The primary goal for Firebird 2.5 was to establish the basics for a new threading architecture that is almost entirely common to the Superserver, Classic and Embedded models, taking in lower level synchronization and thread safety generally. Although SQL enhancements are not a primary objective of this release, for the first time, user management becomes accessible through SQL USER statements
Administrative Enhancements:
· System audit tracing and user trace sessions via the Services API, making it possible to monitor and analyse everything going on in a database in real time
· New system role RDB$ADMIN in the ODS 11.2 database allows SYSDBA to transfer its privileges to another user on a per-database basis
· More information in the monitoring tables
· Asynchronous cancellation of connections
· Capability for ordinary users to monitor any of their own attachments as well as CURRENT_CONNECTION
Other SQL Language Additions and Enhancements:
· Regular expression support using the SIMILAR TO predicate
· ALTER COLUMN for computed columns
· Autonomous transactions within a PSQL module (stored procedure, trigger or dynamically executable PSQL block)
· Enhanced access to stored procedures in view definitions
· Optional GRANTED BY or GRANTED AS for GRANT and REVOKE statements, enabling the grantor to be a user other than the CURRENT_USER (the default).
· REVOKE ALL syntax to dispose of all privileges for a user or role at once
· Support for WHERE SOME_COL = ? OR ? IS NULL predications
· Removal of "reserved" status for all but a handful of keywords that are not reserved in the SQL standard
Data-handling Enhancements:
· New built-in functions for converting UUID CHAR(16) OCTETS strings to RFC4122-compliant format and vice versa
· Ability to pass 32-bit and 64-bit integers as hexadecimal in numeric literal and X-prefixed binary string literal formats
API Additions:
· Statements now return an SQL-2003 standard 5-alphanumeric SQLSTATE completion code
· New constant DSQL_unprepare available for use with isc_dsql_free_statement for efficient unpreparing of statements
International Language Support:
· Default COLLATE clause for CREATE DATABASE
· Ability to change the default COLLATE for a used character set
· GBAK restore switches FIX_FSS_DATA and FIX_FSS_METADATA to restore legacy databases with UNICODE_FSS data and/or metadata correctly without resorting to scripts and manual techniques
· Accent-insensitive collation for Unicode
