Oracle® TimesTen In-Memory Database

1.1 Changes for Release 11.2.2.4.0 from Release 11.2.2.3.5

Changes in this release include:

• New Features

• Bug Fixes

1.2 Changes for Release 11.2.2.3.5 from Release 11.2.2.3.4

• A problem is fixed where a SELECT operation could result in unnecessary dynamic loads of data from Oracle that already existed in the TimesTen cache group. This problem occurred when the workload included DML operations. (BugDB 14533454)

1.3 Changes for Release 11.2.2.3.4 from Release 11.2.2.3.3

• A problem is fixed where a SELECT operation could result in multiple dynamic loads of data from Oracle. (BugDB 14499661)

• A problem is fixed where the statistics for a local dynamic cache group were incorrectly reported in the sys.systemstats table as statistics for a global dynamic cache group. (BugDB 14504836)

1.4 Changes for Release 11.2.2.3.3 from Release 11.2.2.3.2

• Previously, dynamic loads could be done only for queries with equality conditions on all columns in primary keys or on all columns in unique indexes. Now, dynamic loads will also be done with a mixture of equality or "is null" conditions on all columns in unique indexes provided that at least one equality condition is used.For more details on dynamic loads, see "Dynamically loading a cache group" in the Oracle In-Memory Database Cache User's Guide. (BugDB 14462078)

  For example:

  CREATE DYNAMIC ASYNCHRONOUS WRITETHROUGH CACHE GROUP cg FROM t1(x1 INT PRIMARY KEY, y1 INT, z1 INT);

  CREATE UNIQUE INDEX u1 ON t1(y1, z1);

  The following queries dynamically load data because all columns of the index are qualified with either an IS NULL condition or an equality with a constant or argument, and at least one column is qualified with an equality condition.

  SELECT * FROM t1 WHERE y1 IS NULL and z1=1;

  SELECT * FROM t1 WHERE y1=1 AND z1 IS NULL;

  SELECT * FROM t1 WHERE y1=1 AND z1=1;

  The following query does not dynamically load data because no column of the unique index was qualified with an equality condition:

  SELECT * FROM t1 WHERE y1 IS NULL AND z1 IS NULL;

1.5 Changes for Release 11.2.2.3.2 from Release 11.2.2.3.1

• A problem has been fixed where an assertion failure could occur when an INSERT statement contained a UNION clause in a derived table or view. (BugDB 14369779)

• A problem is fixed where a query that contained a left outer join could fail to dynamically load a writethrough cache group. (BugDB 14373623)

1.6 Changes for Release 11.2.2.3.1 from Release 11.2.2.3.0

• In previous releases, when a DROP ACTIVE STANDBY operation failed, the ttCWAdmin -drop operation exited with 0, which is considered "success." The problem has been fixed so that ttCWAdmin retries the operation and returns a failure exit code when a DROP ACTIVE STANDBY operation fails. (BugDB 14147496)

• An inconsistency in the temporary space block free list that could cause an assertion has been fixed. (BugDB 14075421)

• In previous releases, an assertion failure could occur when performing an INSERT, DELETE or TRUNCATE operation on a table while updating column statistics on the same table. In this release, TimesTen returns an error. (BugDB 14159483 and 14198331)

• A problem has been fixed on MontaVista Linux Carrier Grade Edition 6, where a TimesTen uninstall would reference an awk script in the wrong directory. (BugDB 14173419)

• Connections that used global temporary tables or PrivateCommands=1 could take 10 seconds or more to disconnect. The efficiency of disconnect in these cases has been dramatically improved. (BugDB 14198260)

• A problem has been fixed where a core dump could occur on the TimesTen server when using an automatic client failover configuration with Oracle Clusterware. The problem could occur even when the server was idle. (BugDB 14198318)

• Previously, cache group operations, such as dynamic load, would fail when connecting to Oracle if the user or application passed an empty Oracle password or did not provide a password. When multiple TimesTen sessions concurrently attempted to connect without specifying the Oracle password, it resulted in a performance degradation for subsequent connection attempts. This is related to a new Oracle database 11.2.0.2 behavior, which is described in KM Doc ID 1309738.1. Currently, if a TimesTen user or application tries to connect passing an empty password, TimesTen does not connect and returns an error message indicating to the user that the password is either empty or not provided. (BugDB 14205374)

• A problem has been fixed where TimesTen could return the wrong results when batch optimization and OR list optimization were applied to the same table scan. (BugDB 14210736)

• In rare instances, an assertion failure could invalidate the database when logs were being flushed to disk while concurrent operations were taking place in the database. (BugDB 14217041)

• A problem has been fixed where a deadlock could occur during an ALTER REPLICATION ... ADD SUBSCRIBER operation. (BugDB 14235264)

• A long running transaction could hang when an asynchronous writethrough cache group encounters a unique constraint violation. (BugDB 14239972)

• The maximum value for the cacheAWTParallelism connection attribute is now 31. (BugDB 14241071)

• When processing batch asynchronous writethrough operations, if the first operation fails, it could result in subsequent operations not serializing properly and becoming inoperative in propagating to the Oracle database. Thus, the batch operation appears to hang. (BugDB 14241173)

• A problem has been fixed where a previous connection's Oracle password would be used if an Oracle password was not specified for the current connection. (BugDB 14257660)

1.7 Changes for Release 11.2.2.3.0 from Release 11.2.2.2.2

Changes in this release include:

• New Features

• Bug Fixes

2.1 Platforms and compilers

^Footnote 1 On MontaVista CGE Linux, TimesTen only supports IMBD core functionality and replication. The following features are not supported on this platform: IMDB Cache and cache grid, the OCI API, Pro*C, PL/SQL, Clusterware and connections from Windows clients.

TimesTen is supported in virtual machines provided by Oracle VM.

2.2 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.

2.3 Oracle In-Memory Database Cache

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

• Oracle Database 10g Release 2 (10.2.0.5.0 or above)

• Oracle Database 11g Release 1 (11.1.0.7.0 or above)

• Oracle Database 11g Release 2 (11.2.0.2.0 or above)

2.4 Replication configurations

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

Oracle Clusterware 11.2.0.2 is supported with TimesTen active standby pair replication. For more details, see Oracle TimesTen In-Memory Database Replication Guide.

5.1 Deprecated items in Release 11.2.2.1.0

Using a deprecated item results in a warning.

• The -repUpgrade option of ttMigrate has been changed to -exactUpgrade to be consistent with the replication STORE clause TABLE DEFINITION CHECKING EXACT. This is the default.

• The -noRepUpgrade option of ttMigrate has been changed to -relaxedUpgrade to be consistent with the replication STORE clause TABLE DEFINITION CHECKING RELAXED.

• The -rename option has been removed from the ttMigrate utility.

• Features for XLA non-persistent mode have been deprecated and removed from the documentation. Use utilities and APIs for persistent XLA only.

• Support has been removed for TTClasses methods that take a TTStatus object as the last argument and do not return exceptions.

6.1 New issues in this release

• Foreign key constraints are not enforced by the execution of the ttLoadFromOracle built-in procedure. When using this built-in procedure (or the ttIsql command) to load rows into a table that is the referencing table (child table) of a foreign key, it is possible that a row without any matching parent is loaded. TimesTen does not detect this foreign key violation. If the data loaded from Oracle may violate a foreign key constraint, verify the foreign key constraint manually after loading both the child and the parent table.

• A problem exists with TimesTen Oracle Clusterware exists where killing the ttCRSMaster process of the active database results in a role switch.

6.2 Cache Advisor

• The list of known problems and limitations for the Cache Advisor is in the readme.html file in install_dir/ttcacheadv in your TimesTen instance.

6.3 Client/Server

• In the Windows ODBC Client DSN Setup dialog box, when the Server Name refers to a UNIX host, pressing 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.

• 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.

6.4 IMDB Cache

• You cannot use a hash (#) symbol in a table name in a cache group.

• Dynamic load might not occur under the following condition: The query specifies more than one table of the cache group and the first table in the plan is a cache group table without a dynamic load condition. Such a plan is possible when the cache group is empty.

  This can be fixed by either:

  • Setting the join order so the table with the dynamic load condition is the left-most table of the join, or

  • Setting fake statistics so the tables without the dynamic load condition are not empty.

• Global cache group operations are not supported on Windows systems.

• If there are indexes on the Oracle database that are there to enforce constraints, you must duplicate them on TimesTen. This restriction applies for AWT cache groups when parallel propagation is enabled.

• In the following scenario:

  • There are multiple AWT cache groups.

  • There are pending DML operations to be applied to be propagated to Oracle for an AWT cache group.

  • The AWT cache group is dropped and then recreated.

  The expected behavior is that the pending DML will not be applied to the Oracle database. A problem exists where the pending DML is applied to Oracle. To work around this problem, do one of the following:

  • Drop all AWT cache groups before any cache group is recreated.

    OR

  • Call the ttRepSubscriberWait build-in procedure against the Oracle database to ensure that all pending DML are applied to Oracle before dropping the cache group.

• If a foreign key on an Oracle database corresponds to cached tables, the foreign key must have an index on it. If there is no index on the foreign key, TimesTen returns an error at the time of cache group creation. This restriction applies for AWT cache groups when parallel propagation is enabled.

• 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.

• 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 10.2.0.5.

  See My Oracle Support 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.

• 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.

6.5 Installing and uninstalling TimesTen

• The section "Installing TimesTen on UNIX systems" in the Oracle TimesTen In-Memory Database Installation Guide says "Download TimesTen to your system. The download consists of a gzipped TAR file that is named timestenrelease.platform.tar.gz, for example, timesten112230.linux86.tar.gz." The passage should instead indicate only that the TimesTen tar file name indicates the platform and release number. The file name is not in the format indicated.

• For databases on Linux systems where PermSize+TempSize+LogBufMB+20MB > 256 GB, you must have Large Pages configured to accommodate the size of the shared segment.

• On Windows 64-bit systems, you need to compile the QuickStart TTClasses demos before you can use them.

• 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 TimesTen on a new 64-bit Linux system, you may find that it is not enabled for 32-bit applications. Select the Compatibility Arch Support and Compatibility Arch Development Support packages to install architecture specific support for your system.

• On Windows 64-bit systems, you can do either a 64-bit installation (typical) or a 32-bit installation, but you cannot do both a 64-bit installation and a 32-bit installation of the same major release. (You could, however, have a 64-bit installation of the 11.2.2.3.0 release and a 32-bit installation of the 11.2.1.9.0 release, for example.)

• 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.

• 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.

• 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.

6.6 JDBC

• If a JDBC application running in a time zone that has Daylight Savings Time selects a nonexistent 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'.

• SQL statements 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 statement to avoid characters that are not in the database character set in the query text.

6.7 ODBC

• The ODBC SQLExtendedFetch function appears in TimesTen header files. However, TimesTen does not support this function.

6.8 PL/SQL

• 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 GB. 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.

• 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.

6.9 Replication

• The default handling of cache groups when duplicating databases is inconsistent between the ttRepAdmin -duplicate command line utility and the ODCB ttRepDuplicateEX utility. When using ttRepAdmin, cache groups are converted to regular tables by default (-noKeepCG). When using ttRepDuplicateEX, cache groups are retained by default.

• 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.

• 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.

6.10 SQL, utilities and procedures

• TimesTen BINARY_DOUBLE and BINARY_FLOAT are approximate data types. When storing and retrieving data of these types, the least significant digits may be rounded or truncated. You should avoid using columns of these types in primary keys, unique keys and foreign keys.

• When the same column alias name is used in a view definition and a query that accesses the view, TimesTen might incorrectly issue the TT2210: Column reference of XXX is ambiguous error. The workaround is to explicitly assign a different column alias name to the column.

• Deleting rows from a table that has out-of-line columns and dropping that table in the same transaction results in an assertion failure when using DDLCommitBehavior=1. To work around this problem, add a commit between the DELETE statement and the DROP TABLE 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 statements 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 statement to avoid characters that are not in the database character set in the query text.

6.11 SQL*Plus

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

6.12 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.

6.13 TimesTen OCI support

• TimesTen OCI documentation primarily just documents differences between TimesTen OCI support and Oracle Database OCI support. TimesTen customers rely on the Oracle Database documentation for general information and functionality.

  Please be aware of the following errata related to the OCIDescribeAny() function in the "Describing Schema Metadata" chapter of the Oracle Database 11.2.0.2 OCI programmer's guide:

  1. Under "Parameter Attributes", the documentation lists OCI_ATTR_NUM_PARAMS under attributes of all parameters. OCI_ATTR_NUM_PARAMS is actually an attribute only for list parameters.

  2. The value returned when you get the attribute OCI_ATTR_LIST_COLUMNS from OCI_PTYPE_TABLE or OCI_PTYPE_VIEW is of type OCIParam*. This is correctly documented in Appendix A but incorrectly documented as type void* under "Table or View Parameters" in the "Describing Schema Metadata" chapter.

  3. The documentation mentions attribute OCI_ATTR_LIST_TYPE for list types (OCI_ATTR_PTYPE_LIST). This is incorrect. The attribute is OCI_ATTR_LTYPE.

  4. Under "Schema Attributes", the OCI_ATTR_LISTS_OBJECTS attribute is said to be of type OraText*. The type is actually OCIParam*.

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

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

• On Windows platforms, the 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 compiling a Pro*C/C++ demo, this message may appear: "System default option values taken from: install_dir/ttoracle_home/instantclient_11_2/precomp/admin/pcscfg.cfg." The path name may be incorrect.

6.15 TTClasses

• The TTCmd::setParamNull() method cannot be used to set NULL LOB data in an Oracle Database table using passthrough. Instead, use literals in INSERT or UPDATE statements.

6.16 Upgrading TimesTen

• The ttMigrate utility cannot migrate foreign key dependencies between objects owned by different users to TimesTen release 11.2.1 and later from release 7.0 and older 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 and later from release 7.0 and older 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.

6.17 XLA and JMS/XLA

See Oracle TimesTen In-Memory Database C Developer's Guide for details about XLA (Transaction Log API). See Oracle TimesTen In-Memory Database Java Developer's Guide for details about JMS/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 are always R, indicating regular indexes, regardless of the actual index type.

• In TimesTen JMS/XLA, the MapMessage.getString() method currently returns NULL for FLOAT data.

• This limitation applies to JMS/XLA, ODBC/XLA and TTClasses/XLA. When a modification of a LOB column is committed, XLA does not return the value of the LOB. XLA does indicate the following are true:

  • Whether the LOB has been inserted, updated or deleted

  • Whether the value of the LOB column is NULL or not NULL

  • Whether the length of the LOB is zero

  • Whether the value of the LOB is undefined

• TimesTen does not generate an XLA record for CREATE MATERIALIZED VIEW LOG operations.

• 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.

• 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.