Caché Release Notes and Upgrade Checklist Archive
New and Enhanced Features for Caché 5.1
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Welcome and thank you for using Caché!

This chapter provides an overview of the new and improved features in Caché 5.1.
See the Major New Features section for a description of the important new features and enhancements included in this release.
If you are new to Caché, you can refer to the Getting Started page which contains a variety of links to documentation organized by topic.
Upgrading and Installation
If you are upgrading existing applications and databases from prior versions, please read the Caché 5.1 Upgrade Checklist and the Upgrading chapter of the Caché Installation Guide.
For information on installing Caché, refer to the following sources:
Major New Features
Caché 5.1 introduces a significant number of new features as well as enhancements to existing features. These features are focused on:
The new features are summarized here. For additional details, refer to the cited chapters or guides.
Caché Advanced Security
A host of new capabilities have been added to give Caché the most advanced security of any mainstream database.
System Management Portal
A new integrated system management interface, built with CSP, replaces Control Panel, Explorer, and SQL Manager. This removes the requirement for a Windows PC in order to manage Caché and, because no Caché client software is required, eliminates potential client/server version mismatch issues and simplifies management of multiple versions of Caché from a single device.
System Improvements
Caché system improvements include many new or enhanced classes and methods, plus major enhancements such as nested rollback and the ability to map class packages to namespaces.
ObjectScript Language Improvements
The ObjectScript language now provides significantly improved runtime error reporting. Many other enhancements have been introduced, including the following items:
New Language Bindings
With this release, Caché introduces new Perl and Python bindings, as well as an improved version of the Caché ActiveX binding.
Object Improvements
The Caché 5.1 Class Library provides many new features and major enhancements.
SQL Improvements
Caché SQL support includes many new or enhanced features, including the following items:
Connectivity Improvements
Caché 5.1 introduces many new options for network connectivity.
Caché Advanced Security
With version 5.1, InterSystems introduces Caché Advanced Security. This release of Caché contains a host of new capabilities that provide the most advanced security of any mainstream database. Caché Advanced Security provides a simple, unified security architecture that offers the following advantages:
See the Caché Security Administration Guide for detailed information on Caché Advanced Security.
Key Features
Here are a few of the more important new security features offered in Cache 5.1:
Security Advisor
To assist system managers in securing a Caché system, Caché includes a Security Advisor. This is a Web page that shows current security-related system configuration information, recommends changes or areas for review, and provides links into other system management Web pages to make recommended changes.
Caché 5.1 contains the initial version of the Security Advisor. Its function and range will expand in future versions. It is accessed through the System Management Portal at [Home] > [Security Management] > [Security Advisor].
InterSystems strongly recommends a review and resolution of the issues raised by the Security Advisor before allowing a secured system to attain production status.
Low-level Security Interfaces
System administrators can exercise low-level control over the security of Caché systems through two character-oriented interfaces:
Common Criteria Security Certification
Security certification is becoming an increasingly frequent requirement for government purchases, and is more and more requested for private sector purchases. Because of this, InterSystems has had Caché certified according to the Common Criteria standard. Specifically, effective February 15, 2007, Caché received certification according to the Common Criteria standard (EAL 3).
The Common Criteria provides a set of common security standards for a wide number of nations in North America, Europe, and the Far East. It provides an assurance scale from 1 to 4, where a product's rating indicates the rigor of testing to which it has been subjected; commercially available products are rated from 1 (least rigorous testing) to 4 (most rigorous). Caché is currently under consideration for a level-3 rating. Such a rating indicates that Caché can effectively serve as part of a highly secure operational environment.
Caché Advanced Security Concepts
Caché Advanced Security is based on authentication, authorization, and auditing:
Authentication: Establishing Identity
Authentication is how you prove to Caché that you are who you say you are. Without trustworthy authentication, authorization mechanisms are moot — one user can impersonate another and then take advantage of the fraudulently obtained privileges.
The authentication mechanisms available depend on how you are accessing Caché. Caché has a number of available authentication mechanisms:
Authorization: Controlling User Access
Once a user is authenticated, the next security-related question to answer is what that person is allowed to use, view, or alter. Authorization manages the relationships of users and assets such as databases, Caché services like ODBC access, and user-created applications.
In the most basic authorization model, there are all possible assets, a list of users, and all the relationships between the first group and the second.
Auditing: Knowing What Happened
Auditing provides a verifiable and trustworthy trail of actions related to the system. Auditing serves multiple security functions:
The auditing facility automatically logs certain system events; it also allows you to enable logging for other system events, as well as site-defined application events. All audited events are placed in a tamper-resistant log file. Authorized users can then create reports based on this audit log, using tools that are part of Caché. Because the audit log can contain sensitive information (such as regarding positive or negative values for medical tests), running an audit report itself generates an entry for the audit log. The included Caché tools support report creation, archiving the audit log, and other tasks.
System Management Portal
Caché 5.1 now uses a browser-based interface, the System Management Portal, for system management. This new interface subsumes the functions previously distributed among Explorer, SQL Manager, Configuration Manager, and Control Panel functions of the Windows Caché Cube. In 5.1, these have been removed from the Cube.
An advantage of this approach is that it is no longer a requirement that Caché be installed on the system you use to manage an installation. Remote management of systems over the web, subject to access control established for the site, is now much easier. No Caché client software is required, simplifying management of multiple versions of Caché from a single device. Cross-release compatibility issues are minimized because both the data and its formatting information come directly from the system being managed.
See Using the System Management Portal for a detailed description of the new interface.
System Improvements
New Caché 5.1 system features and enhancements:
New Features:
Enhanced Features:
Nested Rollbacks
This version of Caché introduces multiple transaction levels , which make it possible to roll back part of a transaction without losing all work completed to that point. When nested TSTARTs are used, this enhancement enables the innermost TSTART to be rolled back, without rolling back the entire open transaction. When two TSTARTs are issued without an intervening COMMIT or TROLLBACK, the transaction level ($TLEVEL) is incremented by 1 (limited to a maximum of 255). When a TCOMMIT or TROLLBACK 1 is issued, the transaction level is decremented by 1. When an unqualified TROLLBACK is issued, the transaction level is decremented to 0, and the entire transaction is rolled back.
Transaction commands now work as follows:
Caché SQL now includes standard SQL commands that take advantage of nested rollbacks (see New SAVEPOINT Features).
Namespace Mapping for Class Packages
Namespace mapping has been extended with the ability to map class packages from a database to one or more namespaces, just as routines and globals are mapped. Automatic namespace mapping is provided for system classes. All the schemas that begin with '%' from %sys are mapped to all namespaces automatically. These mappings allow the user to access SQL Table, View, Procedures, and classes across multiple namespaces. For example, assume a class %Test that has the following query:
Select field1 From %Test
Without mapping, attempting to inherit from this class in a user namespace would result in error: "Table %Test not found". With mapping, the class will compile successfully in any namespace.
For detailed information, see Configuring Data in the Caché System Administration Guide.
New Method $SYSTEM.Util.CleanDeadJobs()
New class method $SYSTEM.Util.CleanDeadJobs() is used to roll back a dead job's open transaction (if any) and clean up the dead job's Process Table (pidtab) slot so it can be re-used.
New Class $SYSTEM.Monitor.Line
New class $SYSTEM.Monitor.Line is a programmer API for the line-by-line monitor (^%MONLBL). It allows integration with Studio, and is also generally useful as a programmable alternative to ^%MONLBL. For details, see the Programming Interface section in the MONLBL chapter of the Caché Monitoring Guide.
New Method $System.Device.GetNullDevice()
New class method $System.Device.GetNullDevice() returns the name of the null device appropriate for the current operating system type (/dev/null for UNIX®, _NLA0 for OpenVMS, //./nul for Windows). It facilitates development of applications that reference the Null device, and provides an OS-independent method for obtaining the name of the Null Device.
New Optional Argument for $ZF(-2)
Function $ZF(-2) now has an optional fifth argument that specifies whether or not the spawned process ID should be stored in $ZCHILD. For example:
s rc=$zf(-2,"program","","",1) 
s childpid=$ZCHILD 
If the new argument is zero or not specified then $ZCHILD is unchanged, otherwise $ZCHILD is set to the spawned process ID when it is successfully spawned.
Option to Filter Records before Dejournaling on a Shadow
To filter journal records before they get dejournaled on a shadow, set the global node ^SYS("shdwcli",shdw_id,"filter") to the name of the filter routine (without the leading "^"). The input parameters of the filter routine are:
In compatible mode shadowing, the pid and timestamp parameters passed to the filter routine always have the value "". The filter routine should return 0 if the record should be skipped; otherwise the record will be dejournaled by the shadow. For example:
^SYS("shdwcli","MyShadow","filter")="MyShadowFilter"
MyShadowFilter(pid, dir, glo, type, addr, time) ; 
;skip X* globals 
If $EXTRACT($qs(glo,0))="X" q 0 
Set Msg = pid
Set Msg = Msg _ "," _ dir
Set Msg = Msg _ "," _ glo
Set Msg = Msg _ "," _ type
Set Msg = Msg _ "," _ addr
Set Msg = Msg _ "," _ time
Do ##class(%Library.Device).Broadcast("",Msg) 

q 1
Callin Enhancements
The Callin include files ccallin.h and mcallin.h have been enhanced to merge common functionality and provide greater flexibility for building user-defined C and C++ Callin modules. Defines have been added to make building user Callin modules as independent of interface details as possible. Two features control the selection of interfaces:
#define ZF_DLL
If ZF_DLL is not defined, the Callin module is built for linking with the Caché engine. If it is defined, the module is built as a dynamic shared library using Callback and invoked through the Callout facility. This is the same define employed by cdzf.h.
#define CACHE_UNICODE
If CACHE_UNICODE is not defined, string handling functions and arguments are treated as 8-bit characters. If defined, strings are treated as 16-bit Unicode. String handling functions are available with the "A" suffix, meaning 8-bit (or ASCII), the "W" suffix, meaning 16-bit Unicode (or wide), and no suffix. In the last case the function resolves to either the "A" or "W" suffix according to the definition of CACHE_UNICODE.
New functionality has been implemented to permit NLS translation using the CacheCvtInW() and CacheCvtOutW() functions for Unicode Callin to 8-bit Caché. They will now convert data within the 8-bit character set range of the Caché engine, instead of reporting an "unimplemented" error. CacheCvtInA() and CacheCvtOutA() functions for 8-bit Callin to Unicode Caché are not currently implemented.
You can further refine 8-bit argument prototypes with the new macro USE_CALLIN_CHAR, which declares them as (char *) rather than (unsigned char *).
64K Routine Buffer Support
It is now possible to run with routine sizes up to 64K, by changing the Memory/RoutineBufSize value on the [Home] > [Configuration] > [Advanced Settings] page of the Management Portal from 32 to 64. The default and minimum value is still 32 (32K), but now values can be specified from 33..64 (rounded to the nearest 2K increment). Routines or class descriptors greater than 32K will be stored as two global values, the first chunk in ^rOBJ(<routine name>) as currently, and the second chunk in ^rOBJ(<routine name>,0).
CVENDIAN Enhancements
The cvendian database endian conversion utility has been enhanced to allow for positive identification of the desired endian orientation, or to optionally just inform the current endian orientation with no conversion. The command syntax is:
cvendian [-option] file1 [file2 ... file8]
where option is one of the following:
The options may be shortened to their initial letter. If this is a conversion request, and the database already is of the specified endian orientation, a warning message is displayed and no further processing is done. Prior cvendian call formats remain supported.
Object Improvements
New Caché 5.1 object features and enhancements:
Object Enhancements
New Option to Index on Computed Fields
An index definition can now reference properties defined as CALCULATED and SQLCOMPUTED. The property value calculation must be deterministic, always returning the same value for a given set of parameters. For example, it would be a mistake to use a function such as $Horolog, which returns different values depending on when it is called. Indexing on a property whose computation is nondeterministic will result in an index that is not properly maintained.
To support this option, properties defined as SQLCOMPUTED are now computed in Caché Objects. A new class method, Compute, is called by the property's Get method. The Compute method generates a return value by scanning SQLCOMPUTECODE for field references and converting those references to property or literal values. If the property also has SQLCOMPUTEONCHANGE, the Compute method is called whenever the property is changed.
New Object Synchronization
This new feature enables Caché to synchronize objects between databases. All object filing events (insert, update and delete) for journaled classes are automatically tracked. Object synchronization utilities provide methods to export the journaled object data and synchronize it with other databases. Applications with no access to the original database can then resolve references to the synchronized objects.
A new class, %SYNC.SyncSetObject, supplies methods to externalize an object and apply it to the target database. All references to persistent objects from the object being externalized are converted to GUID (Globally Unique Identifier) values. The GUID values are used to look up the corresponding object on import.
Another class, %SYNC.SyncSet, implements methods to manage the set of objects being synchronized. A 'synchronization set' is a set of externalized object values which guarantee that all object references can be resolved, either because the referenced object is in the same sync set, or because it already exists in the target database.
New Studio Extension Classes and Source Control Hooks
This release enhances the flexibility of Caché Studio by introducing the %Studio.Extension classes, which provide mechanisms for custom menus and user defined data entry. The %Studio.SourceControl classes now provide enhanced source control hooks, allowing customized checkout and checkin to a source control system.
When the user performs an action in Studio that may require user interaction with the server (for example, attempting to edit a document that is in source control but is not checked out), Studio now calls the UserAction method.
UserAction (Type, Name, InternalName, SelectedText, .Action, .Target, .Msg)
Type options are:
Name is the menu item name if Type is a menu item, otherwise Name indicates one of the following options:
InternalName is the name of the document this action is concerned with.
SelectedText contains any selected text in the document that has focus.
Action returns an action that Studio should perform:
You can define custom menus for Studio to display. Studio obtains the menus when it first connects to a namespace by running two queries, MainMenus and MenuItems. MainMenus returns the list of top level menu names. After this top level menu is selected, MenuItems is used to return the list of items on a specific menu. MainMenus can be either a regular menu or a context submenu that is added to all the context menus. The MenuItems query is passed the current document name and any selected text in case you wish to vary the menu based on these arguments.
By default, the source control class inherits these queries from %Studio.Extension.Base, where they are defined as SQL queries against prebuilt tables. To load data into these tables, define an XData block called Menu in your source control class. When the source control class is compiled, this data is loaded and used automatically. Queries defined in the source control subclass can be changed or completely customized. When data is being returned from the MenuItems query, each menu name will generate a call to an OnMenuItem method in the source control class, where you may disable/enable this menu item. This allows simple modification of the menus without having to write a custom query.
New Stream Syntax
The class hierarchy for current stream classes has been changed so that %Stream.Object is the top class. This change does not alter stream runtime behavior.
In prior versions of Caché, it was necessary to define a stream property as type = %Stream, with a collection value of binarystream or characterstream. Now a stream property is defined by specifying the actual stream class as the type, and the collection keyword values of binarystream and characterstream are no longer used. A stream class is declared with a classtype = stream. This declaration is automatic for any class that extends a new class, %Stream.Object. For backward compatibility, the classes %Library.GlobalCharacterStream, %Library.GlobalBinaryStream, %Library.FileCharacterStream, and %Library.FileBinaryStream have been converted to use the new representation, and are to be used for all existing stream data.
For more detailed information, see the Streams chapter in Using Caché Objects.
New %SwizzleObject Class
A new class, %SwizzleObject, is now the primary (and only) superclass of both %Persistent and %SerialObject. The purpose of the new class is to define the swizzling interface and implement the parts of that interface that are common to both %Persistent and %SerialObject.
See the %Library.SwizzleObject class documentation for more detailed information.
Extended POPSPEC Syntax
The syntax of POPSPEC has been extended to allow an SQL table name and an SQL column name to be specified. When they are specified, the Populate() method constructs a dynamic query to return the distinct column values from the table. The requested number of values will then be randomly selected from the distinct column values and placed in a value set. The property will then be assigned values randomly from the resulting value set.
See The Caché Data Population Utility for more detailed information.
Performance Improvements for Relationships
The in-memory performance of relationships has been significantly improved by using additional in-memory indices to keep track of oref's and oid of items already in the relationship. Previously, when a new item was inserted into the relationship (either using the Insert method, or indirectly via the Relate method) it would scan the entire relationship to avoid inserting a duplicate item. By keeping an index of the oref's and oid's in the relationship, the cost of checking for duplication items is kept very low even for large numbers of items.
Partition memory used is lower, speed is significantly faster (94x in the second insert of 1000 items) and %Save time is faster. When measured with a small number of items in the relationship, there was no measurable slowdown in performance associated with the upkeep of the additional in-memory indices.
Enhanced VisM OCX
This release contains a new version of the Caché Direct control (VISM.OCX) that features enhancements such as security upgrades, support for multithreading, and improved error handling.
Language Improvements
New Caché 5.1 ObjectScript features and enhancements:
New Language Bindings:
Improved Runtime Error Reporting
Many runtime errors now report additional information. For instance, an "<UNDEFINED>" error will now report the name of the undefined variable.
Error information is stored in the system variable $ZERROR, which now returns more information than before. For example, when a routine attempts to use a variable that has not been defined, $ZERROR now includes the name of the undefined variable. Whereas in previous versions of Caché the value of $ZERROR might look like this:
<UNDEFINED>zMethodName^Pkg.Class.1
in version 5.1, it looks generically like this (adding " *someinfo"):
<ERRCODE>Tag^Routine+line *someinfo
A consequence of this change is that error handling routines that made assumptions about the format of the string in $ZERROR may now require redesign to work as before. For further information, see the Cache Conversion Guide, and the $ZERROR special variable in the Caché ObjectScript Reference.
New $FACTOR Function
$FACTOR is a new ObjectScript function for 5.1 that converts a numeric value to a bitstring. Its primary use is for the creation of bitslice indices. For further information, see the $FACTOR function in the Caché ObjectScript Reference.
New $LISTNEXT, $LISTTOSTRING, and $LISTFROMSTRING Functions
Caché 5.1 adds three new functions for processing list structures: $ListNext, $ListToString and $ListFromString.
$ListNext(list, ptr, val) allows extremely rapid traversing of a list structure (up to 400x faster than doing a loop with $LIST).
Before the first call to $ListNext, ptr should be initialized to 0. After each call, ptr will contain the position of the next element in list (0 if the end of the list was reached), and val will contain the value of the element at that position (undefined if there was no value at that position). $ListNext will return 1 if it found another list element, or 0 if it is at the end of the list.
$ListToString(list[,delim]) takes list, and returns the elements as a string separated by delim (default ",").
$ListFromString(string[,delim]) takes string, delimited by delim (default ","), and returns the pieces as a list.
For further information, see the $LISTNEXT, $LISTTOSTRING, or $LISTFROMSTRING function in the Caché ObjectScript Reference.
New $ROLES and $USERNAME Special Variables
At Caché 5.1, the $ROLES special variable lists the security roles currently assigned to the user. The $USERNAME special variable list the user name for the current process. For further information, see the $ROLES, $USERNAME special variables in the Caché ObjectScript Reference.
New $ZUTIL(62,1) Function
The $ZUTIL(62,1) function performs syntax checking on a line of Caché ObjectScript code. It returns the character position of the error and the text of an error message. For further information, see the $ZUTIL(62,1) function in the Caché ObjectScript Reference.
New $ZUTIL(69) System Configuration Functions
Caché 5.1 documents the following additional system-wide configuration functions: $ZUTIL(69,19), $ZUTIL(69,21), $ZUTIL(69,31), $ZUTIL(69,35), $ZUTIL(69,37), $ZUTIL(69,44), $ZUTIL(69,49), and $ZUTIL(69,60).
Caché 5.1 also supports the new $ZUTIL(69,63) and $ZUTIL(68,63) functions that control whether a lowercase “e” should be interpreted as an exponent symbol.
For further information, see the $ZUTIL(69) functions in the Caché ObjectScript Reference.
New $ZUTIL(158) Function
The $ZUTIL(158) function can be used to return the number of installed printers and the pathname of a specified printer. For further information, see the $ZUTIL(158) function in the Caché ObjectScript Reference.
New $ZUTIL(186) Function
The $ZUTIL(186) function can be used to specify the information displayed as part of the Terminal prompt. For further information, see the $ZUTIL(186) function in the Caché ObjectScript Reference.
New $ZUTIL(193) Function
The $ZUTIL(193) function inter-converts Coordinated Universal Time and local time values. For further information, see the $ZUTIL(193) function in the Caché ObjectScript Reference.
New Error Trapping Syntax
This version of Caché implements a special syntax that allows an error trap to pass control up the program stack to a previously established error trap. The syntax is ZTRAP $ZERROR. This command will pop entries off the program stack until a level is found with an error trap. Then that error trap will be executed with $ZERROR and $ECODE unchanged.
This command replaces the two commands ZQUIT 1 GOTO @$ZTRAP, which did not work in new-style procedures. This new command syntax can be used in both procedures and old-style subroutines. The old style of passing control up to a previous error trap will continue to work in old-style subroutines. If a ZQUIT command is issued in a procedure, it will now result in a <COMMAND> error.
The ZQUIT command is obsolete as of 5.1, and should not be used for new programming.
More Efficient Code Generation
The CacheBasic compiler now uses an improved algorithm that generates significantly smaller and faster code.
Pattern-Match “E” Adapted For Unicode
In prior version of Caché, the options used with the pattern-match operator(s) assumed 8–bit characters. This caused the “E” pattern (match every character) to fail when Unicode characters above $CHAR(255) were present in the string.
In Caché 5.1, the “E” pattern matches all characters.
Faster MERGE Command
The MERGE command is now much faster and more efficient when merging two local variables.
New Perl and Python Bindings
The Caché Perl and Python bindings provide a simple, direct way to manipulate Caché objects from within Perl or Python applications. They allow binding applications to establish a connection to a database on Caché, create and open objects in the database, manipulate object properties, save objects, run methods on objects, and run queries. All Caché datatypes are supported.
See Using Perl with Caché and Using Python with Caché for more detailed information.
Improved ActiveX Bindings
Caché 5.1 includes a new version of the Caché ActiveX binding, CacheActiveX.dll. Internally this new version uses the Caché C++ binding to get object-level access to a Caché server. Using this new binding provides the following benefits:
While every attempt has been made to make this new DLL functionally compatible with the older CacheObject.dll it is not 100% binary compatible.
To preserve complete compatibility with existing applications, Caché installs two ActiveX bindings; the newer CacheActiveX.dll as well as the original CacheObject.dll. By default, existing applications will continue to use the original CacheObject.dll. If you wish to use the newer binding you have to modify your existing application to reference this new DLL and test that your application performs as expected.
SQL Improvements
New Caché 5.1 SQL features and enhancements:
New Features
SQL Enhancements
New SQL/XML Support Functions
5.1 implements a collection of new built-in SQL functions for transforming “flat” relational queries into hierarchical XML documents. Application programs that need to generate HTML, or that need to export data in XML format, now have a general and portable interface that has wide industry support (ANSI/ISO SQL-2003 standard).
The following SQL/XML functions are available:
For more detailed information see XMLELEMENT, XMLAGG, XMLCONCAT and XMLFOREST in the Caché SQL Reference.
New SAVEPOINT Features
With version 5.1, Caché introduces multiple transaction levels (see Nested Rollbacks), which make it possible to roll back part of a transaction without losing all work completed to that point. Caché SQL now offers the following standard SQL commands that take advantage of this ability:
For more detailed information see SAVEPOINT in the Caché SQL Reference.
CREATE TABLE: New IDENTITY Keyword
Caché SQL now supports the ability to define a column with a system-generated numeric value in a CREATE TABLE statement. An IDENTITY column is an exact non-negative integer column whose values are system-generated, and may not be assigned by the user in either INSERT or UPDATE statements. It may, however, be viewed using SELECT *. The syntax is:
CREATE TABLE <tablename> ( 
   [ other-table-elements , ] 
   <columnname> [ <datatype> ] IDENTITY
   [ UNIQUE | NULL | NOT NULL | 
      DEFAULT [(]<default-spec>[)] | 
      [COLLATE] <sqlcollation> | 
      %DESCRIPTION <literal> 
   ] 
[ , other-table-elements ] 
) 
An IDENTITY column is always data type INTEGER with unique non-null values. You can specify a datatype and constraints, but these are ignored by Caché.
This syntax is consistent with Microsoft SQL Server and Sybase syntax.
For more detailed information, see CREATE TABLE in the Caché SQL Reference.
DROP VIEW: New CASCADE Keyword
Caché SQL now supports the ability to cascade the deletion of a view to also delete any view that references that view. The new keywords are CASCADE and RESTRICT. The RESTRICT keyword is the default and is the same as prior DROP VIEW behavior.
For more detailed information, see DROP VIEW in the Caché SQL Reference.
INSERT: New DEFAULT VALUES Clause
Caché SQL now supports the ability to use default field values when inserting a row into a table. The syntax is:
INSERT INTO <tablename> DEFAULT VALUES 
The statement will insert a single row into the table. Each field that has a default value will have the value assigned to the column. Fields without default values will be NULL for the row.
For more detailed information, see INSERT in the Caché SQL Reference.
New RowId Counter Validation Option
A new configuration option now makes it possible to validate new system-assigned ID values. The option is activated by setting ^%SYS("dbms","validate system-assigned id") to 1. Although such validation is not normally necessary, it is possible that the ID could be invalid if the user has modified the value manually, or if objects are inserted into the table without using the object or SQL filer. Other system recovery errors could also allow this condition to exist (bad recovery of a journal file, disk failure, etc.).
When this option is enabled, the table compiler will generate a uniqueness check on insert for the Id value. If validation fails, SQLCODE=-119, will be returned to the caller and a message will be written to the console log. After writing a message to the Console.log file and before returning from the filer, the user-defined routine ^%ZOIDERROR will be called. It is important to review the console log when this error is reported.
When this error is reported, it will be necessary to bring the ID counter back into sync with the data. Each failure will cause the system ID counter to be incremented, so it is possible that the problem will correct itself over time. At the point the error is reported it is not necessarily true that the counter is wrong, since the data itself may be incorrect. It is the responsibility of the user to determine how the counter became invalid.
New Query Optimizer Plan Verification
Regression tests based on TestSQLScript now have an easy way to verify query plan stability. Defining the class parameter SHOWPLAN=1 in %UnitTest.TestSQLScript will cause the query optimizer plan to be written to an output file.
JDBC 3.0 Support
Cache 5.1 supports JDK 1.4 and JDBC 3.0. All required features and most optional features are supported.
GRANT and REVOKE Command Changes
Due to the extensive improvements to Caché security at 5.1, the SQL GRANT and REVOKE commands no longer support the following syntactical forms:
The GRANT and REVOKE command support the following additional options:
For more detailed information, see GRANT and REVOKE in the Caché SQL Reference.
CREATE USER Command Changes
At 5.1, issuing a CREATE USER does not automatically assign any roles or privileges to the user, regardless of the privileges held by the creator. Privileges and roles must be assigned to a new user using the GRANT command.
For more detailed information, see CREATE USER in the Caché SQL Reference.
Subquery Flattening
In many cases the SQL engine will now attempt to “flatten” certain types of SQL queries. That is, a query will be internally converted into an equivalent form that does not contain a subquery. In many cases, it is easier for the SQL optimizer to recognize this equivalent form, and a better execution plan is generated.
Enhanced Locking Behavior for Foreign Key References
Locking behavior during table filing has been changed in the following ways:
READONLY Tables and Fields
Prior to this version of Caché, trying to INSERT, UPDATE, or DELETE into a ReadOnly table would not result in an error until the statement was executed. In this version, an SQLCODE=-115 error will be raised during compilation.
When a property is defined as ReadOnly, the field in the corresponding SQL table is also now defined as ReadOnly. READONLY fields may only be defined via an initialexpression or SQL Compute code; they may never be explicitly insert or updated via SQL statements. Any attempt to INSERT or UPDATE a value for the field (even a NULL value) will result in an SQLCODE=-138 error ("Cannot INSERT/UPDATE a value for a ReadOnly field").
SQLCODE Changes
The following SQLCODE error codes have been added for 5.1:
The following obsolete SQLCODE values have been removed:
SQLCODE -340, -341, -342, -343, -344, -345, -346, -347
For a complete list of SQLCODE values, refer to the SQLCODE Values and Error Messages chapter of the Caché Error Reference.
Support for %%CLASSNAMEQ and %%TABLENAME
Caché SQL now supports {%%CLASSNAMEQ} and {%%TABLENAME} references in class definition SQL specific COS code in the following locations:
{%%CLASSNAMEQ} (not case-sensitive) will translate to the quoted string for the name of the class which projected the SQL table definition.
{%%TABLENAME} (not case-sensitive) will translate to the quoted string for the qualified name of the table
For example, assume the following trigger in the class User.Person:
Trigger AfterInsert1 [ Event = INSERT, Order = 1, Time = AFTER ] 
{ 
Set ^Audit("table",{%%TABLENAME},$j,"AFTER INSERT TRIGGER")=1 
Set ^Audit("class",{%%CLASSNAMEQ},$j,"AFTER INSERT TRIGGER")=1 
} 
If User.Employee extends User.Person, the following SQL trigger code will be pulled as an AFTER INSERT trigger in the SQLUSER.EMPLOYEE table:
Set ^Audit("table","SQLUser.Employee",$j,"AFTER INSERT TRIGGER")=1 
Set ^Audit("class","User.Employee",$j,"AFTER INSERT TRIGGER")=1 
CREATE BITMAP INDEX Support for Oracle Import Compatibility
When loading an Oracle SQL script file through $SYSTEM.SQL.DDLImport() or $SYSTEM.SQL.Oracle(), Caché SQL now recognizes the CREATE BITMAP INDEX statement.
Extended Support for Milliseconds
Caché SQL now supports fractional seconds in all date/time functions. The DATEADD, DATEDIFF, DATENAME, and DATEPART functions now support a datepart of "ms" or "milliseconds". The ODBC Scalar functions {fn TIMESTAMPADD()} and {fn TIMESTAMPDIFF()} now support the SQL_TSI_FRAC_SECOND parameter.
See DATEPART in the Caché SQL Reference for more detailed information.
Date and Time Function Enhancements
Connectivity Improvements
New Caché 5.1 connectivity features and enhancements:
New ECP Cluster Support
Enterprise Cache Protocol is now supported in shared disk cluster configurations with OpenVMS and Tru64 UNIX®.
Differences between ECP cluster and failover cluster:
Features
InterSystems strongly recommends the use of ECP for clustered systems. ECP represents a significant advance over predecessor networking approaches such as DCP. Customers currently using DCP for communications among members of a cluster will see improvements in performance, reliability, availability, and error recovery by converting to ECP.
New SNMP Support
To enable monitoring of Caché by a variety of systems management tools and frameworks, support for the Simple Network Management Protocol (SNMP) has been added. The %SYSTEM.MonitorTools.SNMP class allows for control of SNMP agents and functions. This class contains methods to start and stop the Caché SNMP agent, as well as the CreateMIB() method which generates a custom MIB file based on an application description in the Monitor Framework.
For details, see Using SNMP to Monitor Caché in the Caché Monitoring Guide.
New LDAP Client
Programmatic access to LDAP (Lightweight Directory Access Protocol) servers has been added. See the %Net.LDAP.Client.Session class documentation for details.
New Mac OS X server support
This version of Caché now installs and executes natively on Mac OS X 10.3. The installation kit is a standard ".dmg" distribution produced by PackageMaker.
Support has been added for Mac OS X as a server plus the following client components:
A native Objective-C binding is also available.