Oracle® TimesTen In-Memory Database

1.1 Changes for Release 11.2.1.9.5 from Release 11.2.1.9.4

1.2 Changes for Release 11.2.1.9.4 from Release 11.2.1.9.3

• A problem has been fixed in which propagation of changes to Oracle from a global cache group could not resume after an active standby failover occurred. (BugDB 14012725)

1.3 Changes for Release 11.2.1.9.3 from Release 11.2.1.9.2

• This release contains additional diagnostics that are captured in the database .inval file when an assertion is encountered.

1.4 Changes for Release 11.2.1.9.2 from Release 11.2.1.9.1

• A problem existed in which an XLALSN was not advanced in the dbheader file after an XLA application did an acknowledge. This problem is fixed. (BugDB #12317769)

• An assertion failure could occur in an active/active replication scheme with clients sending concurrent requests to the system. This problem is fixed. (BugDB #13852031)

• For OCI, a problem was fixed where the schema name was not being used if passed as the leading part of the name to OCIDescribeAny. (BugDB #13852209)

• In previous releases, mapping of a TT_TINYINT column to a NUMBER column for an Asynchronous Writethrough cache group could result in data getting corrupted. This release fixes the problem. (BugDB #13920878)

1.5 Changes for Release 11.2.1.9.1 from Release 11.2.1.9.0

• When using cache grid, a problem existed where TimesTen would interpret a temporary failure as a permanent failure. This problem is fixed. (BugDB #13830396)

1.6 Changes for Release 11.2.1.9.0 from Release 11.2.1.8.8

1.7 Changes for Release 11.2.1.8.8 from Release 11.2.1.8.5

• The JDBC Client Server driver leaked memory if the number of parameters in a PreparedStatement or CallableStatement was not an integral multiple of four. This is fixed. (BugDB 13018571)

• In previous releases, any committed deletes on cached tables in a global AWT cache group could not be propagated if the node was not attached; an attach request could not be completed until all committed updates on cached tables are propagated. This has been fixed in this release. During re-attach, after checking with all currently attached nodes that TimesTen can re-attach the failed node, grid enters a state that enables propagation to proceed. (BugDB 13416457)

  This release includes the built-in procedure ttGridFirstMemberAttach. In the case that all attached members of the grid have died, call this built-in instead of ttGridAttach to attach the first member of the grid. The syntax of the ttGridFirstMemberAttach built-in is exactly the same as the existing ttGridAttach built-in procedure, which is documented in the Oracle TimesTen In-Memory Database Reference. Call the ttGridFirstMemberAttach only from one member. Ensure that the cache agents of all other members are stopped before calling this built-in procedure or the procedure fails. (BugDB #13465148)

• In previous releases, the PLSQL_MEMORY_SIZE was internally limited to 1 GB, which caused problems for PL/SQL applications that requested more memory. In this release, the 1 GB limit has been removed. (BugDB #13548390)

• In previous releases, the response time for reacting to terminated members of a grid was too long. In this release, TimesTen reduced the response time when there are errors associated with terminated grid members during a dynamic load, global query, or insert of a global cache group. (BugDB #13476427)

1.8 Changes for Release 11.2.1.8.5 from Release 11.2.1.8.4

• By default in this release, a dynamic load is allowed on queries that specify multiple cache groups. A dynamic load may happen on each cache group that has an equality constraint with a constant or parameter on a primary or foreign key. For a join query, a dynamic load happens only when a scan is executed by the join plan and a row is not found on the local node by the scan. (BugDB 13081079)

1.9 Changes for Release 11.2.1.8.4 from Release 11.2.1.8.3

1.10 Changes for Release 11.2.1.8.3 from Release 11.2.1.8.2

• Parallel replication performance is improved by reducing compaction operations. Users are encouraged to call the ttckptblocking built-in procedure or the ttcompact utility during maintenance operations to manage their database space and to avoid long compaction operations during subsequent operations. (BugDB 10279257)

• A problem has been fixed where the subscriber data store in a replication scheme could use more heap memory than the master side and therefore run out of memory, causing replication to fail. (BugDB 11685169)

• A problem has been fixed where TimesTen would pass internal PL/SQL blocks and SQL statements to Oracle in PassThrough mode 3. In this release, only user provided PL/SQL blocks and SQL statements are passed through to Oracle. (BugDB 11711960)

• A problem in which calls to the ttOptGetColStats built-in procedure could cause data store invalidations in the sbBlkReportBadBlock function has been fixed. (BugDB 11722743)

• The message received if a user cannot login after a ttMigrate restore operation has been enhanced to indicate that you must reset user passwords. (BugDB 11785520)

• In previous releases, when a DROP ACTIVE STANDBY operation failed, the ttCWAdmin -drop operation exited with 0, which is considered "success." Now, ttCWAdmin retries the operation and returns a failure exit code when a DROP ACTIVE STANDBY operation fails. (BugDB 11792124)

• You can now select PassThrough levels 4 and 5 in the Windows TimesTen ODBC Setup dialog. (BugDB 11791297)

• In previous releases, system calls may not have appeared in sequential order in the log. In this release, the log write patterns are sequential. (BugDB 11800993)

• Dynamic load operations for asynchronous writethrough cache groups have been made more efficient by eliminating unnecessary queries against the Oracle database when a child table whose parent table has the same foreign key is already in the TimesTen cache. (BugDB 11818527)

• A problem has been fixed where TimesTen would generate incorrect checkpoint files resulting in a database recovery failure. (BugDB 11850267)

• In previous releases, under certain configurations, bidirectional replication could result in a false failed transaction message in the conflict resolution file after duplicate updates. This problem has been fixed. (BugDB 11870111)

• In previous releases, when using PL/SQL, the TimesTen database would assert when an internal error (ORA-00600) occurred. In this release, the ORA-00600 error is caught and no assertion occurs in the TimesTen database. (BugDB 11871451)

• By default TimesTen Clusterware now replicates the XLA bookmark. (BugDB 11906642)

• In previous releases, create replication failed when a replication scheme included a parent table that had an ON DELETE CASCADE relationship with a child table and that child table was not being replicated. TimesTen now returns error message 12275 "Failed to convert replicated XLA bookmarks to non-replicated for read only subscriber." TimesTen also returns additional error messages that explain why the conversion failed. (BugDB 11937457)

• In previous releases, if an application attempted to retrieve XLA records from a standby or subscriber store using a replicated bookmark, the operation would fail. This problem has been fixed. (BugDB 12347410)

• A problem has been fixed where the row count returned for a detail table and the materialized view were different. (BugDB 12367259)

• A problem has been fixed where a query on a table with two multi-column indexes would return an incorrect result set. (BugDB 12386402)

• A problem has been fixed where values in the systemstats table would only be 0 and would not update. This would occur after a TimesTen installation upgrade for data stores that had been created in a previous release of TimesTen. (BugDB 12394892)

• A problem has been fixed where bitmap indexes could cause incorrect results for an IN or GROUP BY clause. (BugDB 12400780)

1.11 Changes for Release 11.2.1.8.2 from Release 11.2.1.8.1

• A problem has been fixed where specific complex queries that contained a COUNT aggregation in one of the SELECT clauses of a SET operator combined with a UNION statement could return inconsistent results. (BugDB 11711323)

• When an instance needs to be transferred to a new grid member and the current member still needs access to the instance, the thread that moves the instance gives up its lock and retries if there is any chance of a deadlock. The elapsed time of all retries is determined by the lock time out value. (BugDB 11712111)

• Selecting rows that are being deleted, unloaded or updated could result in the following: Assertion failed: ((((sbCurHdr_p)cur)->state) == sbCurStEmpty) [index.c:/main/47:sbIxCurNext():8330] PID 14031 (timestenorad) CONN 78 (Cache Load). This problem is fixed. (BugDB 13496920)

1.12 Changes for Release 11.2.1.8.1 from Release 11.2.1.8.0

• In previous releases of TimesTen, a maximum of 50 prepared PL/SQL statements per connection was allowed. This release allows a maximum of 5,000 PL/SQL statements per connection. Previous releases also allowed the caching of only 50 recently-used PL/SQL blocks in each session. This limit also has been increased to 5,000. (BugDB 11827656)

• A problem was fixed whereby parallel replication tracks could stall due to starvation waiting on a semaphore. (BugDB 11836584)

• A problem was fixed that could cause parallel replication to get stuck when connections switch tracks and frequently rollback transactions. (BugDB 11893103)

2.1 Client/Server configurations

A TimesTen client on any supported platform can connect to a TimesTen server on any platform where TimesTen is supported.

For configuration details see "Configuring TimesTen Client and Server" in the Oracle TimesTen In-Memory Database Operations Guide.

2.2 Oracle In-Memory Database Cache

Oracle In-Memory Database Cache (IMDB Cache) allows you to cache Oracle database data in TimesTen. The TimesTen installation includes Oracle Instant Client, and the following Oracle server releases are supported with this option:

• Oracle Database 10g Release 2 (Oracle 10.2.0.4.0 or above)

• Oracle Database 11g Release 1

• Oracle Database 11g Release 2

For details about required patches, see Section 6.10, "IMDB Cache."

Also, see "Setting up the Oracle and TimesTen systems" in Oracle In-Memory Database Cache User's Guide.

2.3 Replication configurations

TimesTen-to-TimesTen replication is supported only between identical platforms and bit-levels.

Oracle Clusterware 11.1.0.7 and 11.2.0.2 are supported with TimesTen active standby pair replication. For more details, see the Oracle TimesTen In-Memory Database TimesTen to TimesTen Replication Guide

5.1 Deprecated items in Release 11.2.1.8.0

The MonInterval Clusterware attribute

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 of the same major release 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 must uninstall TimesTen and reinstall all of the components you want to have on your system.

• 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.

• To work properly on MontaVista Linux, include the libaio and libelf library packages.

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 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'.

6.8 XLA and 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.

• XLA and JMS/XLA return incorrect information for index types for a CREATE INDEX statement. The value reflected in the flag field of ttXlaCreateIndexTup_t in XLA and the INDEX_TYPE value of CREATE_INDEX in JMS/XLA, always return "R," indicating regular indexes, regardless of the actual index type.

• To use XLA bookmarks in an active standby pair that is managed by Oracle Clusterware, create the XLA bookmark after starting the active standby pair replication scheme (ttCWAdmin -start). Use ttCWAdmin -status to ensure that the role of the standby database has become 'STANDBY'.

• 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

• 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 10.2.0.4. It also applies to Oracle Database 11g Release 1 but does not occur in Oracle Database 11g Release 2. 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.

• 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 multiple UNLOAD BY ID operations 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.

• 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 ensure 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 multiple fields, 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.

• 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 must 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.

• 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 ensure 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

• 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 works 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.