ttMigrate

You can perform these operations:

Saves an object from a TimesTen database into the ttMigrate data file.
Restores an object from the ttMigrate data file into a TimesTen database.
Prints details about the contents of a ttMigrate data file.

Saved objects include:

Tables
Cache group definitions
Views and materialized views
Sequences
Replication schemes
Users and user information, including database privileges for each user.

You can use the ttMigrate utility to migrate databases in three ways:

From one major release of TimesTen Classic (such as Release 18.1) to another major release of TimesTen (for example, Release 22.1).
From TimesTen Classic to TimesTen Scaleout.
From TimesTen Scaleout to TimesTen Classic.

Since database checkpoint and transaction log files are not compatible between major releases, you need to use the ttMigrate utility to upgrade major release versions of TimesTen Classic.

Note:

Users and user privileges did not exist in TimesTen 7.0 and previous releases. Hence, these objects will not be available for restoration.

For more information about TimesTen databases migration, see Moving to a Different Major Release of TimesTen Classic in Oracle TimesTen In-Memory Database Installation, Migration, and Upgrade Guide.

The data files produced by this utility are platform-dependent. For example, a ttMigrate data file created on Linux can only be restored on Linux and not any other platform, for example AIX.

By default, the ttMigrate utility restores the database using one thread. During restoration, you can specify the -numThreads option to restore the data files using multiple threads, thus potentially improving performance.

The ttMigrate utility is supported for TimesTen server DSNs. For TimesTen client DSNs use the utility ttMigrateCS (client/server version).

Note:

Although cross-release compatibility over client/server protocol is supported in TimesTen, the tool ttMigrateCS is not backward and forward release compatible; hence it can be used only for the same version client/server connections.

Required Privilege

This utility requires various privileges depending on the options specified. The instance administrator, or ADMIN, has access to all the options.

Only the instance administrator can use the -r option. If the database has been created at the time this option is used, it requires CREATE ANY TABLE, CREATE ANY SEQUENCE, CREATE ANY VIEW, CREATE ANY MATERIALIZED VIEW, CREATE ANY CACHE GROUP, CREATE ANY INDEX privileges, and ADMIN if autocreation of users is necessary. If the database is involved in replication or cache operations, then CACHE_MANAGER is also required.

Only the instance administrator can use the -c option to capture an entire database. Using the -c option to capture a subset of the database objects (tables, views, materialized views, cache groups, sequences) requires SELECT ANY TABLE and SELECT ANY SEQUENCE privileges.

Usage in TimesTen Scaleout and TimesTen Classic

This utility is predominantly supported in TimesTen Classic. Migrating a database from TimesTen Classic is the only usage of the ttMigrate utility supported in TimesTen Scaleout.

Syntax

ttMigrate {-h | -help | -?}
              {-V | -version}

To create or append a data file, use:

ttMigrate {-a | -c} [-v verbosity] [-nf] [-nr] [-fixNaN] [-saveAsCharset charset] 
[-relaxedUpgrade | -exactUpgrade]
[-activeDML | -noActiveDML] 
{DSN | -connStr connection_string} data file [[objectOwner.]objectName...]

To restore a database from a data file created by this utility, use:

ttMigrate -r  [-C ckptFreq] [-v level] [-nf] [-nr] [-fixNaN] [-numThreads n] 
[-updateStats | -estimateStats percent] [-relaxedUpgrade | -exactUpgrade] 
[-inline rule] [-noCharsetConversion] [-cacheUid uid [-cachePwd pwd]]
 [-autorefreshPaused] [-restorePublicPrivs] [-localhost host] 
[-resizeHashIndexes] 
{DSN | -connstr connection_string} dataFile [objectOwner.objectName...]

To list or display the contents of a data file created by this utility, use:

ttMigrate {-l | -L | -d | -D} dataFile [[objectOwner.]objectName...]

Options

The append (-a) or create (-c) modes, the list (-l/-L) or describe (-d/-D) modes and the restore (-r) modes are exclusive of each other. You cannot specify any of these options on the same line as any other of these options.

ttMigrate has the options:.

Option	Description
`-h` `-help` `-?`	Prints a usage message and exits.
`-V \| -version`	Prints the release number of `ttMigrate` and exits.
`-a`	Selects append mode: Appends data to a pre-existing data file, that was originally created using `ttMigrate -c`. See Create Mode (-c) and Append Mode (-a) for more details.
`-c`	Create mode: Creates an original data file. See Create Mode (-c) and Append Mode (-a) for more details.
`-v` `verbosity`	Specifies the verbosity level for messages printed when `ttMigrate` saves or restores a database. One of: `0` - Shows errors and warnings only. `1` - Prints the name of each table as it is saved or restored. `2` - Prints the name of each table or index as it is saved or restored. `3` (default) - Prints the name of each table or index as it is saved or restored and prints a dot (.) for each 10,000 rows saved or restored. `ttMigrate` ignores the `-v` option in list, long-list, describe and long-describe modes.
`-nf`	Specifies that `ttMigrate` should not save or restore foreign key information when saving or restoring ordinary (non-cached) tables.
`-nr`	Specifies that `ttMigrate` should not save or restore table rows when saving or restoring ordinary (non-cached) tables.
`-fixNaN`	Converts all `NaN`, `Inf` and `-Inf` values found in objects to 0.0. This is useful for migrating data into releases of TimesTen that do not support the `NaN`, `Inf` and `-Inf` values.
`-saveAsCharset` `charset`	Saves an object in the specified connection character set. `ttMigrate` returns an informational message if the connection character set is different from the database character set. If this option is not set, by default, `ttMigrate` saves the migrated object in the database character set.
`-relaxedUpgrade`	Save or restore the tables in a way that is compatible with a replication scheme that uses `TABLE DEFINITION CHECKING RELAXED`. `ttMigrate` ignores this option when the `-a` option is given. This option should not be used in combination with a replication scheme that uses `TABLE DEFINITION CHECKING EXACT`, or else replication may no longer work. The default is `-exactUpgrade`.
`-exactUpgrade`	Save or restore the tables in a way that is compatible with a replication scheme that uses `TABLE DEFINITION CHECKING EXACT`. `ttMigrate` ignores this option when the `-c or -a` options are given. This option should not be used in combination with a replication scheme that uses `TABLE DEFINITION CHECKING RELAXED`, or else replication may no longer work. `INLINE` variable-length columns cannot successfully be replicated to `NOT INLINE` columns. This is the default.
`-activeDML \|-noActiveDML`	Saves all tables in a foreign key hierarchy in a single transaction, maintaining consistency between these tables when there is active DML during the `ttMigrate -c` operation. If `-noActiveDML` is specified, `ttMigrate` saves each table in its own transaction, regardless of whether it is the parent or the child of a foreign key. Use this option if there is no active DML during the `ttMigrate -c` operation. `-noActiveDML` is the default.
`DSN`	Specifies an ODBC data source name of the database to be migrated.
`-connStr` `connection_string`	An ODBC connection string that specifies a database location, driver, and optionally other connection attribute settings.
`owner`	The owner of an object.
`name`	The name of the database object(s) to be saved or restored.
`-r`	Selects restore mode. Restores a database from a data file created by this utility. See Restore Mode (-r)for more details.
`-numThreads` `n`	Specifies the number of threads to use while restoring a database files. If unspecified, `ttMigrate` uses one thread to restore objects from the data file. Valid values are 1 through 32.
`-updateStats`	Specifies that `ttMigrate` should update statistics on restored tables and materialized views. `ttMigrate` ignores this option when the `-c or -a` options are given. If you specify both `-estimateStats` and `-updateStats`, statistics on restored tables are updated, not estimated. Use of this flag may improve the performance of materialized view restoration and may also improve the performance of queries on the restored tables and views.
`-estimateStats` `percent`	Specifies that `ttMigrate` should estimate statistics on restored tables and materialized views for the specified percentage of rows. Supported values for `percentRows` are 0 to 100, inclusive. `ttMigrate` ignores this option when the `-c or -a` options are given. If you specify both `-estimateStats` and `-updateStats`, statistics on restored tables are updated, not estimated. Use of this flag may improve the performance of materialized view restoration and may also improve the performance of queries on the restored tables and views.
`-inline` `rule`	Indicates the rule to be used for converting variable-length columns to `INLINE` in restore mode. The value for rule is one of: `preserve` - `ttMigrate` preserves the original `INLINE` attribute of each column. This is the default, and it is required if `-exactUpgrade` is used. `dsDefault` - `ttMigrate` uses the database's default rule for setting the `INLINE` attribute of restored columns. `maxlen` - `ttMigrate` restores as `INLINE` all variable-length columns with length <= `maxlen` and restores as `NOT INLINE` all variable-length columns with length greater than `maxlen`. If `maxlen` is 0 then all columns are restored as `NOT INLINE`. `INLINE` variable-length columns cannot successfully be replicated to `NOT INLINE` columns.
`-cacheUid`	The cache administration user ID to use when restoring asynchronous writethrough cache groups and cache groups with the `AUTOREFRESH` attribute.
`-cachePwd`	The cache administration password to use when restoring autorefresh and asynchronous writethrough cache groups and cache groups with the `AUTOREFRESH` attribute. If the cache administration user ID is provided on the command line but the cache administration password is not, then `ttMigrate` prompts for the password.
`-l`	Selects list mode. Lists the names of database objects in the specified data file. See List Mode (-l) and Long-list Mode (-L) for more details.
`-L`	Selects long-list mode. Lists the names of database objects in the specified data file and other details about the database objects. See List Mode (-l) and Long-List Mode (-L) for more details.
`-d`	Selects describe mode. Displays a short description of the objects in the data file. See Describe Mode (-d) for more details.
`-D`	Selects long-describe mode. Displays a full description of the objects in the data file. See Long-Describe Mode (-D) for more details.
`dataFile`	The path name of the data file to which objects are to be saved or from which objects are to be restored.

The following ttMigrate options are available in restore mode (-r) only:

Option	Description
`-autorefreshPaused`	Restores cache groups with `AUTOREFRESH` attribute with autorefresh state paused. Otherwise the state is set to `OFF`.
`-C` `ckptFreq`	Specifies that `ttMigrate` should checkpoint the database after restoring every `ckptFreq` megabytes of data. A value of zero (the default) specifies that `ttMigrate` should never checkpoint the database. NOTE: This option is not supported in TimesTen Scaleout.
`-convertCGTypes`	Determines the best type mapping from the underlying Oracle database tables to TimesTen cached tables using: The types of the columns in the Oracle database tables. The types of the columns stored in the migration file. The TimesTen-to-Oracle type mapping rules.
`-gridRestoreFinale`	Restores indexes and foreign keys. Use this option only for TimesTen Classic to TimesTen Scaleout migration. See Migrating a Database from TimesTen Classic to TimesTen Scaleout in Oracle TimesTen In-Memory Database Scaleout User's Guide.
`-gridRestoreRows`	Restores rows into tables. Use this option only for TimesTen Classic to TimesTen Scaleout migration. See Migrating a Database from TimesTen Classic to TimesTen Scaleout in Oracle TimesTen In-Memory Database Scaleout User's Guide.
`-localhost` `hostName`	Explicitly identifies the name or IP address of the local host when restoring replicated tables.
`-noCharsetConversion`	Restores data, retaining the connection character set that is stored in the data file. `ttMigrate` does not convert the connection character set to match the database character set. If not set, `ttMigrate` restores the data and converts the connection character set to be the same as the database character set. See also: `-saveAsCharset`. This option may be useful for legacy TimesTen users who may have migrated pre-18.1 data into a 18.1 or later release of TimesTen as `WE8ISO8895P1`, when the data is actually in another character set. If, at a later time you want to have that data interpreted according to its actual character set, use this option to migrate the data into a database that uses the data's actual character set with no character set conversion.
`-resizeHashIndexes`	Resizes user hash indexes during restore to be optimal size based on number of table rows.
`-restorePublicPrivs`	Restores privileges that were granted to `PUBLIC` after the database was created. By default, the `ttMigrate` utility does not restore privileges granted to `PUBLIC`. You must explicitly specify this option to restore privileges to `PUBLIC`.

Modes

Create Mode (-c) and Append Mode (-a)

In create mode, the ttMigrate utility saves objects from a TimesTen database into a new binary data file. If the data file does not exist, the ttMigrate utility creates it. Otherwise, ttMigrate overwrites the existing file, destroying its contents.

The data file format used by the ttMigrate utility is independent of any release of TimesTen, so it is possible to use ttMigrate to migrate data from one TimesTen release to another.

In append mode, the ttMigrate utility appends objects from a TimesTen database to an existing data file. If the data file does not exist, the ttMigrate utility creates it.

For each ordinary (non-cached) table, the ttMigrate utility saves the following:

The table description: the name and type of each of the table's columns, including primary key and nullability information.
The table's index definitions: the name of each index and the columns contained in the index. The actual contents of the index are not saved; ttMigrate only saves the information needed to rebuild the index when the table is restored.
The table's foreign key definitions. You can disable the saving of foreign key definitions using the -nf option.
The rows of the table. You can disable the saving of rows using the -nr option.

For each cache group, the ttMigrate utility saves the following:

The cache group definition: the cache group owner and name, the names of all tables in the cache group and any relevant cache group settings, such as the cache group duration. No row data is exported.
All the cached tables in the cache group: the table name, column information, table attributes (propagate or read-only), WHERE clause, if any, foreign key definitions, and index definitions.

Note:

When you migrate from TimesTen Classic to TimesTen Scaleout, if a cache group type that is not supported in TimesTen Scaleout is encountered, the utility issues an error, the cache group is skipped, and the import process continues. Additionally, static auto refresh cache groups will be created with hash distribution for all tables during the import process.

After the ttMigrate utility is used to restore a database, all autorefresh cache groups in the restored database have AUTOREFRESH state set to OFF, no matter how it was set on the source database. After restoring a cache group with ttMigrate -r, reset its AUTOREFRESH STATE to ON by using the ALTER CACHE GROUP statement (this can be done programmatically or with the ttIsql utility).

For each view, the ttMigrate utility saves the following:

All the same information as a typical table.
The query defining the view.

For each sequence, the ttMigrate utility saves the following:

The complete definition of the sequence.
The sequence's current value.

For each user (except the instance administrator), the ttMigrate utility saves the following:

User name.
The user's encrypted password.
Privileges that have been granted to the user.

For PUBLIC, the ttMigrate utility saves all privileges that have been granted to PUBLIC after database creation.

If there are any replication schemes defined, the ttMigrate utility saves all of the TTREP tables containing the replication schemes. Replication schemes should have names that are unique from all other database objects. It is not possible to migrate a replication scheme with the same name as any other database object.

Note:

The ttMigrate utility does not save the rows of a cached table into the data file, even if you have not specified the -nr option. The foreign key definitions of cached tables are always saved, regardless of the use of the -nf option, as they are needed to maintain the integrity of the cache group.

By default, the ttMigrate utility saves all database objects and users in the database to the data file, including tables, views, cache groups, sequences, users and replication schemes. Alternatively, you can give a list of database objects to be saved on the command line, except for replication schemes. The names in this list can contain the wildcard characters % (which matches one or more characters) and _ (which matches a single character). The ttMigrate utility saves all database objects that match any of the given patterns. You do not need to be fully qualify names: If a name is given with no owner, ttMigrate saves all database objects that match the specified name or pattern, regardless of their owners.

You cannot save cached tables independently of their cache groups. If you list a cached table on the command line without also listing the corresponding cache group the ttMigrate utility issues an error.

Use the -v option to control the information that ttMigrate prints while the save is in progress.

Restore Mode (-r)

In restore mode, the ttMigrate utility restores all database objects from a data file into a TimesTen database.

For each ordinary (non-cached) table, the ttMigrate utility restores:

The table, using the original owner, table name, column names, types and nullability and the original primary key.
The table's foreign keys. You can use the -nf flag to disable the restoration of foreign keys.
All indexes on the table.
All rows of the table. You can use the -nr flag to disable the restoration of rows.

For each cache group, the ttMigrate utility restores:

The cache group definition, using the original cache group owner and name. No data is imported.
Each cached table in the cache group, using the original table names, column names, types and nullability, the original primary key, the table attributes (PROPAGATE or READONLY), and the WHERE clause, if any.
The foreign key definitions of the cached tables.
All the indexes on the cached tables.

Notes

The ttMigrate utility does not restore the rows of cached tables, even if you have not specified the -nr option. The foreign key definitions of the cached tables are always restored, regardless of the use of the -nf option, as they are needed to maintain the integrity of the cache group.
All autorefresh cache groups in the restored database have the AUTOREFRESH state set to OFF, no matter how it was set on the source database. If preferred, you can set the AUTOREFRESH state of restored autorefresh cache groups to PAUSED instead of OFF using the -autorefreshPaused option.

The -exactUpgrade option is the default for both -c and -r options.

By default, the ttMigrate utility restores all tables and cache groups in the data file. Alternatively, you can list specific tables and cache groups to be restored on the command line. The names in this list must be fully qualified and cannot use wildcard characters.

You cannot restore cached tables independently of their cache groups. If you list a cached table on the command line without also listing the corresponding cache group, then the ttMigrate utility issues an error.

Use the -v option to control the information that the ttMigrate utility prints while the restoration is in progress.

The -inline option may be used to control whether variable length columns are restored as INLINE or NOT INLINE. See Type Specifications in Oracle TimesTen In-Memory Database SQL Reference. In the default mode, -inlinepreserve, ttMigrate restores all variable-length columns with the same INLINE or NOT INLINE setting with which they were saved. In the other two modes, -inlinedsDefault and -inlinemaxlen, ttMigrate restores variable-length columns equal to or shorter than a threshold length as INLINE, and restores all other variable length columns as NOT INLINE. For-inlinedsDefault, this threshold is the default automatic INLINE length for a TimesTen database. The -inlinemaxlen mode restores variable length columns with a user-specified threshold length of maxlen as INLINE, and all other variable length columns as NOT INLINE, even if they were saved as INLINE. If maxlen is 0, then all variable-length columns are restored as NOT INLINE.

List Mode (-l) and Long-List Mode (-L)

In list mode, the ttMigrate utility lists the names of database objects in the specified data file, including cached tables and the replication scheme TTREP tables.

In long-list mode, the ttMigrate utility lists the names of database objects in the data file, including cached tables and the replication scheme TTREP tables, along with the number of rows in each table and the index definitions for each table, the query defining each view and the specifications for each sequence.

By default, the ttMigrate utility lists the replication scheme name and all the database objects in the file. Alternatively, you can provide a list of names of database objects on the command line. The names in this list must be fully qualified and cannot use wildcard characters.

Describe Mode (-d)

In describe mode, the ttMigrate utility gives a short description for database objects in the specified file.

For each table, the ttMigrate utility lists the table name, the number of rows in the table, and the table's column definitions, primary key and foreign keys. For cached tables, ttMigrate also lists the table attributes (PROPAGATE or READONLY) and the table's WHERE clause, if any.

For views, the ttMigrate utility also lists the query defining the view.

For cache groups, the ttMigrate utility lists the cache group name, the number of tables in the cache group, the cache group duration and describes each cached table in the cache group.

For replication schemes, the ttMigrate utility lists the replication scheme name and all the TTREP replication scheme tables in the same manner as user tables.

By default, the ttMigrate utility describes all the database objects in the file. Alternatively, you can provide a list of names of database objects on the command line. The names in this list must be fully qualified and cannot use wildcard characters.

Long-Describe Mode (-D)

In long-describe mode, ttMigrate gives a full description for database objects in the specified file.

For each table, the ttMigrate utility lists the table's name and the number of rows in the table, the table's column definitions, primary key, foreign keys and index definitions. For cached tables, ttMigrate also lists the table attributes (PROPAGATE or READONLY) and the table's WHERE clause, if any.

For cache groups, the ttMigrate utility lists the cache group name, the number of tables in the cache group, the cache group duration and describes each cached table in the cache group.

For sequences, the ttMigrate utility lists all the values used to define the sequence and its current value.

For replication schemes, the ttMigrate utility lists all the TTREP replication scheme tables in the same manner as user tables.

By default, the ttMigrate utility describes all of database objects in the file. Alternatively, you can provide a list of names of database objects on the command line. The names in this list must be fully qualified and cannot use wildcard characters.

Cache Group Data Type Conversions

When restoring a database that contains cache groups from a TimesTen release that is earlier than 7.0, use the -convertCGTypes option to convert the data type of columns from pre-7.0 types to more clearly map with the data types of the columns in the Oracle database with which the cache group is associated.

The following table describes the type mapping.

Pre-7.0 TimesTen Type	Oracle Type	Converted Type
`TINYINT`	`NUMBER(p,s)` when s > 0	`NUMBER(p,s)`
`TINYINT`	`NUMBER(p,s)` when s <= 0	`TT_TINYINT`
`SMALLINT`	`NUMBER(p,s)` when s > 0	`NUMBER(p,s)` `TT_SMALLINT`
`SMALLINT`	`NUMBER(p,s)` when s <= 0	`TT_SMALLINT`
`INTEGER`	`NUMBER(p,s)` when s > 0	`NUMBER(p,s)`
`INTEGER`	`NUMBER(p,s)` when s <= 0	`TT_INTEGER`
`BIGINT`	`NUMBER(p,s)` when s > 0	`NUMBER(p,s)`
`BIGINT`	`NUMBER(p,s)` when s <= 0	`TT_BIGINT`
`NUMERIC(p,s)DECIMAL(p,s)`	`NUMBER`	`NUMBER`
`NUMERIC(p,s)DECIMAL(p,s)`	`NUMBER(x,y)`	`NUMBER(x,y)`
`NUMERIC(p,s)DECIMAL(p,s)`	`FLOAT(x)`	`NUMBER(p,s)`
`REAL`	Any	`BINARY_FLOAT`
`DOUBLE`	Any	`BINARY_DOUBLE`
`FLOAT(x) x <=24`	Any	`BINARY_FLOAT`
`FLOAT(x) x >= 24`	Any	`BINARY_DOUBLE`
`CHAR(x)`	Any	`ORA_CHAR(x)`
`VARCHAR(x)`	Any	`ORAVARCHAR2(x)`
`BINARY(x)`	Any	`TT_BINARY(x)`
`VARBINARY(x)`	Any	`TT_VARBINARY(x)`
`DATE`	`DATE`	`ORA_DATE`
`TIMESTAMP`	`DATE`	`ORA_DATE`
`TIME`	`DATE`	`ORA_DATE`
Any1	`TIMESTAMP(m)`	`ORA_TIMESTAMP(m)`

Note:

Any means the type value does not affect the converted result type.

For information on data types, see Data Types in Oracle TimesTen In-Memory Database SQL Reference and Mappings Between Oracle Database and TimesTen Data Types in Oracle TimesTen In-Memory Database Cache Guide.

Return Codes

The ttMigrate utility restore (-r) and create (-c) commands return the following exit codes:

0 - All objects were successfully created or restored.

1 - Some objects successfully created or restored. Some objects could not be created or restored due to errors.

2 - Fatal error, for example, could not connect or could not open the data file.

3 - Ctrl-C or another signal received during the create or restore operation.

Examples

The following command dumps all database objects from database SalesDS into a file called sales.ttm. If sales.ttm exists, ttMigrate overwrites it.

% ttMigrate -c SalesDS sales.ttm

This command appends all database objects in the SalesDS database owned by user MARY to sales.ttm:

% ttMigrate -a SalesDS sales.ttm MARY.%

This command restores all database objects from sales.ttm into the SalesDS database:

% ttMigrate -r SalesDS sales.ttm

This command restores MARY.PENDING and MARY.COMPLETED from sales.ttm into SalesDS (objects are case-insensitive):

% ttMigrate -r SalesDS sales.ttm MARY.PENDINGMARY.COMPLETED

This command lists all objects saved in sales.ttm:

% ttMigrate -l sales.ttm

Notes

When migrating backward into a release of the Oracle TimesTen In-Memory Database that does not support features in the current release, TimesTen generally issues a warning and continues without migrating the unsupported features. In a few cases, where objects have undergone conversion, ttMigrate may fail and return an error message. This may be the case with conversions of data types, character sets and primary key representation.

Consider the following restrictions, limitations, and suggestions before using the ttMigrate utility.

Cache groups: In restore mode, the presence of foreign key dependencies between tables may require the ttMigrate utility to reorder tables to ensure that a child table is not restored before a parent table.

Character columns in cached tables must have not only the same length but also the same byte semantics as the underlying Oracle database tables. Cache group migration fails when there is a mismatch in the length or length semantics of any of its cached tables.

The connection attribute PassThrough with a nonzero value is not supported with this utility and returns an error.

Character sets: By default, the ttMigrate utility stores table data in the database character set, unless you have specified the -saveAsCharset option. At restore time, conversion to another character set can be achieved by migrating the table into a database that has a different database character set.

When migrating data from a release of TimesTen that is earlier than 7.0, TimesTen assumes that the data is in the target database's character set. If the data is not in the same database character set as the target database, the data may not be restored correctly.

When migrating columns with BYTE length semantics between two databases that both support NLS but with different database character sets, it is possible for migration to fail if the columns in the new database are not large enough to hold the values in the migrate file. This could happen, for example, if the source database uses a character set whose maximum byte-length is 4 and the destination database uses a character set whose maximum byte-length is 2.

TimesTen issues a warning whenever character set conversion takes place to alert you to the possibility of data loss due to conversion.

Foreign key dependencies: In restore mode, the presence of foreign key dependencies between tables may require the ttMigrate utility to reorder tables to ensure that a child table is not restored before any of its parents. Such dependencies can also prevent a child table from being restored if any of its parent tables were not restored. For example, when restoring a table A that has a foreign key dependency on a table B, ttMigrate first checks to verify that table B exists in the database. If table B is not found, ttMigrate delays the restoration of table A until table B is restored. If table B is not restored as part of the ttMigrate session, TimesTen prints an error message indicating that table A could not be restored due to an unresolved dependency.

Replication: Before starting to migrate an entire set of replicated databases, ensure the host name and database name are the same for both the source and destination databases.

System views: TimesTen does not save the definitions or content of system vies during migration.

Other considerations: You cannot use the ttMigrate utility to:

Migrate databases between hardware platforms.
Restore data saved with ttBackup or use ttBackup to restore data saved with ttMigrate.

Migrate from one database release to a different ttMigrate release. The release of the ttMigrate utility must match the release of the database to which you are connecting.

It is recommended that you do not run DDL SQL commands via ttIsql or programmatically while running the ttMigrate -r operation to avoid lock contention issues for your application.