfix: return _id when insert
• Minor bugfixes