Oracle® TimesTen In-Memory Database

1.1 Changes for Release 11.2.1.8.0 from Release 11.2.1.7.1

1.2 Changes for Release 11.2.1.7.1 from Release 11.2.1.7.0

• A problem with the log reader has been fixed. This problem could cause replicated databases to go out of sync. It also could cause TimesTen to return error 16211: "No matching v* value found for table". (BugDB 10226676)

• This release supports cross-release replication and migration from a database that does not have manual parallel replication enabled to a database that does have parallel replication enabled. (BugDB 10232988)

  See "TimesTen to TimesTen Replication" for more information about cross-release migration and manual parallel replication.

  The following is an example of migrating a database to a manually configured parallel replication scheme.

  1. Start with two TimesTen databases from a release earlier than 11.2.1.6.0. Consider two databases, rep1 and rep2, with the following scheme:

     CREATE REPLICATION r 
     ELEMENT e DATASTORE MASTER rep1 SUBSCRIBER rep2 
     ELEMENT e2 DATASTORE MASTER rep2 SUBSCRIBER rep1 
     STORE rep1 PORT 12345 
     STORE rep2 PORT 12346;
     

  2. Set the replication state to pause on rep1.

     ttRepAdmin -state pause rep1
     

  3. Stop replication on database rep2:

     ttAdmin -repStop rep2
     

  4. Create a migration file and destroy database rep2:

     ttMigrate -c -repUpgrade rep2 rep2.mig ttDestroy rep2
     

  5. Set environment to 11.2.1.7.1.

  6. Edit rep2 DSNs to include ReplicationApplyOrdering=1, ReplicationParallelism=n

     At this stage no parallelism is in use on database rep2, but you have configured it and the database will have parallel replication once it is communicating with another parallel replication database.

     Bidirectional replication is possible between databases rep1 and rep2 after you perform these steps. An ALTER TABLE operation on database rep1 will be applied to database rep2. However, an ALTER TABLE operation on a database that has parallel replication enabled is not permitted. The ALTER TABLE operation on database rep2 fails.

  7. On TimesTen 11.2.1.7.1 restore database rep2 with parallel replication from the migration file:

     ttMigrate -r rep2 rep2.mig
     

  8. Start replication on database rep2:

     ttAdmin -repstart rep2
     

  9. Set the replication state on rep1 to start.

     ttRepAdmin -state start rep1
     

  10. Apply a similar procedure to database rep1 to bring both databases up to the latest TimesTen version and to enable parallel replication between both databases. You can use ttRepAdmin -duplicate to upgrade rep1 instead of using ttMigrate.

      Bidirectional replication is possible between databases rep1 and rep2 should now be possible and user defined replication through multiple tracks can be used.

  Once you have enabled parallel replication between two databases, it is not possible to downgrade one side to a non-parallel version and replicate to the parallel-enabled side.

• A read performance issue caused by an internal instrumentation of the JDBC driver has been fixed. (BugDB 10236300)

• A scaling issue with frequent updates to the SYS.SYSTEMSTATS table was fixed. (BugDB 10271481)

• A problem has been fixed in which a TTClasses application that calls the overloaded TTCmd method setParam(char*), setParam(void*, int) or setParam(SQLWCHAR*, int) with a parameter whose length is greater than 4000 bytes long could encounter a memory fault, memory corruption or incorrect result. (BugDB 10275365)

• In a bidirectional replication scheme that includes sequences, the memory usage of the replication agent on the "passive" database could appear to grow unbounded when the other database was updated. This problem has been fixed. (BugDB 10282229)

• In previous releases, a replication agent could encounter an assertion failure: EOLCNT == LOGC->USEDSTRANDCNT. This problem has been fixed. (Bug 10332533)

1.3 Changes for Release 11.2.1.7.0 from Release 11.2.1.6.6

The behaviorchanges.txt file is no longer included in the installation directory. Behavior changes are included in this document.

5.1 Deprecated items in Releease 11.2.1.8.0

The MonInterval Clusterware attribute

5.2 Deprecated items in Release 11.2.1.7.0

The ScriptInstallDir Clusterware attribute

5.3 Removed items in Release 11.2.1.4.0

The -lsn option of the ttXactAdmin utility

5.4 Deprecated items in Release 11.2.1.1.0

• LogBuffSize attribute. Use LogBufMB instead. The units have changed from kilobytes to megabytes.

• Including sequence values in a CREATE VIEW statement is deprecated.

5.5 Removed items in Release 11.2.1.1.0

• Authenticate attribute

• It is not possible to set the Logging attribute to 0. The only possible value is 1.

• Built-in procedures: ttCommitLSN, ttLogBufPrint, ttuser, ttUserPrivileges

• The -at and -af options of the ttXactLog utility have been removed.

5.6 Deprecated items in Release 11.2.1.0.0

• The GroupRestrict and Authenticate attributes are deprecated. They are scheduled to be removed in a later release.

5.7 Removed items in Release 11.2.1.0.0

• SELECT FOR UPDATE ON ORACLE SQL statement

• DURATION clause in CREATE CACHE GROUP and ALTER CACHE GROUP SQL statements

• The ttCacheAgingMemoryThresholdSet and ttCacheAgingIntervalSet built-in procedures

• The TransparentLoad attribute and the TT_TRANSPARENT_LOAD ODBC option have been removed. Use dynamic cache groups instead.

• The OracleID attribute has been removed. Use OracleNetServiceName instead.

• The ExclAccess attribute has been removed.

• The Cache Administrator (web-based user interface) has been removed.

• TimesTen no longer supports these platforms: AIX 5.2, HP-UX 11i v1, RedHat 3, Solaris 8 (Sparc), Solaris 10 x86 32-bit, SUSE Linux 9 and TRU 64.

• TimesTen no longer supports Oracle9i or Oracle 10.1.0.x.

• TimesTen no longer supports JDK 1.4.x on all platforms. Also, classes15.jar and classes16.jar have been removed.

• TimesTen no longer supports the gcc 3.2.3 compiler, Visual C++ 6.0, Visual Studio .NET 2002 and Sun Studio 10.

6.1 Installing and uninstalling TimesTen

• TimesTen is not supported with these Oracle Linux 5 kernels: Oracle Linux 5 GA with virtualization option (2.6.18-8.el5xen), Oracle Linux 5 Update 1 with virtualization option (2.6.18-53.el5xen), Oracle Linux 5 Update 2 with virtualization option (2.6.18-92.el5xen).

  TimesTen is supported with these Oracle Linux 5 kernels: Oracle Linux 5 kernel version 2.6.18* without the xen suffix and without the virtualization option, Oracle Linux 5 Update 4 with virtualization option (2.6.18-164.el5xen), Oracle Linux 5 Update 5 with virtualization option (2.6.18-194.el5xen).

  The uname -r Linux command displays the Linux kernel version.

• If you are installing Oracle TimesTen on a new 64-bit RedHat Linux system, you may find that it is not enabled for 32-bit applications. According to the Redhat Enterprise Linux installation guide: 'Users of AMD64, Intel(R) EM64T, and Itanium systems who want support for developing or running 32-bit applications are encouraged to select the Compatibility Arch Support and Compatibility Arch Development Support packages to install architecture specific support for their systems.'

• On Windows 64-bit systems, TimesTen 32-bit and 64-bit instances cannot coexist on the same system.

• On Windows systems, you cannot perform a modified or incremental installation. For example, if you originally installed only the Oracle TimesTen Client and later wanted to install the Oracle TimesTen Data Manager, you need to uninstall TimesTen and reinstall all of the components you wish to have on your system.

• When uninstalling TimesTen on Windows, the oci.dll file shipped with the TimesTen installation sometimes cannot be removed because it is in use by a process that is not part of TimesTen.

• To run TimesTen 32-bit on AIX, you must install the appropriate fix or higher mentioned at:

  http://www-01.ibm.com/support/docview.wss?uid=isg1fixinfo105065
  

  Without this operating system patch, core dumps or other serious problems may occur when running TimesTen.

  The root IBM APAR is: IZ10231: R27 OVERWRITTEN AFTER DLSYM EXECUTION APPLIES TO AIX 5300-06.

  See http://www-01.ibm.com/support/docview.wss?uid=isg1IZ10231.

• For releases 11.2.1.5.0 and later, you must relink applications on AIX after installing TimesTen. Failure to do so results in an application execution error similar to the following:

  Could not load program _application_:
  Dependent module _tt_inst_dir_/lib/libtten.a(libtten.so) could not be loaded.
  File _tt_inst_dir_/lib/libtten.a is not an archive or the file could not be read properly.
  System error: Exec format error
  

• When re-installing TimesTen on UNIX, existing sys.odbc.ini and sys.ttconnect.ini files are optionally saved as sys.odbc.ini.old and sys.ttconnect.ini.old files and new demo files are installed. In this case, you must manually merge any additional DSNs that may have been defined after reinstalling.

6.2 Upgrading TimesTen

• The ttMigrate utility cannot migrate foreign key dependencies between objects owned by different users to TimesTen release 11.2.1.1.0 and later without a workaround. To work around this problem, first restore the parent tables. Then grant the owner of the child tables the appropriate REFERENCES privileges on its parent tables. Finally, restore the child tables.

• The ttMigrate utility cannot migrate materialized views to TimesTen release 11.2.1.1.0 and later without a workaround. To work around this problem, first restore the detail tables referenced by the materialized view. Then grant the owner of the materialized view SELECT privileges on every detail table. Finally, restore the materialized view.

6.3 Log Files

• Support log files do not rotate properly on Windows operating systems. When the MaxSupportLogFiles limit is reached, new log files should overwrite old files in the order they were created. On Windows systems, new log files randomly overwrite the old files.

6.4 PL/SQL

• PL/SQL is not supported on Solaris x86 and Linux Itanium systems.

• PLSQL_CODE_TYPE=NATIVE can be specified, but it is implemented as INTERPRETED.

• JRockit on 32-bit Linux allocates a default heap that is 50 percent of available physical memory up to 1 gigabyte. Users of JRockit on 32-bit platforms may need to choose a value for PLSQL_MEMORY_ADDRESS other than the default (10000000). Consider values such as B0000000, which ensures that the PL/SQL shared memory is not part of the JRockit heap.

• Using q' (quoting syntax) is not supported.

• The EXECUTE IMMEDIATE statement cannot be used to execute a PL/SQL anonymous block.

• UTL_FILE access is limited to a temporary directory located in install_dir/plsql/utl_file_temp. The instance administrator can grant access to UTL_FILE to specific database users. Users can reference the directory using UTL_FILE if and only if they provide the string 'UTL_FILE_TEMP' for the location parameter string.

• With Java 6 on 32-bit AIX, connections to a PL/SQL-enabled database using the TimesTen direct driver may fail because of a memory address conflict between the Java memory segment and the TimesTen PL/SQL memory segment. Such a failure is reported as error TT8517:

  SQLException: [TimesTen][TimesTen 11.2.1.4.0 ODBC Driver][TimesTen]TT8517:
  Cannot attach PL/SQL shared memory; 
  PLSQL_MEMORY_ADDRESS not valid or already in use
  

  The conflict can be resolved by specifying a smaller Java memory maximum size using the -Xmx option to java or the IBM_JAVA_OPTIONS environment variable. For example: java -Xmx64M. Use java -verbose:sizes to see the current default Java memory size.

  An alternative solution is to explicitly set the TimesTen PLSQL_MEMORY_ADDRESS connection attribute to a value that does not conflict with the Java segment. Potential good values for PLSQL_MEMORY_ADDRESS may include 0xe0000000 and 0xa0000000, depending on the environment and other factors. See the AIX documentation for a complete discussion of how Java uses memory on AIX.

6.5 TimesTen OCI support

See "Oracle Call Interface Support" in Oracle TimesTen In-Memory Database C Developer's Guide for detailed information about known problems and limitations.

• TimesTen OCI is not supported on Solaris x86 or Linux Itanium systems.

• Certain PL/SQL blocks with OUT parameters, when executed against TimesTen OCI, can generate an ORA-12899 error when the data coming back from the PL/SQL block overflows the bound output buffer. This occurs only when the parameters are bound with the UTF16 character set.

• If NLS_LANG is set to a value that is not supported by TimesTen, spurious errors such as "Cannot connect" may result.

• When an INSERT or UPDATE statement is executed which has an array of structures bound as parameters (using OCIBindArrayofStruct), the first execution of the statement succeeds. Subsequent executions may result in a numeric overflow error, a uniqueness constraint violation or a truncation error.

6.6 TimesTen support for Oracle Pro*C/C++ Precompiler

See "TimesTen Support for Oracle Pro*C/C++ Precompiler" in Oracle TimesTen In-Memory Database C Developer's Guide for detailed information about known problems and limitations.

• TimesTen Pro*C/C++ is not supported on Solaris x86 or Linux Itanium systems.

• The windows link line for a Pro*C application that uses SQLLIB functions should include both OCI.LIB and ORASQL11.LIB. The correct order is OCI.LIB first, then ORASQL11.LIB. Reversing the order can lead to the SQLLIB functions not working.

• When a variable is declared as long long on 32-bit Solaris and 32-bit HP-UX platforms, Pro*C generates its size as long.

• When compiling a Pro*C/C++ demo, this message may appear: "System default option values taken from: install_dir/ttoracle_home/instantclient_11_1/precomp/admin/pcscfg.cfg." The path name may be incorrect.

6.7 JDBC

• On HPUX 11 systems, 32-bit JDBC client and direct drivers cannot coexist in one JVM due to some problems with loading shared libraries.

• If a JDBC application running in a time zone that has Daylight Savings Time selects a non-existent time using ResultSet.getTimestamp(), it gets a time that is an hour behind. For example, in Pacific Standard Time, on the day when the time changes from Standard to Daylight Savings Time, the time between 2:00 a.m. and 2:59 a.m. does not exist. So, if a JDBC application running in Standard Time selects a value of '2002-04-07 02:00:00' using getTimestamp() it gets '2002-04-07 01:00:00'.

• JDBC applications may see some memory leak if JDBC objects are not properly closed and have not been garbage collected before the corresponding Connection is closed.

6.8 JMS/XLA

• TimesTen does not generate an XLA (Transaction Log API) record for CREATE MATERIALIZED VIEW LOG operations. See Oracle TimesTen In-Memory Database C Developer's Guide for other details about XLA.

• JMS/XLA depends on the Oracle GDK for internationalization support. TimesTen distributions include a version of orai18n.jar in install_dir/lib that JMS/XLA is tested against. JMS/XLA may work with other versions of orai18n.jar but those versions are not supported. See Oracle TimesTen In-Memory Database Java Developer's Guide for other details.

• To achieve the highest throughput, JMS/XLA applications running on Linux should follow performance guidelines presented in the section entitled "Handling high event rates" in Oracle TimesTen In-Memory Database Java Developer's Guide to work around these issues.

6.9 Cache grid

• If an insert of a new instance in one grid node does not propagate to the Oracle database before a dynamic load operation for the same instance is executed on a child table in another grid node, then the dynamic load operation results in "0 rows found".

6.10 IMDB Cache

• When trying to create a global cache group, the database can become invalidated if there are more than 15 errors in the cache group definition. This only happens when connecting to the 11.2.0.1 Oracle Server. The workaround is to use Oracle Server release 10g, 11gR1, or an 11gR2 release higher than 11.2.0.1.0.

• There is a known issue (BugDB 9359437) that during a FLUSH CACHE GROUP operation, TimesTen may lock the tables and rows in the cache group tables. This can cause blocking or a deadlock if your application attempts to update the rows concurrently.

• If an application performs more than one UNLOAD BY ID operation on a cache group, there is potential for a deadlock with the autorefresh transaction executed by the cache agent. The deadlock occurs only if those same rows are being updated on the Oracle database at the same time.

• CREATE, ALTER and DROP CACHE GROUP statements are not supported in serializable isolation mode.

• If DDL tracking is enabled on the Oracle database, destroying a database that has cache groups may result in the DDL trigger on a cached table not being dropped from the Oracle database. The user must manually drop each of these triggers using the DROP TRIGGER statement on the Oracle database. The DDL trigger name of a table with an Oracle object with identifier X is TT_X_DDL_T. The object identifier of an Oracle table can be retrieved from the V$ALL_OBJECTS view on the Oracle database.

• For autorefresh cache groups, after a transaction that executes several DML operations on an Oracle base table (for example in a bulk insert), we recommend that you coalesce the autorefresh log table index (the logseq column in the change table). Use ALTER INDEX index_name COALESCE.

• Oracle server bug 7512227 causes TimesTen autorefresh to miss inserts and updates on the Oracle base table. Autorefresh does not miss deletes. The Oracle Server bug applies to Oracle 10g releases 10.2.0.3 and above but does not occur in Oracle Database 11g. There are two solutions:

  • Set the CURSOR_SHARING Oracle server parameter to EXACT.

  • Install the appropriate Oracle patch for Oracle release 10.2.0.3 or above.

  See Metalink document 793948.1.

• Caching an Oracle synonym that is owned by a different user results in error 5140: Could not find owner.synonym in Oracle. May not have privileges. The workarounds are:

  • The owner of the synonym can create the cache group.

  • Create a new private synonym that points to the original synonym and then create the cache group. The user who owns the cache group that caches the synonym must match the owner of the synonym.

• For IMDB Cache to work correctly, the value returned by the hostname command and the uname -n command (UUCP address) must be the same. If hostname and uname -n return different values, IMDB Cache may report constraint violation failures on Oracle. Alternatively, you can use uname -s to make sure that the Internet and the UUCP addresses are the same.

• Set SQLNET.SEND_TIMEOUT and SQLNET.RCV_TIMEOUT to a value large enough to avoid unnecessary timeouts during normal operations. For example, setting each parameter to 100 seconds forces any communication call from TimesTen to Oracle to time out within 200 seconds.

• With Passthrough=3, if a JDBC application calls setTimestamp() on a passthrough statement when binding more than one field, the session NLS_TIMESTAMP_FORMAT is lost. You can work around this issue by changing the SQL statement to use TO_TIMESTAMP(?, 'syyyy-mm-dd hh24:mi:ss.ff9') and TO_DATE(?,'syyyy-mm-dd hh24:mi:ss').

• The description of the PassThrough general connection attribute in Oracle TimesTen In-Memory Database Reference should include this statement: "Passthrough execution of DDL statements does not result in commits on TimesTen."

• Nullable foreign keys can result in rows without a corresponding parent row. The rows may become stale and may not be refreshed properly through a manual refresh or autorefresh operation. They may not get removed through unload or aging operations, and they may not be updated on Oracle through a flush statement.

• When using IMDB Cache, the following JDBC methods are not supported with Oracle pass-through modes 1 through 3: PreparedStatement.setAsciiStream(), PreparedStatement.setUnicodeStream(), PreparedStatement.setBinaryStream(), PreparedStatement.setCharacterStream().

6.11 TimesTen integration with Oracle Clusterware

• When you perform one of these actions:

  • Answer the prompt for which host should be designated as the host for the active database.

  • Enter the ttCWAdmin -create command.

  You receive the message:

  "Warning!! Data store on host(s) host list may be destroyed in Order to be duplicated from active after the roll out. Please back up this data store manually if necessary, before executing ttCWAdmin -start".

  If a database with the specified DSN exists on the host for the standby database, the old database will be destroyed and replaced with the database that is created by the ttCWAdmin -create command.

  The warning has no meaning if there is no database with the specified DSN on the standby host.

• The TimesTen integration with Oracle Clusterware is not available on these platforms: Solaris 32-bit SPARC, HP-UX PA-RISC, HP-UX Itanium 32-bit, AIX 32-bit, Linux Itanium and Windows 64-bit.

• Spurious internal errors in the logs may be generated during TimesTen Clusterware operations. These errors are benign. Run ttCWAdmin -status to verify the status of the system.

6.12 TimesTen to TimesTen Replication

• Cross-release replication and migration from a database that does not have manual parallel replication enabled to a database that does have manual parallel replication enabled does not work when one of the databases is release 11.2.1.6.x or 11.2.1.7.x. Migration from a database without manual parallel replication to a database with manual parallel replication is possible for the following release combinations:

  • Before 11.2.1.6.0 to 11.2.1.6.0

  • Before 11.2.1.6.0 to 11.2.1.8.0 or later

  • 11.2.1.8.0 or later to 11.2.1.8.0 or later

  To migrate from an 11.2.1.6.x or 11.2.1.7.x database without manual parallel replication to a database with manual parallel replication, upgrade each database to 11.2.1.8.0 without manual parallel replication first.

• Replication for an altered table can fail if the replication agent is stopped immediately after the ALTER TABLE statement has been issued and the agent has not advanced past the end of the ALTER TABLE transaction. This problem can occur regardless of return service policy. If you need to stop the replication agent after an ALTER TABLE transaction, issue a ttRepSubscriberWait call to ensure that the replication agent restart point has advanced beyond the alter table operation.

• TimesTen can return error message TT6003 when using master-subscriber two-safe replication and autorefresh cache groups. This can occur, specifically, if the first replicated two-safe transaction has either a LOAD CACHE GROUP or an ALTER CACHE GROUP SET AUTOREFRESH STATE operation on an autorefresh cache group. To work around this problem, either avoid doing a LOAD or ALTER on the first replication transaction or use active standby pair replication.

• Access to the NEXTVAL SQL function of a sequence is not supported in a query on a standby node of an active standby pair.

• If the first operation in a two-safe user session is an ALTER TABLE operation, the ALTER TABLE is not replicated. The workaround is to do some other operation on the table in the same session before altering the table.

• Under very rare circumstances, it is possible for a pair of replicated detail tables and their corresponding materialized view to diverge. This divergence can only happen if the materialized view satisfies both of the following conditions:

  • The view definition has two or more predicates.

  • One of the predicates contains an expression that can generate an exception such as numeric overflow, division by zero or string truncation.

  Replicating an update to a detail table can cause divergence if differences in the order of predicate evaluation on the two databases cause a predicate to be evaluated and generate an exception only on the receiving database. The store then rejects the update, resulting in divergence of the detail table and the materialized view. To prevent such divergence, users should avoid replicating materialized views that have predicates that can generate exceptions during expression evaluation. The SQL CAST operator can be used in some cases to avoid arithmetic overflow.

• Foreign key and uniqueness constraints cannot be checked at the statement level if ttXlaApply is used to implement replication.

• For replication to work efficiently, it must be able to quickly translate host names of peers into IP addresses. For this to happen efficiently on Windows, make sure that a Windows system is set up to query either a valid WINS server or a valid DNS server that has correct information about the hosts on the network. In the absence of such servers, static HOST-to-IP entries can be entered in either a %windir%\system32\drivers\etc\hosts or %windir%\system32\drivers\etc\lmhosts file.

  Without any of these four options, a Windows system resorts to broadcasting, which is extremely slow, to detect peer nodes. Also, if the Windows system cannot communicate with a defined WINS server or DNS server, or if incorrect information is stored on those servers, the hostname resolution will be extremely slow. Use the ping command to test whether a host can be efficiently located. The ping command should immediately respond if host name resolution is set up properly.

• When changing the state of a replication receiver (that is, to start or stop) when replication has been configured to use a secondary IP address, a misconfiguration of the /etc/hosts file may cause ttRepAdmin to print the error: Alter replication with 'ALTER REPLICATION...port 0' failed: TT0907: Unique constraint (REPSTORESIX) violated. This error is caused by replication not recognizing the local database. This situation can be confirmed by the following query:

  SELECT * FROM ttrep.ttstores WHERE is_local_store <> 0x0;
  

  If this query returns no rows, or returns a row with the main host name of the database set to the result of the hostname command rather than the host you specified, you have encountered a configuration problem with /etc/hosts.

  To correct the problem, you must make sure that the special host name you are using is defined in /etc/hosts and that there is an IP address in common between your special host name and the result of the hostname command.

  Example: your hostname command returns softswitch and your system has two Ethernet cards with the addresses 10.10.15.136 and 192.168.15.136. Then the IP addresses defined for softswitch should include both IP addresses.

6.13 SQL*Plus

• TimesTen does not support SQL*Plus connections to TimesTen databases. Use ttIsql.

6.14 SQL, utilities and procedures

• Timesten does not update the following statistics because of scalability issues caused by updating them frequently: db.table.rows_read, db.table.rows_inserted, db.table.rows_updated, db.table.rows_deleted, db.index.hash.inserts, db.index.hash.deletes, db.index.hash.rows_fetched.count, db.index.range.inserts.count, db.index.range.deletes, db.index.range.updates, db.index.range.rows_fetched.count, db.index.temporary.rows_fetched.count.

• Executing a query against multiple outer joins with the set operators UNION, MINUS or INTERSECT can result in abnormal termination. To work around this problem, define a view to encapsulate each of the outer joins. Then execute the query against the views.

• When using scalar functions that accept TIME, DATE or TIMESTAMP data types as arguments, you must prefix the function with a literal indicating the data type. For example:

  SELECT GREATEST (TIME '10:10:10', TIME '12:12:12' ) FROM DUAL; 
  

  If you do not specify the datetime literal, TimesTen treats the data type as CHAR. Functions that accept datetime literals as arguments are: GREATEST, LEAST, ROUND and ADD_MONTHS.

• The ORDER BY clause is not supported in a CREATE TABLE AS SELECT statement.

• The maximum sum of the total number of tables specified in a query and all temporary aggregates needed to handle the query is 32. A temporary aggregate is needed to handle scalar or aggregate subqueries. A query fails with the message Statement that needs more than 31 nesting levels has not been implemented when the sum of tables and temporary aggregates in a query is greater than 32.

• COUNT distinct with CHAR type uses binary sorting order and binary comparison semantics even when the NLSSORT attribute was set to a value different than binary.

• When the NLS_SORT session parameter is set to a multilingual sort (for example, FRENCH_M), the LIKE operator may produce incorrect results when the pattern match wild-card symbols are applied to the space character.

• SQL query strings in JDBC applications should contain only characters from the database character set. Unicode characters not in the database character set are converted to replacement characters during parsing of the query. Potential workarounds include:

  • Using AL32UTF8 as the database character set.

  • Parameterizing the query to avoid non-database character set characters in the query text.

• The TO_CHAR SQL function provides inconsistent results (truncates or rounds) when applied to BINARY_FLOAT and BINARY_DOUBLE values. TO_CHAR also truncates some NUMBER values that should instead be rounded.

• If an application process on HP-UX is connected to a TimesTen database and if the application process calls the ttXactIdRollback utility API for a transaction associated with the same database, the call may fail due to the inability to attach to the shared memory segment for the database.

• The fourth argument (stats) to the ttOptSetColIntvlStats built-in procedure is a compound structure that cannot be parameterized using ODBC functions. This means that a statement such as the following fails:

  SQLPrepare(hstmt, "call ttOptSetColIntvlStats('t1', 'c1', 1, ?)", SQL_NTS);
  

  Similarly, the ttIsql describe command fails because the "stats" argument does not have one of the known types.

6.15 TTClasses

• A problem with TTClasses causes NCHAR or NVARCHAR2 parameters and columns to be bound incorrectly. This results in parameter and column data being transferred to or from the database without a null terminator.

• When recompiling TTClasses on AIX 5.3, ensure that the C++ compiler is at least version 8, patch release 13 (8-feb2007). Older versions may cause programs to fail to connect to TimesTen.

6.16 Client/Server

• In the Windows ODBC Client DSN Setup dialog box, when the Server Name refers to a UNIX host, the Refresh button to get the list of DSNs on that server sometimes fails to obtain the list. Enter a known DSN in the Server DSN field to create the client DSN entry successfully. TimesTen connections from Windows using that client DSN work normally.

• When setting multiple client connections to a TimesTen server, do not set the stack size (using the -ServerStackSize daemon option or ServerStackSize attribute) to less than 64KB on 64-bit systems and 48KB on 32-bit systems. If the stack size is too small, the TimesTen Server dies with SIGSEGV on most UNIX system, or SIGBUS on HP-UX. The default stack size is 128 KB on 32-bit systems and 256 KB on 64-bit systems.

• On UNIX, when using ttlocalhost, a client of one TimesTen instance cannot connect with a server of another TimesTen instance. For example, a 32-bit TimesTen client cannot connect to a 64-bit TimesTen server when using ttlocalhost. The workaround is to use ttShmHost (shared memory IPC) or localhost (127.0.0.1).

• While using shared memory as IPC, the application may see the error message 24 from the client driver if the application reaches the system-defined, per process file descriptor limit. This may happen during a connect operation to the Client DSN when the shmat system call fails because the application has more open file descriptors than the system-defined per-process file descriptor limit.