4.0.3 is a stable 4.0 version.
Changelist:

• SQL editor: context tooltips (F2) + database help system integration
• Database data transfer wizard was fixed (tables/columns mapping)
• Drivers download dialog was fixed
• Query manager view UI improved (columns sorting)
• Maven repositories switched to SSL versions
• Exasol: statements execution performance was improved
• Exasol: LUA scripts, functions
• Oracle 8 and 9i support has been improved
• Oracle: sequence manager was added (create/drop/alter)
• HSQLDB extension was added (views, procedures source, sequences)
• Hive: table data viewer/exporter fix. Array data type support.
• Hive Spark driver configuration added
• DB2 for z/OS: error message extraction config
• A lot of minor UI fixes/improvements
• All national localizations were disabled

This is second hotfix version.
Version 4.0 had too many new features and some of them wasn’t well tested. Hopefully 4.0.2 will resolve most of these problems.
Brief changelist:

• Transaction monitor errors fixed
• CLOB value editor fixed
• MySQL: table create fixed
• MySQL: column position change feature
• MySQL: column charset/collation edit support
• Oracle: standalone procedures navigation fixed
• Oracle 8: metadata reading fixed
• PostgreSQL: database switch was fixed
• DB2 iSeries driver update
• Dark theme fixes
• Secured Maven repositories support
• Connection folders creation was improved
• Connection properties dialog was fixed (performance + datasource-specific settings)
• Misc minor UI bugs were fixed

This is a hotfix version:

• Oracle connector was fixed
• DB2 for z/OS connector was fixed
• ODBC connector was fixed
• Commit/Rollback command enablement was fixed
• Solaris version build was fixed
• A few minor bugfixes

Changelist:

• Migration on Eclipse 4.6 platform:
  • DBeaver now requires Java 8
  • Support of HighDPI monitor
  • SQL editor zoom in/out function
  • Many UI fixes in GTK mode (CPU usage)
• Transaction monitor
• Pending transactions monitor dialog
• Commit/Rollback commands are enabled only if transaction is active
• SQL editor: performance fixes (CPU usage in idle mode)
• SQL editor: tabs switch shortcuts added
• SQL editor: memory leaks fixed (multiple result tabs)
• SQL completion: quoted identifiers completion has been fixed
• Results view: custom coloring fixed (multiple color settings for single column)
• Results view: attributes hide/show fixed (visibility change doesn’t require results refresh)
• Query manager view: rows coloring was fixed
• Data export: execute external process on finish
• CSV export: NULL value rendering configuration
• Create index: ability to set column ordering
• Connection keep alive now reopens failed connections
• Status bar: shows current time zone and locale
• Connection editor: connection folder settings save was fixed
• SSH tunnel config: ask for password if password wasn’t saved in connection settings
• BLOB value rendering was fixed
• HSQLDB: embedded database shutdown fix
• MySQL: SSL support has been improved (certificate private key support, Google Cloud support)
• Oracle: PL/SQL packages navigation was improved (navigate from procedures and from SQL editor)
• Oracle: fix of metadata reading for version <= 8
• PostgreSQL: numeric columns scale/precision are now editable
• PostgreSQL: case-insensitive autocompletion was fixed
• PostgreSQL: new tables/columns comments save was fixed
• SQLite: data editor was improved (SQLite synamic data type system support)
• SQLite: read and edit of triggers and sequences
• SQLite: native tables/views/triggers DDL
• SQLite: tables rename support
• Many minor bug fixes

This is a hotfix version. It fixes performance issues in 3.8.4 and also adds a few minor improvements.
Changelist:

• SQL editor performance fix (auto-completion)
• Export from SQL query fix
• Results advanced copy/paste: quote complex cell values
• Results viewer: value view panel refresh fixed
• Foreign key dialog: schema selector added
• Metadata editor: copy/paste in search control fixed
• Metadata editor: columns configuration dialog fixed
• Generate SQL action fixed
• PostgreSQL: schema selector fixed
• A few minor UI fixes

Changelist:

• Resultsets refresh UI was improved
• SQL editor: connection selector was redesigned
• SQL editor: auto-indent/completion was fixed
• Use virtual keys in generated SQL
• Generate SQL UPDATE for resultsets
• Connection editor save was fixed
• DBeaver identification config added
• Maven repositories configuration UI has been improved
• Preferences pages were reorganized
• German localization (thanks to @Sargul)
• PostgreSQL: table/role permissions viewer was added
• PostgreSQL: new column create dialog added
• PostgreSQL: disable BEGIN/END blocks processing
• Exasol: auto-completion was fixed
• MS SQL: DDL generation was fixed
• Cassandra: NULL values read/write fixed
• Data export: JSON format was fixed
• Many minor UI fixes/improvements

I hope that this is the last 3.x version.
4.0 release is planned at the end of February.

• Metadata viewer: columns are configurable
• Navigator filters toggle command
• SSH tunnel auth (password/public key) fix
• SSH tunnel invalidate fix
• SQL templates formatting fixed
• SQL script execution fixed (blank lines)
• SQL editor: empty files delete fix
• Data viewer UI improved (column description in header)
• Date editor: include combo-box editor was fixed
• Connection wizard UI improved
• Keep connection user name in secured storage
• Connection properties edit/save fixed
• MySQL: zero date/time value support
• MySQL: drop index fix
• PostgreSQL: procedure parameter names reading fix
• PostgreSQL: sequence properties reading fix
• PostgreSQL: CHECK constraints support
• Teradata: JSON editor
• Exasol: maven driver added
• Eclipse Marketplace support added (EE version)
• Many minor UI fixes

• Hierarchical connection folders support added
• New folders browser was added
• Object (table, schema, etc) editor activation (after restart) was improved
• SSH tunnel invalidation fix
• SSH keep-alive config was fixed
• Connections copy/paste was fixed
• Metadata search results UI fixed
• Data export wizard was fixed (bad performance for long SQL queries)
• Results viewer: total row count action added
• Results editor: drop-down editor fixed, activation on key-down fixed
• PostgreSQL: JSON support (value copy, array view) fixed
• PostgreSQL: extra keywords & data types highlighting
• Firebird: SQL delimiter redefine support added
• Oracle: procedures/packages
• check compile status on save
• Oracle: PL/SQL blocks execution was fixed
• DB2: session manager UI was fixed
• DB2: tools (runstats, reorg, etc) UI was fixed
• Teradata: JSON support
• Exasol: views/tables descriptions, misc fixes
• Exasol: now uses Maven repository for driver download
• Cassandra: new rows edit was fixed
• Cassandra: date/time values edit fixed
• Misc UI fixes

DBeaver 3.8.1 is mostly a bug fix version. Brief changelist:

• Object editor: many fixes in properties editor/refresh
• Results editor: row data refresh after insert/update
• ERD: refresh action was fixed
• SQL queries execution was fixed (multiple statements, params binding)
• SQL completion was fixed
• Generic: auto-increment columns creation support (H2, Derby, Teradata, MSSQL)
• H2: new database extension (supports views source, sequences)
• MySQL: dump/restore wizard fixed
• PostgreSQL: local client home configuration fixed
• PostgreSQL: triggers properties improved
• Oracle: triggers caching fixed (performance)
• Cassandra: SSH tunnel support added
• MongoDB: support of replica servers
• Secure passwords storage support (EE)
• Misc minor UI fixes

• SQL editor tabs management was redesigned
• Object editor UI was redesigned
• Basic icons were updated
• Results viewer: web hyperlinks support, URL transformations, web pages viewer
• PostgreSQL: database dump/restore support was added (pg_dump/pg_restore)
• PostgreSQL: admin tools added (analyze, vacuum, truncate)
• PostgreSQL: trigger properties were fixed
• PostgreSQL: view triggers support
• MariaDB: local client detection fixed
• Cassandra: query trace panel added
• Oracle: tablespace management was added
• Oracle: SQL error position detection improved
• Exasol: high speed load/unload to csv
• Exasol: Virtual schema support
• MacOS: product info (plist) was fixed
• SQL Editor: dynamic parameters binding fixed (+dialog redesign)
• SQL Editor: status toolbar was fixed/improved (warning list)
• SQL completion fix (extra options in preferences)
• SQL generator fix (DDL for complex objects like packages)
• Many minor UI fixes