Tarantool 2.3.1

Introduce prepared statements support and prepared statements cache (gh-2592, gh-3292). Using of prepared statements allows to eliminate overhead of transmitting a statement text over a network and parsing it each time before execution. Aside of this, it allows to acquire binding parameters and result set columns metainformation prior to actual execution of a statement. This feature is vital for implementing standard DBMS APIs, such as ODBC and JDBC.

[Breaking change] Introduce _session_setting service space as replacement for PRAGMA keyword (gh-4511). All frontends (C, Lua, SQL, binary protocol) can use this space to access or update session settings. Removed count_changes, short_column_names, sql_compound_select_limit, vdbe_addoptrace pragmas. Transformed others into _session_settings tuples.

Extend SQL result set metadata (gh-4407), In addition to the name and type fields, the collation, is_nullable, is_autoincrement, and span fields are added. These new fields are shown when the full_metadata session setting is enabled but always sent via binary protocol.

Add an ability to disable check constraints (gh-4244). Example: ALTER TABLE foo {ENABLE|DISABLE} CHECK CONSTRAINT bar;. For details of using from Lua, refer to documentation.

AUTOINCREMENT for multipart primary key (gh-4217). The auto-increment feature can be set to any INTEGER or UNSIGNED field of PRIMARY KEY using one of the two ways:

1. AUTOINCREMENT in column definition:

   CREATE TABLE t (i INT, a INT AUTOINCREMENT, PRIMARY KEY (i, a));
   CREATE TABLE t (i INT AUTOINCREMENT, a INT, PRIMARY KEY (i, a));
   

2. AUTOINCREMENT in PRIMARY KEY definition:

   CREATE TABLE t (i INT, a INT, PRIMARY KEY (i, a AUTOINCREMENT));
   CREATE TABLE t (i INT, a INT, PRIMARY KEY (i AUTOINCREMENT, a));
   

Allow to create a view from any CTE (common table expression) using WITH clause (gh-4149).

Support user-defined functions in SQL. box.schema.func.create() API has been extended and should be used to make some function available in SQL. For details on fields added, refer to the description here: (doc-879). Usage of legacy mechanismbox.internal.sql_function_create is forbidden now (gh-2200, gh-2233, gh-4113).

Scalar functions MIN/MAX are renamed to LEAST/GREATEST (gh-4405)

Introduce WITH ENGINE clause for CREATE TABLE statement (gh-4422). To allow a user to specify engine as per table option, CREATE TABLE statement has been extended with optional WITH ENGINE = <engine_name> clause. This clause comes at the end of CREATE TABLE statement. For example:

CREATE TABLE t_vinyl (id INT PRIMARY KEY) WITH ENGINE = 'vinyl';

Refer also to SQL reference documentation.

Introduce DOUBLE type (gh-3812).

Display line and position in syntax errors (gh-2611).

Make constraint names unique within a table (gh-3503). The SQL standard requires PRIMARY KEY, UNIQUE, FOREIGN KEY and CHECK constraints to have the unique name within a table. Now Tarantool/SQL follows this requirement. Please refer to (doc-1053).

Optimization: a tuple already stores a map of offsets of indexed values. After the change, when a field after an indexed field is accessed, the tuple is decoded from the indexed field rather then from beginning (gh-4267).

[Breaking change] Drop rows_per_wal option of box.cfg() in favor of wal_max_size (gh-3762).

Decimals can now be stored in spaces. The corresponding field type is introduced: decimal. Decimal values are also allowed in the scalar, any, and number fields. Decimal values can be indexed (gh-4333). Also refer to documentation on

• data types
• <space_object>:create_index()

Add support for decimals in update operations (gh-4413). tuple:update() and <space_object>:update() now support decimal operands for arithmetic operations (‘+’ and ‘-’). The syntax is as usual, for example:

tarantool> d = box.tuple.new(decimal.new('1'))
---
...
tarantool> d:update{{'+', 1, decimal.new('0.5')}}
---
- [1.5]
...

Insertion (‘!’) and assignment (‘=’) are also supported. See also the full description of the update() function in documentation.

Allow to encode/decode decimals to MsgPack and to encode to YAML and JSON. Part of (gh-4333); 485439e3; documentation: (doc-992).

Introduce field name and JSON path updates (gh-1261).

Example of update by a field name: box.space.test:update({{'=', 'foo', 42}}).

JSON path update allows to change a value that is nested inside an array or a map. It provides convenient syntax (that is also available for connectors), consumes less space in WAL than replace, and is faster than replaces written in Lua. Example: box.space.test:update({{'=', 'foo.bar[1]', 42}}). Please refer to documentation here: (doc-1051).

Introduce double field type. Part of (gh-3812). Though is not very usable in Lua, this new field type has been added in box as a base for the SQL DOUBLE type.

vinyl: don’t pin index for iterator lifetime (prerequisite for snapshot iterators). 02da82ea

vinyl: don’t exempt dropped indexes from dump and compaction (prerequisite for snapshot iterators). d7387ec9