List of Changes
===============


2.3.1 (2012-06-28)
------------------

* Added record and list data types, support for nested records and
  segments, hierarchical output.
* Added support for locators: single record access using an array-like
  syntax.
* `top()`: retrieves the first value of a plural argument.
* Added and updated output formats: `raw`, `json`, `xml`; updated style
  for HTML output.
* `HTSQL-DJANGO`: a Django gateway to HTSQL.
* Moved all cache and configuration files to `~/.htsql/`.  Added
  `~/.htsqlrc` with default configuration parameters for `htsql-ctl shell`
  and `htsql-ctl serve`.
* Removed `htsql-ctl get` and `htsql-ctl post` routines; added
  `htsql-ctl ui`, an experimental visual HTSQL browser.
* Removed support for Python 2.5.  Currently supported are 2.6 and 2.7.
* Many other fixes and documentation updates.


2.3.0 (2012-03-07)
------------------

* Clarified HTSQL licensing: HTSQL is now released under three
  licenses: Free (AGPLv3), Permissive for use with open source
  databases, and Evaluation for use with proprietary database servers.
  See http://htsql.org/license/ for more information.
* Switched to a new version numbering scheme: each public release
  is marked by three numbers `X.Y.Z`.  Here `X.Y` are the major
  and minor version number and `Z` is a release number.  An even (odd)
  value of `Y` identifies stable (development) releases respectively.
  Thus `2.3.0` starts a new series of development  releases, which will
  conclude with the release of `2.4.0`.  Stable releases maintain
  syntax, semantics and API compatibility while development releases
  don't.
* Separated HTSQL core and database backends into different source
  packages: `HTSQL` (includes the core and SQLite backend),
  `HTSQL-PGSQL`, `HTSQL-MYSQL`, `HTSQL-ORACLE`, `HTSQL-MSSQL`.
* Extracted connection pooling to a separate addon `tweak.pool` since
  it was causing issues with SQLite and MySQL backends.
* Added a shell command `describe` to describe database metadata.
* Added a quick start guide: "HTSQL Handbook", other documentation
  updates.


2.2.1 (2011-12-15)
------------------

* Updated API for making HTSQL requests from Python application.
* Improved error messages; added suggestions for lookup errors.
* `tweak.override`: added support for global functions,
  parameterized calculations.


2.2.0 rc 1 (2011-11-22)
-----------------------

* Added ``@`` scope reset operator.
* Omit schemas when serializing table names to SQL.
* Validate configuration on startup.
* Added `tweak.override`: restricting access to specific tables
  and columns, adding database constraints, changing table, column
  and link labels, defining calculated fields.
* Added `tweak.django`: integration with Django framework.
* `tweak.meta`: improved the meta schema.
* `tweak.cors`: added `origin` parameter.
* `tweak.shell`: autocompletion by Ctrl-Space, improved layout.
* `htsql-ctl shell`: Tab-completion for commands and identifiers.
* Refactored database introspection and model graph.
* Refactored to use Unicode strings internally.
* Various build improvements: now building source, DEB and RPM packages.
* Updated documentation on installing, using and configuring HTSQL.
* Documentation on deploying on Heroku cloud platform.
* Added regression tests for addons.


2.2.0 beta 2 (2011-09-22)
-------------------------

* Rebuilt source packages to include missing resource files.


2.2.0 beta 1 (2011-09-20)
-------------------------

* Fixed silent data truncation bug on invalid values; users of SQLite
  are adviced to upgrade.
* Added support for loading application configuration from a file;
  option `-C FILE`.
* Refactored plugin architecture; added support for plugin parameters.
* Added SQLAlchemy adapter.
* Added support for statement-like functions; converted formatters
  to statements.
* Added plugin `tweak.meta`: database metadata exposed as a database.
* Added plugin `tweak.shell`: a simple web-based HTSQL editor.
* Removed plugin `tweak.schema`: functionality is implemented in
  the core.


2.1.1 final (2011-08-30)
------------------------

* General code cleanup and refactoring.
* Improved emitted SQL for projections and aggregates.
* Changed operator precedence to avoid parentheses around
  filtering and projection operators.
* Added a test data generator for HTSQL regression tests
  (thank to Yuri Yerokhin).
* Added support for hierarchical headers for `/:txt` and `/:html`
  formatters.
* Updated documentation.


2.1.0 rc 1 (2011-06-21)
-----------------------

* Added `/:tsv` formatter that generates output in tab-separated format
  (thank to Andrey Popp).
* A lot of updates to the tutorial, the reference and other
  documentation.
* Minor code updates and bug fixes.


2.1.0 beta 3 (2011-05-13)
-------------------------

* Added a fiber linking operator: `{x,y} -> T{x,y}`.
* Provide named attributes for kernel expressions and the complement
  link in a quotient scope: `(program^degree)` generates attribute
  `degree` as an alias for `*1` and `program` as an alias for `^`.
* Added in-selector definitions: `{attr := expr}` is de-sugared to
  `define(attr := expr){attr}`.
* Added `$reference` syntax for inter-scope references.
* Added flow method `fork()`: clone the last node in the flow, e.g.
  `/course?credits=max(fork().credits)`.
* Added flow methods `.filter()` and `.select()` as aliases to `?`
  and `{}` operators.
* Added method `distinct()`: `distinct(table{kernel})` produces
  a flow of unique values of `kernel` as it runs over `table`;
  it is equivalent to `table^kernel`.  `distinct()` and `^` operators
  now filter out NULL values in the kernel.
* Changed semantics of `.` and `{}` expressions: specifier (`.`)
  now allows arbitrary expressions on both sides, selector (`{}`)
  now sets the output columns in the current scope.
* Added syntax `*N`, where `N` is an integer literal, to get the value
  of the `N`-th output column.
* Added addon `tweak.cors`: append `Access-Control-Allow-Origin: *`
  to every HTTP response.
* Added addon `tweak.pgsql.inet`: basic manipulations on values
  of `INET` data type.
* Added addon `tweak.pgsql.view`: determine foreign key relationships
  for views in Postgresql.
* Use `search_path` or its analogues to choose a table when
  the table name is ambiguous.
* Optimized introspection for Oracle.
* Added option `-p` to ask for a password on startup.
* Added shell command `run filename.htsql` to load and execute
  an HTSQL query from a file.
* Many other fixes and documentation updates.


2.1.0 beta 2 (2011-03-29)
-------------------------

* Added support for `datetime` and `time` date types.
* Added support for calculated attributes, `define()` and `where()`
  macros.
* Added addon `tweak.pgsql.catalog`: configure primary and foreign keys
  for `pg_catalog.*` tables.
* Added addon `tweak.schema`: allow addressing a table in a specified schema
  as `<schema>_<table>` identifier.
* Added addon `tweak.autolimit`: add ``LIMIT`` clause to each query.
* Added addon `tweak.pgsql.timeout`: set statement timeout for each query.
* Added Jinja integration demo.
* Many minor fixes and updates.


2.1.0 beta 1 (2011-03-08)
-------------------------

* Ported to MySQL, Oracle and MS SQL Server.
* Added support for projections (`base^kernel`).


2.0.1 final (2011-02-01)
------------------------

* Merged `/:json` and `/:jsonex` formatters; use `/:jsonex` layout
  to avoid CSRF issues.
* Documentation updates.


2.0.0 rc 1 (2011-01-21)
-----------------------

* HTRAF demo is promoted to a standalone project; see
  http://bitbucket.org/prometheus/htraf.
* Added `/:jsonex` format: JSON with extra metadata.
* Documentation updates.


2.0.0 beta 5 (2010-12-14)
-------------------------

* Completed the SQLite backend.
* Completed the standard library.


2.0.0 beta 4 (2010-12-05)
-------------------------

* Refactored peep-hole optimization of the frame tree and SQL
  serialization; refined the generated SQL.
* Refactored the internal API for adding functions.
* Added new (experimental) syntax for infix function call.
* Added an "Examples" section to the documentation.
* Fixed compatibility with Python 2.5.
* Many minor bugfixes, documentation updates, etc.


2.0.0 beta 3 (2010-11-09)
-------------------------

* Refactored the translator from the term tree to the frame tree;
  added a new translation step to collapse nested frames and reduce
  SQL expressions.
* Added the HTRAF demo: use HTSQL with client-side javascript
  to define complex dashboards.
* Added the SSI demo: using HTSQL for web without giving direct access
  to the database.
* Updated the tutorial, minor bugfixes, regression test updates, etc.


2.0.0 beta 2 (2010-10-01)
-------------------------

* Refactored the translator from the expression graph to the term tree.
* Added `Content-Disposition` header to `:json` and `:csv` renderers.
* Merged the tutorial to the repository.


2.0.0 beta 1 (2010-09-21)
-------------------------

* Initial beta release.
* PostgreSQL and SQLite backends are (mostly) supported, the former
  more than the latter.
* The SQL translator needs more work, in particular, the term tree,
  the frame structure and the serializer.
* Lots of functions are either not implemented or missing a proper
  serializer, especially in the SQLite backend.
* Other areas which need more work before the final release: rendering,
  introspection, regression tests and documentation.

