metaload
Purpose
The metaload program is a command line alternative for loading, unloading, or resynchronizing databases. The metaload program loads the Teradata metadata into the MDS repository Database Information Metamodel (DIM). The metaload program is Unicode-enabled. It will attempt to make a UTF-16 session character set connection to Teradata databases.
If the program can establish a UTF-16 connection, the program does not require that the MDS views be installed into the DBC database with the metaviews program.
If the program cannot establish a UTF-16 connection, it will run in a mode that requires that the MDS views be installed into the DBC database with the metaviews program.
Beginning with MDS 13.0, metaload offers the ability to limit the database objects that will have metadata extracted and loaded into the repository. Limiting the metadata can improve load time and decrease the amount of disk space required by the repository but it can also result in incomplete information. Setting LoadTypes is not available in the current version of MDS Repository Explorer, but is possible using tools described in “Set MetaLoad LoadTypes” in Chapter 3 of Teradata Metadata Services Administrator Guide (3118-071A), the documentation for the previous release of MDS.
Note: If the Teradata Database is Kanji-enabled, all Kanji character sets that will be used must be installed.
Syntax
metaload -s systemname [-n dsn] [-l user] [-p password]
{-m metasu's password | -S superuser -P superuser password}
[-d database | -f file | -x file | -r | -u database | -U file]
[-L label] [-t loadtypesname] [-c profile] [-o]
[-q [on | off | list <listfile>] | -evalrels] [-h] [-norls
|
Parameter |
Description |
Required/Optional |
Circumstances |
|
-s systemname |
User-defined system name for this Teradata Database System. Multiple Teradata Databases can be loaded into the MDS repository, each distinguished by its system name. |
Required |
|
|
-n dsn
|
The ODBC System Data Source Name (DSN) for MDS to use to connect to the Teradata Database System to be loaded.
|
Required |
If the system object is not defined
|
|
Optional |
If the system object is already defined |
||
|
-l user
|
The Teradata user name for MDS to use to connect to the Teradata Database System to be loaded. If you specify the -l parameter, metaload will use the value specified in the command line parameter instead of the environment variable and system object settings.
|
Required |
|
|
Optional |
|
||
|
– |
Not needed for an unload |
||
|
-p password
|
The Teradata password for MDS to use to connect to the Teradata Database to be loaded. If you specify the -p parameter, metaload will use the value specified in the command line parameter instead of the environment variable and system object settings.
|
Required |
|
|
Optional |
Note: Using the environment variable prevents the password from being exposed to users running the ps command on Linux while metaload is running. |
||
|
– |
Not needed for an unload |
||
|
-m metasu’s password |
Password of the MDS Administrator. If the -S, -P, and -m parameters are all provided the -m parameter is ignored. If you specify the -m parameter, and the -S and -P parameters are not provided metaload will use the value specified in the command line and ignore the environment variable. |
Required |
If the -S and -P parameters are not provided or If the password is not set in the environmental variable MDSMETASUPWD Note: Using the environment variable prevents the password from being exposed to users running the ps command on Linux while metaload is running. |
|
Optional |
If the -S and -P parameters are provided or If the password is set in the environmental variable MDSMETASUPWD |
||
|
-S superuser |
Specifies the name of an MDS Administrator. The -S parameter can specify metasu. |
Required |
If the -m parameter information is not provided |
|
Optional |
|
||
|
-P superuser password |
Specifies the password of the MDS Administrator given by the -S parameter. |
Required |
If the -S parameter is provided |
|
-d database |
Limits the load (or resync) to the specified database. If the database name contains special characters, the database name must be enclosed in double quotes. |
Optional |
If this is the initial load of the system and the -d or -f options are not specified, all databases will be loaded. If this is a resync of the system and the -d or -f options are not specified, all databases which have previously been loaded will be synchronized and all other databases will be loaded. |
|
-f file |
Limits the load (or resync) to the databases listed in the specified file. The names of the databases to be loaded (or resynchronized) are read from the file. See File Formats for file format information. |
Optional |
If this is the initial load of the system and the –d or –f options are both omitted, all databases will be loaded. If this is a resync of the system and the –d or –f options are omitted, all databases that have previously been loaded will be synchronized and all other databases will be loaded. |
|
-x file |
Loads all databases except those databases specified in the file. If a database name in the file has already been loaded, it will be skipped and a warning message appears. To unload a database you must use the unload option. See File Formats for file format information. |
Optional |
|
|
-r |
Resyncs all databases that have previously been loaded. |
Optional |
|
|
-u database |
Unloads the specified database |
Optional |
|
|
-U file |
Unloads the databases listed in the specified file. See File Formats for file format information. |
Optional |
|
|
-c profile |
Specifies the security profile to assign to the DIM objects being loaded. |
Optional |
|
|
-o |
Use the override option to run metaload to complete loading of a previously aborted system load. Metaload sets a “loading” flag to prevent multiple metaload processes from attempting to load the same system simultaneously. If a running metaload process is aborted, this flag is not reset. |
Optional |
|
|
-L label |
Specifies a label name to be applied to the loaded system. The label should not be currently defined. If the label is currently defined, metaload verifies that the label is not currently attached to entries in the repository. |
Optional |
|
|
-t loadtypesname |
Provides the name of an entry in the MetaloadLoadTypes class. The entry defines the data types (tables, views, macros, and so on) that will be loaded for the system. If this parameter is used with an existing system, and resync is being done, it will replace the loadtypes entry currently associated with the system. If this parameter is not present with a new system, then all supported types will be loaded. If this parameter is not present with an existing system, that is, a resync is being done, then the system's currently associated entry will be used. Note: a system will always be associated with an entry in the MetaloadLoadTypes class |
Optional |
|
|
-evalrels |
Specifies that on a resync the relationships for all objects in the loaded system should be re-evaluated, even if the SynchronizationLevel for the object is already set to 1. This parameter cannot be used with the -q parameter |
Optional |
|
|
-h |
Displays a message describing the metaload parameters and then exits. Database names specified with the -d and -u parameters may not be given in U& format. |
– |
|
|
-q or |
This parameter requests a QuickLoad. QuickLoad only captures information from the DBC data dictionary tables. This means that all of the interrelationships between tables, views, macros, stored procedures, UDTs, and UDFs are not set. A QuickLoad loads the definitions of the tables, views, macros, and so on for each database as well as the associated columns or parameters, but that is all. For view columns, the information loaded is very limited because the data dictionary tables only provide the name and comments for a view column; information on the column data type does not appear. |
Optional |
This option is only applicable with databases that are not currently loaded; a currently loaded database that is not QuickLoaded cannot be changed to a QuickLoaded database. Use this option when your intent is to only see the contents of each database. This parameter cannot be used with the -evalrels parameter. |
|
-q off |
This parameter requests that any QuickLoaded database processed by this command should be processed normally. All relationships that are not established for a QuickLoaded database will now be evaluated. Any currently loaded database affected by this option can never revert to a QuickLoaded state. |
Optional |
This parameter cannot be used with the -evalrels parameter. |
|
-q list <listfile> |
This parameter generates a file, <listfile>, with a listing of the databases in the system that are QuickLoaded, and then exits. The file is in the format used as input for the -f option. |
Optional |
Metaload exits after generating the file. This parameter cannot be used with the -evalrels parameter. |
|
-norls |
This parameter prevents the loading or resyncing of the security constraints for a system. |
Optional |
|
File Formats
If the -f file, -x file, or -U file parameters are specified to load, resynchronize, or unload databases as listed in a file, the required format of this file is:
<DB>
databasename
</DB>
<DB>
databasename
</DB>
The heading tag <DB> and the trailing tag </DB> must each be on a separate line. There is no limit to the number of database names that can be included in the file. The special format is used to enable specification of the special characters (such as a newline) that Teradata allows to be used in a database name. If the database name contains leading spaces these must be included. Trailing spaces in the name are optional. Database names are not case sensitive but special characters must match exactly.
You can also give the database name by using the U& format. For example, U&"#0044#0042#0043" uescape '#'. This lets you include non-printing characters in the name.
Warning Messages
It is possible for Teradata to contain views that reference columns in tables that no longer exist. If metaload detects this situation, it will log warnings into the MDS error log indicating which views reference invalid columns.
It is not a requirement that all databases in a Teradata Database System be loaded into the MDS repository. Because of this, you can get the following warning messages:
Could not create the DBOwnsDB Collection for DB[metaadm] because the OwnerDB[dbc] is not loaded in MDS
Could not create the ViewHasTableColumn Collection for View [myview1] because systemname:dbname.tablename is not loaded in MDS
If you run metaload again to resynchronize the database after the owner database or the database with the view table columns has been loaded, MDS will set up these relationships.
Functionality of QuickLoad
QuickLoad is a feature of metaload intended to provide baseline information about a database’s contents as quickly as possible. The baseline information is obtained from a system’s DBC data dictionary tables. What is missing is what the data dictionary currently does not provide: the interrelationships between tables, views, macros, stored procedures, and so on. Generating the interrelationships, although sometimes necessary, is the most time-consuming work done by metaload. Measurements have shown that for databases with significant numbers of views, macros, and stored procedures, 80-90% percent of metaload’s time can be used to generate the interrelationships. QuickLoad provides a way to prevent that, when only baseline information is needed.
The information currently provided by metaload for a QuickLoaded database includes:
QuickLoad and DIM Update
The DIM Update processes are aware of QuickLoaded objects. When a DDL being processed by DIM Update references an existing object that has a SynchronizationLevel property set to -2, the current object being processed is considered out-of-sync and its SynchronizationLevel property set to zero. The database containing the object is put out-of-sync and its SynchronizationLevel property set to -1.
The nightly resync has two steps. The first step is to individually resync the databases that are known to require resyncing. It does not process all databases that are out-of-sync. The resync only processes databases that the DIM Update knows are out-of-sync with Teradata because Teradata could not send one or more DDLs for the database to be processed by DIM Update. The databases being processed can have any possible SynchronizationLevel property. Those objects with a SynchronizationLevel property of -2 receive normal processing, the full complement of relationships is established, and the database is no longer considered QuickLoaded. None of the databases processed by this step remain QuickLoaded; any later processing by metaload invokes normal processing and the setting of all known relationships.
The second step is to resync all databases that still have a SynchronizationLevel property of -1 after the first step has finished. Unlike the previous step, this step does not process QuickLoaded databases. A QuickLoaded database remains in that state until DIM Update cannot successfully process a new DDL sent by Teradata or the database is marked by Teradata as having unsent DDLs. This defers the possibly lengthy processing of a once QuickLoaded database until circumstances require it.