# Unsupported functionalities in Babelfish
<a name="babelfish-compatibility.tsql.limitations-unsupported"></a>

In the following table and lists, you can find functionality that isn't currently supported in Babelfish. Updates to Babelfish are included in Aurora PostgreSQL versions. For more information, see the [https://docs.aws.amazon.com/AmazonRDS/latest/AuroraPostgreSQLReleaseNotes/Welcome.html](https://docs.aws.amazon.com/AmazonRDS/latest/AuroraPostgreSQLReleaseNotes/Welcome.html). 

**Topics**
+ [Functionality that isn't currently supported](#babelfish-compatibility.tsql.limitations-unsupported-table)
+ [Settings that aren't supported](#babelfish-compatibility.tsql.limitations-unsupported-list8)
+ [Commands that aren't supported](#babelfish-compatibility.tsql.limitations-unsupported-list1)
+ [Column names or attributes that aren't supported](#babelfish-compatibility.tsql.limitations-unsupported-list7)
+ [Data types that aren't supported](#babelfish-compatibility.tsql.limitations-unsupported-list9)
+ [Object types that aren't supported](#babelfish-compatibility.tsql.limitations-unsupported-list3)
+ [Functions that aren't supported](#babelfish-compatibility.tsql.limitations-unsupported-list4)
+ [Syntax that isn't supported](#babelfish-compatibility.tsql.limitations-unsupported-list5)

## Functionality that isn't currently supported
<a name="babelfish-compatibility.tsql.limitations-unsupported-table"></a>

In the table you can find information about certain functionality that isn't currently supported. 


| Functionality or syntax | Description | 
| --- | --- | 
| Assembly modules and SQL Common Language Runtime (CLR) routines  | Functionality related to assembly modules and CLR routines isn't supported. | 
| Column attributes | ROWGUIDCOL, SPARSE, FILESTREAM, and MASKED aren't supported. | 
| Contained databases | Contained databases with logins authenticated at the database level rather than at the server level aren't supported. | 
| Cross-database DDL | Performing DDL statements that reference or operate on objects across multiple databases isn't yet supported. | 
| Cursors (updatable) | Updatable cursors aren't supported. | 
| Cursors (global) | GLOBAL cursors aren't supported. | 
| Cursor (fetch behaviors) | The following cursor fetch behaviors aren't supported: FETCH PRIOR, FIRST, LAST, ABSOLUTE, abd RELATIVE | 
| Cursor-typed output parameters | Cursor-typed variables and parameters aren't supported for output parameters (an error is raised).  | 
| Cursor options | SCROLL, KEYSET, DYNAMIC, FAST\$1FORWARD, SCROLL\$1LOCKS, OPTIMISTIC, TYPE\$1WARNING, and FOR UPDATE | 
| Data encryption | Data encryption isn't supported. | 
| Data-tier applications (DAC) | Data-tier applications (DAC) import or export operations with DAC package (.dacpac) or DAC backup (.bacpac) files aren't supported. | 
| DBCC commands  | Microsoft SQL Server Database Console Commands (DBCC) aren't supported. DBCC CHECKIDENT is supported in Babelfish 3.4.0 and higher releases. | 
| DROP IF EXISTS | This syntax isn't supported for USER and SCHEMA objects. It's supported for the objects TABLE, VIEW, PROCEDURE, FUNCTION, and DATABASE. | 
| Encryption | Built-in functions and statements don't support encryption. | 
| ENCRYPT\$1CLIENT\$1CERT connections | Client certificate connections aren't supported. | 
| EXECUTE AS statement | This statement isn't supported. | 
| EXECUTE AS SELF clause | This clause isn't supported in functions, procedures, or triggers. | 
| EXECUTE AS USER clause | This clause isn't supported in functions, procedures, or triggers. | 
| Foreign key constraints referencing database name | Foreign key constraints that reference the database name aren't supported. | 
| FORMAT | User-defined types aren't supported. | 
| Function declarations with greater than 100 parameters | Function declarations that contain more than 100 parameters aren't supported. | 
| Function calls that include DEFAULT as a parameter value | DEFAULT isn't a supported parameter value for a function call. DEFAULT as a parameter value for a function call is supported from Babelfish 3.4.0 and higher releases. | 
| Functions, externally defined | External functions, including SQL CLR functions, aren't supported. | 
| Global temporary tables (tables with names that start with \$1\$1) | Global temporary tables aren't supported. | 
| Graph functionality | All SQL graph functionality isn't supported. | 
| General Extended stored procedures | System stored procedures that provide an interface from an instance of SQL Server to external programs, for various maintenance activities aren't supported. This includes `xp_cmdshell` and other system stored procedures. For more information, see [ General Extended stored procedures](https://learn.microsoft.com/en-us/sql/relational-databases/system-stored-procedures/general-extended-stored-procedures-transact-sql?view=sql-server-ver16). | 
| Identifiers (variables or parameters) with multiple leading @ characters | Identifiers that start with more than one leading `@` aren't supported. | 
| Identifiers, table or column names that contain @ or ]] characters | Table or column names that contain an `@` sign or square brackets aren't supported. | 
| Inline indexes | Inline indexes aren't supported. | 
| Invoking a procedure whose name is in a variable | Using a variable as a procedure name isn't supported. | 
| Materialized views | Materialized views aren't supported. | 
| NOT FOR REPLICATION clause | This syntax is accepted and ignored.  | 
| ODBC escape functions | ODBC escape functions aren't supported. | 
| Procedure calls that includes DEFAULT as a parameter value | DEFAULT isn't a supported parameter value. DEFAULT as a parameter value for a function call is supported from Babelfish 3.4.0 and higher releases. | 
| Procedure declarations with more than 100 parameters | Declarations with more than 100 parameters aren't supported. | 
| Procedures, externally defined | Externally defined procedures, including SQL CLR procedures, aren't supported. | 
| Procedure versioning | Procedure versioning isn't supported. | 
| Procedures WITH RECOMPILE | WITH RECOMPILE (when used in conjunction with the DECLARE and EXECUTE statements) isn't supported. | 
| Remote object references | Executing stored procedures against Babelfish linked servers isn’t supported. Four-part object names work only for reading and doesn’t work for modifying the remote table. An UPDATE can reference a remote table in the FROM clause without modifying it. For more information, see [Babelfish supports linked servers](babelfish-postgres-linkedservers.md). | 
| Row-level security | Row-level security with CREATE SECURITY POLICY and inline table-valued functions isn't supported. | 
| Service broker functionality | Service broker functionality isn't supported. | 
| SESSIONPROPERTY | Unsupported properties: ANSI\$1NULLS, ANSI\$1PADDING, ANSI\$1WARNINGS, ARITHABORT, CONCAT\$1NULL\$1YIELDS\$1NULL, and NUMERIC\$1ROUNDABORT | 
| SET LANGUAGE | This syntax isn't supported with any value other than `english` or `us_english`. | 
| SP\$1CONFIGURE | This system stored procedure isn't supported. | 
| SQL keyword SPARSE | The keyword SPARSE is accepted and ignored. | 
| Table value constructor syntax (FROM clause) | The unsupported syntax is for a derived table constructed with the FROM clause. | 
| Temporal tables | Temporal tables aren't supported. | 
| Temporary procedures aren't dropped automatically | This functionality isn't supported. | 
| Triggers, externally defined | These triggers aren't supported, including SQL Common Language Runtime (CLR). | 

## Settings that aren't supported
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The following settings aren't supported:
+ SET ANSI\$1NULL\$1DFLT\$1OFF ON
+ SET ANSI\$1NULL\$1DFLT\$1ON OFF
+ SET ANSI\$1PADDING OFF
+ SET ANSI\$1WARNINGS OFF
+ SET ARITHABORT OFF
+ SET ARITHIGNORE ON
+ SET CURSOR\$1CLOSE\$1ON\$1COMMIT ON
+ SET NUMERIC\$1ROUNDABORT ON
+ SET PARSEONLY ON (command doesn't work as expected)
+ SET FMTONLY ON (command doesn't work as expected. It suppresses only the execution of SELECT statements but not others.)

## Commands that aren't supported
<a name="babelfish-compatibility.tsql.limitations-unsupported-list1"></a>

Certain functionality for the following commands isn't supported:
+ ADD SIGNATURE
+ ALTER DATABASE, ALTER DATABASE SET
+ BACKUP/RESTORE DATABASE/LOG
+ BACPAC and DACPAC FILES RESTORE
+ CREATE, ALTER, DROP AUTHORIZATION. ALTER AUTHORIZATION is supported for database objects.
+ CREATE, ALTER, DROP AVAILABILITY GROUP
+ CREATE, ALTER, DROP BROKER PRIORITY
+ CREATE, ALTER, DROP COLUMN ENCRYPTION KEY
+ CREATE, ALTER, DROP DATABASE ENCRYPTION KEY
+ CREATE, ALTER, DROP, BACKUP CERTIFICATE
+ CREATE AGGREGATE
+ CREATE CONTRACT
+ CHECKPOINT

## Column names or attributes that aren't supported
<a name="babelfish-compatibility.tsql.limitations-unsupported-list7"></a>

The following column names aren't supported:
+ \$1IDENTITY
+ \$1ROWGUID
+ IDENTITYCOL

## Data types that aren't supported
<a name="babelfish-compatibility.tsql.limitations-unsupported-list9"></a>

The following data types aren't supported:
+ HIERARCHYID

## Object types that aren't supported
<a name="babelfish-compatibility.tsql.limitations-unsupported-list3"></a>

The following object types aren't supported:
+ COLUMN MASTER KEY
+ CREATE, ALTER EXTERNAL DATA SOURCE
+ CREATE, ALTER, DROP DATABASE AUDIT SPECIFICATION
+ CREATE, ALTER, DROP EXTERNAL LIBRARY
+ CREATE, ALTER, DROP SERVER AUDIT
+ CREATE, ALTER, DROP SERVER AUDIT SPECIFICATION
+ CREATE, ALTER, DROP, OPEN/CLOSE SYMMETRIC KEY
+ CREATE, DROP DEFAULT
+ CREDENTIAL
+ CRYPTOGRAPHIC PROVIDER
+ DIAGNOSTIC SESSION
+ Indexed views
+ SERVICE MASTER KEY
+ SYNONYM

## Functions that aren't supported
<a name="babelfish-compatibility.tsql.limitations-unsupported-list4"></a>

The following built-in functions aren't supported:

**Aggregate functions**
+ APPROX\$1COUNT\$1DISTINCT
+ CHECKSUM\$1AGG
+ GROUPING\$1ID
+ STRING\$1AGG using the WITHIN GROUP clause

**Cryptographic functions**
+ CERTENCODED function
+ CERTID function
+ CERTPROPERTY function

**Metadata functions**
+ COLUMNPROPERTY
+ TYPEPROPERTY
+ SERVERPROPERTY function – The following properties aren't supported:
  + BuildClrVersion
  + ComparisonStyle
  + ComputerNamePhysicalNetBIOS
  + HadrManagerStatus
  + InstanceDefaultDataPath
  + InstanceDefaultLogPath
  + IsClustered
  + IsHadrEnabled
  + LCID
  + NumLicenses
  + ProcessID
  + ProductBuild
  + ProductBuildType
  + ProductUpdateReference
  + ResourceLastUpdateDateTime
  + ResourceVersion
  + ServerName
  + SqlCharSet
  + SqlCharSetName
  + SqlSortOrder
  + SqlSortOrderName
  + FilestreamShareName
  + FilestreamConfiguredLevel
  + FilestreamEffectiveLevel

**Security functions**
+ CERTPRIVATEKEY
+ LOGINPROPERTY

**Statements, operators, other functions**
+ EVENTDATA function
+ GET\$1TRANSMISSION\$1STATUS
+ OPENXML

## Syntax that isn't supported
<a name="babelfish-compatibility.tsql.limitations-unsupported-list5"></a>

The following syntax isn't supported:
+ ALTER DATABASE
+ ALTER DATABASE SCOPED CONFIGURATION
+ ALTER DATABASE SCOPED CREDENTIAL
+ ALTER DATABASE SET HADR
+ ALTER INDEX
+ ALTER PARTITION FUNCTION
+ ALTER PARTITION SCHEME
+ ALTER SCHEMA
+ ALTER SERVER CONFIGURATION
+ ALTER SERVICE, BACKUP/RESTORE SERVICE MASTER KEY clause
+ BEGIN CONVERSATION TIMER
+ BEGIN DISTRIBUTED TRANSACTION
+ BEGIN DIALOG CONVERSATION
+ BULK INSERT
+ CREATE COLUMNSTORE INDEX
+ CREATE EXTERNAL FILE FORMAT
+ CREATE EXTERNAL TABLE
+ CREATE, ALTER, DROP APPLICATION ROLE
+ CREATE, ALTER, DROP ASSEMBLY
+ CREATE, ALTER, DROP ASYMMETRIC KEY
+ CREATE, ALTER, DROP CREDENTIAL
+ CREATE, ALTER, DROP CRYPTOGRAPHIC PROVIDER
+ CREATE, ALTER, DROP ENDPOINT
+ CREATE, ALTER, DROP EVENT SESSION
+ CREATE, ALTER, DROP EXTERNAL LANGUAGE
+ CREATE, ALTER, DROP EXTERNAL RESOURCE POOL
+ CREATE, ALTER, DROP FULLTEXT CATALOG
+ CREATE, ALTER, DROP FULLTEXT INDEX
+ CREATE, ALTER, DROP FULLTEXT STOPLIST
+ CREATE, ALTER, DROP MESSAGE TYPE
+ CREATE, ALTER, DROP, OPEN/CLOSE, BACKUP/RESTORE MASTER KEY
+ CREATE, ALTER, DROP QUEUE
+ CREATE, ALTER, DROP RESOURCE GOVERNOR
+ CREATE, ALTER, DROP RESOURCE POOL
+ CREATE, ALTER, DROP ROUTE
+ CREATE, ALTER, DROP SEARCH PROPERTY LIST
+ CREATE, ALTER, DROP SECURITY POLICY
+ CREATE, ALTER, DROP SELECTIVE XML INDEX clause
+ CREATE, ALTER, DROP SERVICE
+ CREATE, ALTER, DROP SPATIAL INDEX
+ CREATE, ALTER, DROP TYPE
+ CREATE, ALTER, DROP XML INDEX
+ CREATE, ALTER, DROP XML SCHEMA COLLECTION
+ CREATE/DROP RULE
+ CREATE, DROP WORKLOAD CLASSIFIER
+ CREATE, ALTER, DROP WORKLOAD GROUP
+ ALTER TRIGGER
+ CREATE TABLE... GRANT clause
+ CREATE TABLE... IDENTITY clause
+ CREATE USER – This syntax isn't supported. The PostgreSQL statement CREATE USER doesn't create a user that is equivalent to the SQL Server CREATE USER syntax. For more information, see [T-SQL differences in Babelfish](babelfish-compatibility.tsql.limitations.md).
+ DENY
+ END, MOVE CONVERSATION
+ EXECUTE with AS LOGIN or AT option
+ GET CONVERSATION GROUP
+ GROUP BY ALL clause
+ GROUP BY CUBE clause
+ GROUP BY ROLLUP clause
+ INSERT... DEFAULT VALUES
+ MERGE
+ READTEXT
+ REVERT
+ SELECT TOP... WITH TIES
+ SELECT... FOR BROWSE
+ SELECT... FOR XML AUTO
+ SELECT... FOR XML EXPLICIT
+ SELECT... FOR XML PATH
+ SEND
+ SET DATEFORMAT
+ SET DEADLOCK\$1PRIORITY
+ SET FMTONLY
+ SET FORCEPLAN
+ SET NUMERIC\$1ROUNDABORT ON
+ SET OFFSETS
+ SET REMOTE\$1PROC\$1TRANSACTIONS
+ SET SHOWPLAN\$1TEXT
+ SET SHOWPLAN\$1XML
+ SET STATISTICS
+ SET STATISTICS PROFILE
+ SET STATISTICS TIME
+ SET STATISTICS XML
+ SHUTDOWN statement
+ UPDATE STATISTICS
+ UPDATETEXT
+ Using EXECUTE to call a SQL function
+ VIEW... CHECK OPTION clause
+ VIEW... VIEW\$1METADATA clause
+ WAITFOR DELAY
+ WAITFOR TIME
+ WAITFOR, RECEIVE
+ WITH XMLNAMESPACES construct
+ WRITETEXT
+ XPATH expressions