I plan to look at some of the upcoming 10.00.xC5 features later this month, but should first mention the xC3 and xC4 features (note 10.00.xC2 was not a general release). The following list is mainly borrowed from one of ScottishPoet's recent comp.databases.informix newsgroup posts:
New Features in Version 10.00.xC3
- ANSI-joins in distributed queriesTransaction support for XA-compliant external data sourcesMQ DataBlade moduleNew DBCREATE_PERMISSION configuration parameter to restrict the abilityto create databasesNew secure default directory for the DUMPDIR configuration parameterTable-level restore for smart large object columnsAES cipher support for network encryptionNew Enterprise Replication commands to show statistics informationClient SDK included in Dynamic Server installation processReturning subsets of query results as collection-derived tablesOrdering subsets of query results in collection-derived tablesJ/Foundation upgrade to JRE 1.4.2New default directory for ADTPATH configuration parameterNew UNSECURE_ONSTAT configuration parameter
- to this I should add support for multi-threaded multiple listener threads on Windows (catching up with the UNIX 10.00.UC1 feature), and Tivoli TDP for Informix support on Windows.
New features in IDS 10.00.xC4
- TRUNCATE table supportEnterprise Replication direct synchronizationEnterprise Replication consistency checkingEnhanced support for IPv6Secure local connectionsSecure DataBlade module pathsParallel backup and restore is more efficientDB-Access stops a process after the first errorInformix Interface for TSM supports HP-UX (Itanium)New default value for IFX_EXTEND_ROLE configuration parameter
Some of these, particularly TRUNCATE TABLE can have a huge performance impact. There are more performance improvements on the way in xC5 too, along with security and Windows-specific features.