HELPLIB.HLB  —  RMU72  Unload  Database
    Copies the data from a specified table or view of the database
    into one of the following:

    o  A specially structured file that contains both the data and
       the metadata (.unl).

    o  An RMS file that contains data only (.unl). This file is
       created when you specify the Record_Definition qualifier.
       (The Record_Definition qualifier also creates a second file,
       with file extension .rrd, that contains the metadata.)

    Data from the specially structured file can be reloaded by using
    the RMU Load command only. Data from the RMS file can be reloaded
    using the RMU Load command or by using an alternative utility
    such as is offered by DATATRIEVE.

1  –  Description

    The RMU Unload command copies data from a specified table or view
    and places it in a specially structured file or in an RMS file.
    Be aware that the RMU Unload command does not remove data from
    the specified table; it merely makes a copy of the data.

    The RMU Unload command can be used to do the following:

    o  Extract data for an application that cannot access the Oracle
       Rdb database directly.

    o  Create an archival copy of data.

    o  Perform restructuring operations.

    o  Sort data by defining a view with a sorted-by clause, then
       unloading that view.

    The specially structured files created by the RMU Unload command
    contain metadata for the table that was unloaded. The RMS files
    created by the RMU Unload command contain only data; the metadata
    can be found either in the data dictionary or in the .rrd file
    created using the Record_Definition qualifier. Specify the
    Record_Definition qualifier to exchange data with an application
    that uses RMS files.

    The LIST OF BYTE VARYING (segmented string) data type cannot be
    unloaded into an RMS file; however, it can be unloaded into the
    specially structured file type.

    Data type conversions are valid only if Oracle Rdb supports the
    conversion.

    The RMU Unload command executes a read-only transaction to gather
    the metadata and user data to be unloaded. It is compatible with
    all operations that do not require exclusive access.

2  –  Format

  (B)0RMU/Unload root-file-spec table-name output-file-name

  Command Qualifiers                                  x Defaults
                                                      x
  /Allocation=n                                       x /Allocation=2048
  /Buffers=n                                          x See description
  /Commit_Every=n                                     x None
  /[No]Compression[=options]                          x /Nocompression
  /Debug_Options={options}                            x See description
  /Delete_Rows                                        x None
  /[No]Error_Delete                                   x See description
  /Extend_Quantity=number-blocks                      x /Extend_Quantity=2048
  /Fields=(column-name-list)                          x See description
  /Flush={Buffer_End|On_Commit}                       x See description
  /[No]Limit_To=n                                     x /Nolimit_To
  /Optimize={options}                                 x None
  /Record_Definition={([No]File|Path)=name,options}   x See description
  /Reopen_Count=n                                     x None
  /Row_Count=n                                        x See description
  /Statistics_Interval=seconds                        x See description
  /Transaction_Type[=(transaction_mode,options...)]   x See description
  /[No]Virtual_Fields[=[No]Automatic,[No]Computed_By] x /Novirtual_Fields

3  –  Parameters

3.1  –  root-file-spec

    The root file specification of the database from which tables or
    views will be unloaded. The default file extension is .rdb.

3.2  –  table-name

    The name of the table or view to be unloaded, or its synonym.

3.3  –  output-file-name

    The destination file name. The default file extension is .unl.

4  –  Command Qualifiers

4.1  –  Allocation

    Allocation=n

    Enables you to preallocate the generated output file. The
    default allocation is 2048 blocks; when the file is closed it
    is truncated to the actual length used.

    If the value specified for the Allocation qualifier is less
    than 65535, it becomes the new maximum for the Extend_Quantity
    qualifier.

4.2  –  Buffers

    Buffers=n

    Specifies the number of database buffers used for the unload
    operation. If no value is specified, the default value for
    the database is used. Although this qualifier might affect
    the performance of the unload operation, the default number of
    buffers for the database usually allows adequate performance.

4.3  –  Commit Every

    Commit_Every=n

    Turns the selection query into a WITH HOLD cursor so that the
    data stream is not closed by a commit. Refer to the Oracle Rdb7
    SQL Reference Manual for more information about the WITH HOLD
    clause.

4.4  –  Compression

    Compression[=options]
    NoCompression

    Data compression is applied to the user data unloaded to the
    internal (interchange) format file. Table rows, null byte vector
    and LIST OF BYTE VARYING data are compressed using either the LZW
    (Lempel-Ziv-Welch) technique or the ZLIB algorithm developed by
    Jean-loup Gailly and Mark Adler. Table metadata (column names and
    attributes) are never compressed and the resulting file remains
    a structured interchange file. Allowing compression allows the
    result data file to be more compact, using less disk space and
    permitting faster transmission over communication lines. This
    file can also be processed using the RMU Dump Export command.

    The default value is Nocompression.

    This qualifier accepts the following optional keywords (ZLIB is
    the default if no compression algorithm is specified):

    o  LZW

       Selects the LZW compression technique.

    o  ZLIB

       Selects the ZLIB compression technique. This can be modified
       using the LEVEL option.

    o  LEVEL=number

       ZLIB allows further tuning with the LEVEL option that accepts
       a numeric level between 1 and 9. The default of 6 is usually
       a good trade off between result file size and the CPU cost of
       the compression.

    o  EXCLUDE_LIST[=(column-name,...)]

       It is possible that data in LIST OF BYTE VARYING columns is
       already in a compressed format (for instance images as JPG
       data) and therefore need not be compressed by RMU Unload.
       In fact, compression in such cases might actually cause
       the output to grow. The EXCLUDE_LIST option will disable
       compression for LIST OF BYTE VARYING columns. Specific column
       names can be listed, or if omitted, all LIST OF BYTE VARYING
       columns will be excluded from compression.

    Only the user data is compressed. Therefore, additional
    compression may be applied using various third party compression
    tools, such as ZIP. It is not the goal of RMU to replace such
    tools.

    The qualifier RECORD_DEFINITION (or RMS_RECORD_DEF) is not
    compatible /COMPRESSION. Note that the TRIM option for DELIMITED
    format output can be used to trim trailing spaces from VARCHAR
    data.

4.5  –  Debug Options

    Debug_Options={options}

    The Debug_Options qualifier allows you to turn on certain debug
    functions. The Debug_Options qualifier accepts the following
    options:

    o  [NO]TRACE

       Traces the qualifier and parameter processing performed by
       RMU Unload. In addition, the query executed to read the table
       data is annotated with the TRACE statement at each Commit
       (controlled by Commit_Every qualifier). When the logical name
       RDMS$SET_FLAGS is defined as "TRACE", then a line similar to
       the following is output after each commit is performed.

       ~Xt: 2009-04-23 15:16:16.95: Commit executed.

       The default is NOTRACE.

       $RMU/UNLOAD/REC=(FILE=WS,FORMAT=CONTROL) SQL$DATABASE WORK_STATUS WS/DEBUG=TRACE
       Debug = TRACE
       * Synonyms are not enabled
       Row_Count = 500
       Message buffer: Len: 13524
       Message buffer: Sze: 27, Cnt: 500, Use: 4 Flg: 00000000
       %RMU-I-DATRECUNL,   3 data records unloaded.

    o  [NO]FILENAME_ONLY

       When the qualifier Record_Definition=Format:CONTROL is used,
       the name of the created unload file is written to the control
       file (.CTL). When the keyword FILENAME_ONLY is specified, RMU
       Unload will prune the output file specification to show only
       the file name and type. The default is NOFILENAME_ONLY.

       $RMU/UNLOAD/REC=(FILE=TT:,FORMAT=CONTROL) SQL$DATABASE WORK_STATUS WS/DEBUG=
       FILENAME
       --
       -- SQL*Loader Control File
       --   Generated by: RMU/UNLOAD
       --   Version:      Oracle Rdb X7.2-00
       --   On:           23-APR-2009 11:12:46.29
       --
       LOAD DATA
       INFILE 'WS.UNL'
       APPEND
       INTO TABLE "WORK_STATUS"
       (
        STATUS_CODE                     POSITION(1:1) CHAR NULLIF (RDB$UL_NB1 = '1')
       ,STATUS_NAME                     POSITION(2:9) CHAR NULLIF (RDB$UL_NB2 = '1')
       ,STATUS_TYPE                     POSITION(10:23) CHAR NULLIF (RDB$UL_NB3 = '1')
       -- NULL indicators
       ,RDB$UL_NB1               FILLER POSITION(24:24) CHAR -- indicator for
       STATUS_CODE
       ,RDB$UL_NB2               FILLER POSITION(25:25) CHAR -- indicator for
       STATUS_NAME
       ,RDB$UL_NB3               FILLER POSITION(26:26) CHAR -- indicator for
       STATUS_TYPE
       )
       %RMU-I-DATRECUNL,   3 data records unloaded.

    o  [NO]HEADER

       This keyword controls the output of the header in the control
       file. To suppress the header use NOHEADER. The default is
       HEADER.

    o  APPEND, INSERT, REPLACE, TRUNCATE

       These keywords control the text that is output prior to the
       INTO TABLE clause in the control file. The default is APPEND,
       and only one of these options can be specified.

4.6  –  Delete Rows

    Specifies that Oracle Rdb delete rows after they have been
    unloaded from the database. You can use this qualifier with the
    Commit_Every qualifier to process small batches of rows.

    If constraints, triggers, or table protection prevent the
    deletion of rows, the RMU Unload operation will fail. The Delete_
    Rows qualifier cannot be used with non-updatable views, those
    containing joins, or aggregates (union or group by).

4.7  –  Error Delete

    Noerror_Delete

    Specifies whether the unload and record definition files should
    be deleted on error. By default, the RMU Unload command deletes
    the unload and record definition files if an unrecoverable error
    occurs that causes an abnormal termination of the unload command
    execution. Use the Noerror_Delete qualifier to retain the files.

    If the Delete_Rows qualifier is specified, the default for this
    qualifier is Noerror_Delete. This default is necessary to allow
    you to use the unload and record definition files to reload the
    data if an unrecoverable error has occurred after the delete of
    some of the unloaded rows has been committed. Even if the unload
    file is retained, it may not be able to reload the data using the
    RMU Load command if the error is severe enough to prevent the RMU
    error handler from continuing to access the unload file once the
    error is detected.

    If the Delete_Rows qualifier is not specified, the default is
    Error_Delete.

4.8  –  Extend Quantity

    Extend_Quantity=number-blocks

    Sets the size, in blocks, by which the unload file (.unl) can
    be extended. The minimum value for the number-blocks parameter
    is 1; the maximum value is 65535. If you provide a value for the
    Allocation qualifier that is less than 65535, that value becomes
    the maximum you can specify.

    If you do not specify the Extend_Quantity qualifier, the default
    block size by which .unl files can be extended is 2048 blocks.

4.9  –  Fields

    Fields=(column-name-list)

    Specifies the column or columns of the table or view to be
    unloaded from the database. If you list multiple columns,
    separate the column names with a comma, and enclose the list
    of column names within parentheses. This qualifier also specifies
    the order in which the columns should be unloaded if that order
    differs from what is defined for the table or view. Changing the
    structure of the table or view could be useful when restructuring
    a database or when migrating data between two databases with
    different metadata definitions. The default is all the columns
    defined for the table or view in the order defined.

4.10  –  Flush

    Flush=Buffer_End
    Flush=On_Commit

    Controls when internal RMS buffers are flushed to the unload
    file. By default, the RMU Unload command flushes any data left
    in the internal RMS file buffers only when the unload file is
    closed. The Flush qualifier changes that behavior. You must use
    one of the following options with the Flush qualifier:

    o  Buffer_End

       The Buffer_End option specifies that the internal RMS buffers
       be flushed to the unload file after each unload buffer has
       been written to the unload file.

    o  On_Commit

       The On_Commit option specifies that the internal RMS buffers
       be flushed to the unload file just before the current unload
       transaction is committed.

    If the Delete_Rows qualifier is specified, the default for this
    qualifier is Flush=On_Commit. This default is necessary to allow
    you to use the unload and record definition files to reload the
    data if an unrecoverable error has occurred after the delete of
    some of the unloaded rows has been committed.

    If the Delete_Rows qualifier is not specified, the default is to
    flush the record definition buffers only when the unload files
    are closed.

    More frequent flushing of the internal RMS buffers will avoid the
    possible loss of some unload file data if an error occurs and the
    Noerror_Delete qualifer has been specified. Additional flushing
    of the RMS internal buffers to the unload file can cause the RMU
    Unload command to take longer to complete.

4.11  –  Limit To

    Limit_To=n
    Nolimit_To

    Limits the number of rows unloaded from a table or view. The
    primary use of the Limit_To qualifier is to unload a data sample
    for loading into test databases. The default is the Nolimit_To
    qualifier.

4.12  –  Optimize

    Optimize={options}

    Controls the query optimization of the RMU Unload command. You
    must use one or more of the following options with the Optimize
    qualifier:

    o  Conformance={Optional|Mandatory}

       This option accepts two keywords, Optional or Mandatory, which
       can be used to override the settings in the specified query
       outline.

       If the matching query outline is invalid, the
       Conformance=Mandatory option causes the query compile, and
       hence the RMU Unload operation, to stop. The query outline
       will be one which either matches the string provided by
       the Using_Outline or Name_As option or matches the query
       identification.

       The default behavior is to use the setting within the query
       outline. If no query outline is found, or query outline usage
       is disabled, then this option is ignored.

    o  Fast_First

       This option asks the query optimizer to favor strategies that
       return the first rows quickly, possibly at the expense of
       longer overall retrieval time. This option does not override
       the setting if any query outline is used.

       This option cannot be specified at the same time as the Total_
       Time option.

                                      NOTE

          Oracle Corporation does not recommend this optimization
          option for the RMU Unload process. It is provided only
          for backward compatibility with prior Rdb releases when
          it was the default behavior.

    o  Name_As=query_name

       This option supplies the name of the query. It is used to
       annotate output from the Rdb debug flags (enabled using the
       logical RDMS$SET_FLAGS) and is also logged by Oracle TRACE.

       If the Using_Outline option is not used, this name is also
       used as the query outline name.

    o  Selectivity=selectivity-value

       This option allows you to influence the Oracle Rdb query
       optimizer to use different selectivity values.

       The Selectivity option accepts the following keywords:

       -  Aggressive - assumes a smaller number of rows is selected
          compared to the default Oracle Rdb selectivity

       -  Sampled - uses literals in the query to perform preliminary
          estimation on indices

       -  Default - uses default selectivity rules

       The following example shows a use of the Selectivity option:

       $RMU/UNLOAD/OPTIMIZE=(TOTAL_TIME,SELECTIVITY=SAMPLED) -
       _$  SALES_DB CUSTOMER_TOP10 TOP10.UNL

       This option is most useful when the RMU Unlaod command
       references a view definition with a complex predicate.

    o  Sequential_Access

       This option requests that index access be disabled for this
       query. This is particularly useful for RMU Unload from views
       against strictly partitioned tables. Strict partitioning is
       enabled by the PARTITIONING IS NOT UPDATABLE clause on the
       CREATE or ALTER STORAGE MAP statements. Retrieval queries
       only use this type of partition optimization during sequential
       table access.

       This option cannot be specified at the same time as the Using_
       Outline option.

    o  Total_Time

       This option requests that total time optimization be applied
       to the unload query. It does not override the setting if any
       query outline is used.

       In some cases, total time optimization may improve performance
       of the RMU Unload command when the query optimizer favors
       overall performance instead of faster retrieval of the first
       row. Since the RMU Unload process is unloading the entire set,
       there is no need to require fast delivery of the first few
       rows.

       This option may not be specified at the same time as the Fast_
       First option. The Optimize=Total_Time behavior is the default
       behavior for the RMU Unload command if the Optimize qualifier
       is not specified.

    o  Using_Outline=outline_name

       This option supplies the name of the query outline to be
       used by the RMU Unload command. If the query outline does
       not exist, the name is ignored.

       This option may not be specified at the same time as the
       Sequential_Access option.

4.13  –  Record Definition

    Record_Definition=[File=name,options]
    Record_Definition=[Path=name,options]
    Record_Definition=Nofile

    Creates an RMS file containing the record structure definition
    for the output file. The record description uses the CDO record
    and field definition format. The default file extension is .rrd.

    If you omit the File=name or Path=name option you must specify an
    option.

    The date-time syntax in .rrd files generated by this qualifier
    changed in Oracle Rdb V6.0 to make the .rrd file compatible with
    the date-time syntax support for Oracle CDD/Repository V6.1. The
    RMU Unload command accepts both the date-time syntax generated
    by the Record_Definition qualifier in previous versions of Oracle
    Rdb and the syntax generated in Oracle Rdb V6.0 and later.

    See the help entry for RRD_File_Syntax for more information on
    .rrd files and details on the date-time syntax generated by this
    qualifier.

    The options are:

    o  Format=(Text)

       If you specify the Format=(Text) option, Oracle RMU converts
       all data to printable text before unloading it.

    o  Format=Control

       The Format=Control option provides support for SQL*Loader
       control files and portable data files. The output file
       defaults to type .CTL.

       FORMAT=CONTROL implicitly uses a portable data format as TEXT
       rather than binary values. The unloaded data files are similar
       to that generated by FORMAT=TEXT but includes a NULL vector to
       represent NULL values ('1') and non-NULL values ('0').

       The SQL*Loader control file uses this NULL vector to set NULL
       for the data upon loading.

       When FORMAT=CONTROL is used, the output control file and
       associated data file are intended to be used with the Oracle
       RDBMS SQL*Loader (sqlldr) command to load the data into an
       Oracle RDBMS database table. LIST OF BYTE VARYING (SEGMENTED
       STRING) columns are not unloaded.

       The keywords NULL, PREFIX, SEPARATOR, SUFFIX, and TERMINATOR
       only apply to DELIMITED_TEXT format and may not be used in
       conjunction with the CONTROL keyword.

       DATE VMS data is unloaded including the fractional seconds
       precision. However, when mapped to Oracle DATE type in the
       control file, the fractional seconds value is ignored. It
       is possible to modify the generated control file to use the
       TIMESTAMP type and add FF to the date edit mask.

                                      NOTE

          The RMU Load command does not support loading data using
          FORMAT=Control.

    o  Format=XML

       The Format=XML option causes the output Record_Definition file
       type to default to .DTD (Document Type Definition). The output
       file defaults to type .XML. The contents of the data file is
       in XML format suitable for processing with a Web browser or
       XML application.

       If you use the Nofile option or do not specify the File or
       Path keyword, the DTD is included in the XML output file
       (internal DTD). If you specify a name with the File or Path
       keyword to identify an output file, the file is referenced as
       an external DTD from within the XML file.

       The XML file contains a single table that has the name of the
       database and multiple rows named <RMU_ROW>. Each row contains
       the values for each column in printable text. If a value is
       NULL, then the tag <NULL/> is displayed. Example 16 shows this
       behavior.

                                      NOTE

          The RMU Load command does not support loading data using
          FORMAT=XML.

    o  Format=(Delimited_Text [,delimiter-options])

       If you specify the Format=Delimited_Text option, Oracle RMU
       applies delimiters to all data before unloading it.

       Note that DATE VMS dates are output in the collatable time
       format, which is yyyymmddhhmmsscc. For example, March 20, 1993
       is output as: 1993032000000000.

       If the Format option is not used, Oracle RMU outputs data to
       a fixed-length binary flat file. If the Format=Delimited_Text
       options is not used, VARCHAR(n) strings are padded with blanks
       when the specified string has fewer characters than n so that
       the resulting string is n characters long.

       Delimiter options (and their default values if you do not
       specify delimiter options) are:

       -  Prefix=string

          Specifies a prefix string that begins any column value in
          the ASCII output file. If you omit this option, the column
          prefix will be a quotation mark (").

       -  Separator=string

          Specifies a string that separates column values of a row.
          If you omit this option, the column separator will be a
          single comma (,).

       -  Suffix=string

          Specifies a suffix string that ends any column value in
          the ASCII output file. If you omit this option, the column
          suffix will be a quotation mark (").

       -  Terminator=string

          Specifies the row terminator that completes all the column
          values corresponding to a row. If you omit this option, the
          row terminator will be the end of the line.

       -  Null=string

          Specifies a string, which when found in the database
          column, is unloaded as NULL in the output file.

          The Null option can be specified on the command line as any
          one of the following:

          *  A quoted string

          *  An empty set of double quotes ("")

          *  No string

          The string that represents the null character must be
          quoted on the Oracle RMU command line. You cannot specify a
          blank space or spaces as the null character. You cannot use
          the same character for the Null value and other Delimited_
          Text options.

                                      NOTE

          The values of each of the strings specified in the
          delimiter options must be enclosed within quotation
          marks. Oracle RMU strips these quotation marks while
          interpreting the values. If you want to specify a
          quotation mark (") as a delimiter, specify a string
          of four quotation marks. Oracle RMU interprets four
          quotation marks as your request to use one quotation
          mark as a delimiter. For example, Suffix = """".

          Oracle RMU reads these quotation marks as follows:

          o  The first quotation mark is stripped from the string.

          o  The second and third quotation mark are interpreted
             as your request for one quotation mark (") as a
             delimiter.

          o  The fourth quotation mark is stripped.

          This results in one quotation mark being used as a
          delimiter.

          Furthermore, if you want to specify a quotation mark as
          part of the delimited string, you must use two quotation
          marks for each quotation mark that you want to appear in
          the string. For example, Suffix = "**""**" causes Oracle
          RMU to use a delimiter of **"**.

    o  Trim=option

       If you specify the Trim=option keyword, leading and/or
       trailing spaces area removed from each output field. Option
       supports three keywords:

       o  TRAILING - trailing spaces will be trimmed from CHARACTER
          and CHARACTER VARYING (VARCHAR) data that is unloaded.
          This is the default setting if only the TRIM option is
          specified.

       o  LEADING - leading spaces will be trimmed from CHARACTER and
          CHARACTER VARYING (VARCHAR) data that is unloaded.

       o  BOTH - both leading and trailing spaces will be trimmed.

    When the Record_Definition qualifier is used with load or unload
    operations, and the Null option to the Delimited_Text option
    is not specified, any null values stored in the rows of the
    tables being loaded or unloaded are not preserved. Therefore,
    if you want to preserve null values stored in tables and you are
    moving data within the database or between databases, specify the
    Null option with Delimited_Text option of the Record_Definition
    qualifier.

4.14  –  Reopen Count

    Reopen_Count=n

    The Reopen_Count=n qualifier allows you to specify how many
    records are written to an output file. The output file will
    be re-created (that is, a new version of the file will be
    created) when the record count reaches the specified value.
    The Reopen_Count=n qualifier is only valid when used with the
    Record_Definition or Rms_Record_Def qualifiers.

4.15  –  Rms Record Def

    Rms_Record_Def=(File=name[,options])

    Rms_Record_Def=(Path=name[,options])

    Synonymous with the Record_Definition qualifier. See the
    description of the Record_Definition qualifier.

4.16  –  Row Count

    Row_Count=n

    Specifies that Oracle Rdb buffer multiple rows between the Oracle
    Rdb server and the RMU Unload process. The default value for n
    is 500 rows; however, this value should be adjusted based on
    working set size and length of unloaded data. Increasing the row
    count may reduce the CPU cost of the unload operation. For remote
    databases, this may significantly reduce network traffic for
    large volumes of data because the buffered data can be packaged
    into larger network packets.

    The minimum value you can specify for n is 1. The default row
    size is the value specified for the Commit_Every qualifier or
    500, whichever is smaller.

4.17  –  Statistics Interval

    Statistics_Interval=seconds

    Specifies that statistics are to be displayed at regular
    intervals so that you can evaluate the progress of the unload
    operation.

    The displayed statistics include:

    o  Elapsed time

    o  CPU time

    o  Buffered I/O

    o  Direct I/O

    o  Page faults

    o  Number of records unloaded since the last transaction was
       committed

    o  Number of records unloaded so far in the current transaction

    If the Statistics_Interval qualifier is specified, the seconds
    parameter is required. The minimum value is 1. If the unload
    operation completes successfully before the first time interval
    has passed, you receive only an informational message on the
    number of files unloaded. If the unload operation is unsuccessful
    before the first time interval has passed, you receive error
    messages and statistics on the number of records unloaded.

    At any time during the unload operation, you can press Ctrl/T to
    display the current statistics.

4.18  –  Transaction Type

    Transaction_Type[=(transaction_mode,options,...)]

    Allows you to specify the transaction mode, isolation level, and
    wait behavior for transactions.

    Use one of the following keywords to control the transaction
    mode:

    o  Automatic

       When Transaction_Type=Automatic is specified, the transaction
       type depends on the current database settings for snapshots
       (enabled, deferred, or disabled), transaction modes available
       to this user, and the standby status of the database.
       Automatic mode is the default.

    o  Read_Only

       Starts a Read_Only transaction.

    o  Exclusive

       Starts a Read_Write transaction and reserves the table for
       Exclusive_Read.

    o  Protected

       Starts a Read_Write transaction and reserves the table for
       Protected_Read.

    o  Shared

       Starts a Read_Write transaction and reserves the table for
       Shared_Read.

    Use one of the following options with the keyword Isolation_
    Level=[option] to specify the transaction isolation level:

    o  Read_Committed

    o  Repeatable_Read

    o  Serializable. Serializable is the default setting.

    Refer to the SET TRANSACTION statement in the Oracle Rdb SQL
    Reference Manual for a complete description of the transaction
    isolation levels.

    Specify the wait setting by using one of the following keywords:

    o  Wait

       Waits indefinitely for a locked resource to become available.
       Wait is the default behavior.

    o  Wait=n

       The value you supply for n is the transaction lock timeout
       interval. When you supply this value, Oracle Rdb waits n
       seconds before aborting the wait and the RMU Unload session.
       Specifying a wait timeout interval of zero is equivalent to
       specifying Nowait.

    o  Nowait

       Does not wait for a locked resource to become available.

4.19  –  Virtual Fields

    Virtual_Fields(=[No]Automatic,[No]Computed_By)
    Novirtual_Fields

    The Virtual_Fields qualifier unloads any AUTOMATIC or COMPUTED
    BY fields as real data. This qualifier permits the transfer of
    computed values to another application. It also permits unloading
    through a view that is a union of tables or that is comprised
    of columns from multiple tables. For example, if there are two
    tables, EMPLOYEES and RETIRED_EMPLOYEES, the view ALL_EMPLOYEES
    (a union of EMPLOYEES and RETIRED_EMPLOYEES tables) can be
    unloaded.

    The Novirtual_Fields qualifier is the default, which is
    equivalent to the Virtual_Fields=[Noautomatic,Nocomputed_By)
    qualifier.

    If you specify the Virtual_Fields qualifier without a keyword,
    all fields are unloaded, including COMPUTED BY and AUTOMATIC
    table columns, and calculated VIEW columns.

    If you specify the Virtual_Fields=(Automatic,Nocomputed_By)
    qualifier or the Virtual_Fields=Nocomputed_By qualifier, data
    is only unloaded from Automatic fields. If you specify the
    Virtual_Fields=(Noautomatic,Computed_By) qualifier or the
    Virtual_Fields=Noautomatic qualifier, data is only unloaded from
    Computed_By fields.

5  –  Usage Notes

    o  To use the RMU Unload command for a database, you must have
       the RMU$UNLOAD privilege in the root file access control
       list (ACL) for the database or the OpenVMS SYSPRV or BYPASS
       privilege. You must also have the SQL SELECT privilege to the
       table or view being unloaded.

    o  For tutorial information on the RMU Unload command, refer to
       the Oracle Rdb Guide to Database Design and Definition.

    o  Detected asynchronous prefetch should be enabled to achieve
       the best performance of this command. Beginning with Oracle
       Rdb V7.0, by default, detected asynchronous prefetch is
       enabled. You can determine the setting for your database by
       issuing the RMU Dump command with the Header qualifier.

       If detected asynchronous prefetch is disabled, and you do not
       want to enable it for the database, you can enable it for your
       Oracle RMU operations by defining the following logicals at
       the process level:

       $ DEFINE RDM$BIND_DAPF_ENABLED 1
       $ DEFINE RDM$BIND_DAPF_DEPTH_BUF_CNT P1

       P1 is a value between 10 and 20 percent of the user buffer
       count.

    o  You can unload a table from a database structured under
       one version of Oracle Rdb and load it into the same table
       of a database structured under another version of Oracle
       Rdb. For example, if you unload the EMPLOYEES table from
       a mf_personnel database created under Oracle Rdb V6.0, you
       can load the generated .unl file into an Oracle Rdb V7.0
       database. Likewise, if you unload the EMPLOYEES table from
       a mf_personnel database created under Oracle Rdb V7.0, you
       can load the generated .unl file into an Oracle Rdb V6.1
       database. This is true even for specially formatted binary
       files (created with the RMU Unload command without the Record_
       Definition qualifier). The earliest version into which you can
       load a .unl file from another version is Oracle Rdb V6.0.

    o  The Fields qualifier can be used with indirect file
       references. When you use the Fields qualifier with an indirect
       file reference in the field list, the referenced file is
       written to SYS$OUTPUT if you have used the DCL SET VERIFY
       command. See the Indirect-Command-Files help entry for more
       information.

    o  To view the contents of the specially structured .unl file
       created by the RMU Unload command, use the RMU Dump Export
       command.

    o  To preserve the null indicator in a load or unload operation,
       use the Null option with the Record_Definition qualifier.
       Using the Record_Definition qualifier without the Null option
       replaces all null values with zeros; this can cause unexpected
       results with computed-by columns.

    o  Oracle RMU does not allow you to unload a system table.

    o  The RMU Unload command recognizes character set information.
       When you unload a table, RMU Unload transfers information
       about the character set to the record definition file.

    o  When it creates the record definition file, the RMU Unload
       command preserves any lowercase characters in table and column
       names by allowing delimited identifiers. Delimited identifiers
       are user-supplied names enclosed within quotation marks ("").

       By default, RMU Unload changes any table or column (field)
       names that you specify to uppercase. To preserve lowercase
       characters, use delimited identifiers. That is, enclose the
       names within quotation marks. In the following example, RMU
       Unload preserves the uppercase and lowercase characters in
       "Last_Name" and "Employees":

       $  RMU/UNLOAD/FIELDS=("Last_name",FIRST_NAME) TEST "Employees" -
       _$ TEST.UNL

                                      NOTE

          The data dictionary does not preserve the distinction
          between uppercase and lowercase identifiers. If you use
          delimited identifiers, you must be careful to ensure that
          the record definition does not include objects with names
          that are duplicates except for the case. For example,
          the data dictionary considers the delimited identifiers
          "Employee_ID" and "EMPLOYEE_ID" to be the same name.

    o  Oracle RMU does not support the multischema naming convention
       and returns an error if you specify one. For example:

       $ RMU/UNLOAD CORPORATE_DATA ADMINISTRATION.PERSONNEL.EMPLOYEES -
       _$ OUTPUT.UNL
       %RMU-E-OUTFILDEL, Fatal error, output file deleted
       -RMU-F-RELNOTFND, Relation (ADMINISTRATION.PERSONNEL.EMPLOYEES) not found

       When using a multischema database, you must specify the SQL
       stored name for the database object.

       For example, to find the stored name that corresponds to the
       ADMINISTRATION.PERSONNEL.EMPLOYEES table in the corporate_data
       database, issue an SQL SHOW TABLE command, as follows:

       SQL> SHOW TABLE ADMINISTRATION.PERSONNEL.EMPLOYEES
       Information for table ADMINISTRATION.PERSONNEL.EMPLOYEES
           Stored name is EMPLOYEES
          .
          .
          .

       Then to unload the table, issue the following RMU Unload
       command:

       $ RMU/UNLOAD CORPORATE_DATA EMPLOYEES OUTPUT.UNL

    o  If the Transaction_Type qualifier is omitted, a Read_Only
       transaction is started against the database. This behavior is
       provided for backward compatibility with prior Rdb releases.
       If the Transaction_Type qualifier is specified without a
       transaction mode, the default value Automatic is used.

    o  If the database has snapshots disabled, Oracle Rdb defaults to
       a READ WRITE ISOLATION LEVEL SERIALIZABLE transaction. Locking
       may be reduced by specifying Transaction_Type=(Automatic), or
       Transaction_Type=(Shared,Isolation_Level=Read_Committed).

    o  If you use a synonym to represent a table or a view, the RMU
       Unload command translates the synonym to the base object
       and processes the data as though the base table or view had
       been named. This implies that the unload interchange files
       (.UNL) or record definition files (.RRD) that contain the
       table metadata will name the base table or view and not use
       the synonym name. If the metadata is used against a different
       database, you may need to use the Match_Name qualifier to
       override this name during the RMU load process.

6  –  Examples

    Example 1

    The following command unloads the EMPLOYEE_ID and LAST_NAME
    column values from the EMPLOYEES table of the mf_personnel
    database. The data is stored in names.unl.

    $ RMU/UNLOAD -
    _$ /FIELDS=(EMPLOYEE_ID, LAST_NAME) -
    _$ MF_PERSONNEL EMPLOYEES NAMES.UNL
    %RMU-I-DATRECUNL, 100 data records unloaded.

    Example 2

    The following command unloads the EMPLOYEES table from the
    mf_personnel database and places the data in the RMS file,
    names.unl. The names.rrd file contains the record structure
    definitions for the data in names.unl.

    $ RMU/UNLOAD/RECORD_DEFINITION=FILE=NAMES.RRD MF_PERSONNEL -
    _$ EMPLOYEES NAMES.UNL
    %RMU-I-DATRECUNL, 100 data records unloaded.

    Example 3

    The following command unloads the EMPLOYEE_ID and LAST_NAME
    column values from the EMPLOYEES table of the mf_personnel
    database and accepts the default values for delimiters, as shown
    by viewing the names.unl file:

    $ RMU/UNLOAD/FIELDS=(EMPLOYEE_ID, LAST_NAME) -
    -$ /RECORD_DEFINITION=(FILE=NAMES, FORMAT=DELIMITED_TEXT) -
    -$ MF_PERSONNEL EMPLOYEES NAMES.UNL
    %RMU-I-DATRECUNL, 100 data records unloaded.
    $ !
    $ ! TYPE the names.unl file to see the effect of the RMU Unload
    $ ! command.
    $ !
    $ TYPE NAMES.UNL

    "00164","Toliver       "
    "00165","Smith         "
    "00166","Dietrich      "
    "00167","Kilpatrick    "
    "00168","Nash          "
       .
       .
       .

    Example 4

    The following command unloads the EMPLOYEE_ID and LAST_NAME
    column values from the EMPLOYEES table of the mf_personnel
    database and specifies the asterisk (*)  character as the string
    to mark the beginning and end of each column (the prefix and
    suffix string):

    $ RMU/UNLOAD/FIELDS=(EMPLOYEE_ID, LAST_NAME) -
    _$ /RECORD_DEFINITION=(FILE=NAMES, -
    _$ FORMAT=DELIMITED_TEXT, SUFFIX="*", -
    _$ PREFIX="*") -
    _$ MF_PERSONNEL EMPLOYEES NAMES.UNL
    %RMU-I-DATRECUNL, 100 data records unloaded.
    $ !
    $ ! TYPE the names.unl file to see the effect of the RMU Unload
    $ ! command.
    $ !
    $ TYPE NAMES.UNL
    *00164*,*Toliver       *
    *00165*,*Smith         *
    *00166*,*Dietrich      *
    *00167*,*Kilpatrick    *
    *00168*,*Nash          *
    *00169*,*Gray          *
    *00170*,*Wood          *
    *00171*,*D'Amico       *
       .
       .
       .

    Example 5

    The following command unloads all column values from the
    EMPLOYEES table of the mf_personnel database, and specifies the
    Format=Text option of the Record_Definition qualifier. Oracle RMU
    will convert all the data to printable text, as can be seen by
    viewing the text_output.unl file:

    $ RMU/UNLOAD/RECORD_DEFINITION=(FILE=TEXT_RECORD,FORMAT=TEXT) -
    _$ MF_PERSONNEL EMPLOYEES TEXT_OUTPUT
    %RMU-I-DATRECUNL, 100 data records unloaded.
    $ !
    $ ! TYPE the text_output.unl file to see the effect of the RMU Unload
    $ ! command.
    $ !
    $ TYPE TEXT_OUTPUT.UNL
    00164Toliver       Alvin     A146 Parnell Place
    Chocorua            NH03817M19470328000000001
    00165Smith         Terry     D120 Tenby Dr.
    Chocorua            NH03817M19540515000000002
    00166Dietrich      Rick       19 Union Square
    Boscawen            NH03301M19540320000000001
       .
       .
       .

    Example 6

    The following command unloads the EMPLOYEE_ID and LAST_NAME
    column values from the EMPLOYEES table of the mf_personnel
    database and requests that statistics be displayed on the
    terminal at 2-second intervals:

    $ RMU/UNLOAD/FIELDS=(EMPLOYEE_ID, LAST_NAME)   -
    _$ /STATISTICS_INTERVAL=2             -
    _$ MF_PERSONNEL EMPLOYEES NAMES.UNL

    Example 7

    The following example unloads a subset of data from the EMPLOYEES
    table, using the following steps:

    1. Create a temporary view on the EMPLOYEES table that includes
       only employees who live in Massachusetts.

    2. Use an RMU Unload command to unload the data from this view.

    3. Delete the temporary view.

    $ SQL
    SQL> ATTACH 'FILENAME MF_PERSONNEL';
    SQL> CREATE VIEW MA_EMPLOYEES
    cont>       (EMPLOYEE_ID,
    cont>        LAST_NAME,
    cont>        FIRST_NAME,
    cont>        MIDDLE_INITIAL,
    cont>        STATE,
    cont>        STATUS_CODE)
    cont>  AS SELECT
    cont>        E.EMPLOYEE_ID,
    cont>        E.LAST_NAME,
    cont>        E.FIRST_NAME,
    cont>        E.MIDDLE_INITIAL,
    cont>        E.STATE,
    cont>        E.STATUS_CODE
    cont>     FROM EMPLOYEES E
    cont>     WHERE E.STATE='MA';
    SQL> COMMIT;
    SQL> EXIT;

    $ RMU/UNLOAD/RECORD_DEFINITION=(FILE=MA_EMPLOYEES,FORMAT=DELIMITED_TEXT) -
    _$ MF_PERSONNEL MA_EMPLOYEES MA_EMPLOYEES.UNL
    %RMU-I-DATRECUNL, 9 data records unloaded.

    $ SQL
    SQL> ATTACH 'FILENAME MF_PERSONNEL';
    SQL> DROP VIEW MA_EMPLOYEES;
    SQL> COMMIT;

    Example 8

    The following example shows that null values in blank columns
    are not preserved unless the Null option is specified with the
    Delimited_Text option of the Record_Definition qualifier:

    $ SQL
    SQL> ATTACH 'FILENAME MF_PERSONNEL';
    SQL> --
    SQL> -- Create the NULL_DATE table:
    SQL> CREATE TABLE NULL_DATE
    cont> (COL1 VARCHAR(5),
    cont>  DATE1 DATE,
    cont>  COL2 VARCHAR(5));
    SQL> --
    SQL> -- Store a row that does not include a value for the DATE1
    SQL> -- column of the NULL_DATE table:
    SQL> INSERT INTO NULL_DATE
    cont>            (COL1, COL2)
    cont>    VALUES ('first','last');
    1 row inserted
    SQL> --
    SQL> COMMIT;
    SQL> --
    SQL> -- The previous SQL INSERT statement causes a null value to
    SQL> -- be stored in NULL_DATE:
    SQL> SELECT * FROM NULL_DATE;
     COL1    DATE1                     COL2
     first   NULL                      last
    1 row selected
    SQL> --
    SQL> DISCONNECT DEFAULT;
    SQL> EXIT;
    $ !
    $ ! In the following RMU Unload command, the Record_Definition
    $ ! qualifier is used to unload the row with the NULL value, but
    $ ! the Null option is not specified:
    $ RMU/UNLOAD/RECORD_DEFINITION=(FILE=NULL_DATE,FORMAT=DELIMITED_TEXT) -
    _$  MF_PERSONNEL NULL_DATE NULL_DATE
    %RMU-I-DATRECUNL, 1 data records unloaded.
    $ !
    $ ! The null_date.unl file created by the previous unload
    $ ! operation does not preserve the NULL value in the DATE1 column.
    $ ! Instead, the Oracle Rdb default date value is used:
    $ TYPE NULL_DATE.UNL
    "first","1858111700000000","last"
    $ !
    $ ! This time, unload the row in NULL_DATE with the Null option to
    $ ! the Record_Definition qualifier:
    $ RMU/UNLOAD MF_PERSONNEL NULL_DATE NULL_DATE -
    _$ /RECORD_DEFINITION=(FILE=NULL_DATE.RRD, FORMAT=DELIMITED_TEXT, NULL="*")
    %RMU-I-DATRECUNL,   1 data records unloaded.
    $ !
    $ TYPE NULL_DATE.UNL
    "first",*,"last "
    $ SQL
    SQL> ATTACH 'FILENAME MF_PERSONNEL';
    SQL> --
    SQL> -- Delete the existing row from NULL_DATE:
    SQL> DELETE FROM NULL_DATE;
    1 row deleted
    SQL> --
    SQL> COMMIT;
    SQL> EXIT;
    $ !
    $ ! Load the row that was unloaded back into the table,
    $ ! using the null_date.unl file created by the
    $ ! previous RMU Unload command:
    $ RMU/LOAD MF_PERSONNEL /RECORD_DEFINITION=(FILE=NULL_DATE.RRD, -
    _$ FORMAT=DELIMITED_TEXT, NULL="*") NULL_DATE NULL_DATE
    %RMU-I-DATRECREAD,  1 data records read from input file.
    %RMU-I-DATRECSTO, 1 data records stored.
    $ !
    $ SQL
    SQL> ATTACH 'FILENAME MF_PERSONNEL';
    SQL> --
    SQL> -- Display the row stored in NULL_DATE.
    SQL> -- The NULL value stored in the data row
    SQL> -- was preserved by the load and unload operations:
    SQL> SELECT * FROM NULL_DATE;
     COL1    DATE1                     COL2
     first   NULL                      last
    1 row selected

    Example 9

    The following example demonstrates the use of the Null="" option
    of the Record_Definition qualifier to signal to Oracle RMU that
    any data that is an empty string in the .unl file (as represented
    by two commas with no space separating them) should have the
    corresponding column in the database flagged as NULL.

    The first part of this example shows the contents of the .unl
    file and the RMU Load command used to load the .unl file. The
    terminator for each record in the .unl file is the number sign
    (#).  The second part of this example unloads unloads the data
    and specifies that any columns that are flagged as NULL should be
    represented in the output file with an asterisk.

    "90021","ABUSHAKRA","CAROLINE","A","5 CIRCLE STREET",,
    "CHELMSFORD", "MA", "02184", "1960061400000000"#
    "90015","BRADFORD","LEO","B","4 PLACE STREET",, "NASHUA","NH",
    "03030", "1949051800000000"#
    $ !
    $ RMU/LOAD/FIELDS=(EMPLOYEE_ID, LAST_NAME, FIRST_NAME, -
    _$ MIDDLE_INITIAL, ADDRESS_DATA_1, ADDRESS_DATA_2,  -
    _$ CITY, STATE, POSTAL_CODE, BIRTHDAY) -
    _$ /RECORD_DEFINITION=(FILE= EMPLOYEES.RRD, -
    _$ FORMAT=DELIMITED_TEXT, -
    _$ TERMINATOR="#", -
    _$ NULL="") -
    _$ MF_PERSONNEL EMPLOYEES EMPLOYEES.UNL
    %RMU-I-DATRECREAD,  2 data records read from input file.
    %RMU-I-DATRECSTO,   2 data records stored.
    $ !
    $ ! Unload this data first without specifying the Null option:
    $ RMU/UNLOAD/FIELDS=(EMPLOYEE_ID, LAST_NAME, FIRST_NAME, -
    _$ MIDDLE_INITIAL, ADDRESS_DATA_1, ADDRESS_DATA_2,  -
    _$ CITY, STATE, POSTAL_CODE, BIRTHDAY) -
    _$ /RECORD_DEFINITION=(FILE= EMPLOYEES.RRD, -
    _$ FORMAT=DELIMITED_TEXT, -
    _$ TERMINATOR="#") -
    _$ MF_PERSONNEL EMPLOYEES EMPLOYEES.UNL
    %RMU-I-DATRECUNL,   102 data records unloaded.
    $ !
    $ ! The ADDRESS_DATA_2 field appears as a quoted string:
    $ TYPE EMPLOYEES.UNL
       .
       .
       .
    "90021","ABUSHAKRA     ","CAROLINE  ","A","5 CIRCLE STREET        ","
                ","CHELMSFORD          ","MA","02184","1960061400000000"#
    $ !
    $ ! Now unload the data with the Null option specified:
    $ RMU/UNLOAD/FIELDS=(EMPLOYEE_ID, LAST_NAME, FIRST_NAME, -
    _$ MIDDLE_INITIAL, ADDRESS_DATA_1, ADDRESS_DATA_2,  -
    _$ CITY, STATE, POSTAL_CODE, BIRTHDAY) -
    _$ /RECORD_DEFINITION=(FILE= EMPLOYEES.RRD, -
    _$ FORMAT=DELIMITED_TEXT, -
    _$ TERMINATOR="#", -
    _$ NULL="*") -
    _$ MF_PERSONNEL EMPLOYEES EMPLOYEES.UNL
    %RMU-I-DATRECUNL,   102 data records unloaded.
    $ !
    $ ! The value for ADDRESS_DATA_2 appears as an asterisk:
    $ !
    $ TYPE EMPLOYEES.UNL
       .
       .
       .
    "90021","ABUSHAKRA     ","CAROLINE  ","A","5 CIRCLE STREET       ",*,
    "CHELMSFORD          ","MA","02184","1960061400000000"#

    Example 10

    The following example specifies a transaction for the RMU Unload
    command equivalent to the SQL command SET TRANSACTION READ WRITE
    WAIT 36 RESERVING table1 FOR SHARED READ;

    $ RMU/UNLOAD-
        /TRANSACTION_TYPE=(SHARED,ISOLATION=REPEAT,WAIT=36)-
        SAMPLE.RDB-
        TABLE1-
        TABLE.DAT

    Example 11

    The following example specifies the options that were the default
    transaction style in prior releases.

    $ RMU/UNLOAD-
        /TRANSACTION_TYPE=(READ_ONLY,ISOLATION_LEVEL=SERIALIZABLE)-
        SAMPLE.RDB-
        TABLE1-
        TABLE1.DAT

    Example 12

    If the database currently has snapshots deferred, it may be more
    efficient to start a read-write transaction with isolation level
    read committed. This allows the transaction to start immediately
    (a read-only transaction may stall), and the selected isolation
    level keeps row locking to a minimum.

    $ RMU/UNLOAD-
        /TRANSACTION_TYPE=(SHARED_READ,ISOLATION=READ_COMMITTED)-
        SAMPLE.RDB-
        TABLE1-
        TABLE1.DAT

    Using a transaction type of automatic adapts to different
    database settings.

    $ RMU/UNLOAD-
        /TRANSACTION_TYPE=(AUTOMATIC)-
        SAMPLE.RDB-
        TABLE1-
        TABLE1.DAT

    Example 13

    The following example shows the output from the flags STRATEGY
    and ITEM_LIST which indicates that the Optimize qualifier
    specified that sequential access be used, and also that Total_
    Time is used as the default optimizer preference.

    $ DEFINE RDMS$SET_FLAGS "STRATEGY,ITEM_LIST"
    $ RMU/UNLOAD/OPTIMIZE=SEQUENTIAL_ACCESS PERSONNEL EMPLOYEES E.DAT
       .
       .
       .
    ~H Request Information Item List: (len=11)
    0000 (00000) RDB$K_SET_REQ_OPT_PREF "0"
    0005 (00005) RDB$K_SET_REQ_OPT_SEQ "1"
    000A (00010) RDB$K_INFO_END
    Get     Retrieval sequentially of relation EMPLOYEES
    %RMU-I-DATRECUNL,   100 data records unloaded.

    Example 14

    AUTOMATIC columns are evaluated during INSERT and UPDATE
    operations for a table; for instance, they may record the
    timestamp for the last operation. If the table is being
    reorganized, it may be necessary to unload the data and reload it
    after the storage map and indexes for the table are re-created,
    yet the old auditing data must remain the same.

    Normally, the RMU Unload command does not unload columns marked
    as AUTOMATIC; you must use the Virtual_Fields qualifier with the
    keyword Automatic to request this action.

    $ rmu/unload/virtual_fields=(automatic) payroll_db people people.unl

    Following the restructure of the database, the data can be
    reloaded. If the target columns are also defined as AUTOMATIC,
    then the RMU Load process will not write to those columns. You
    must use the Virtual_Fields qualifier with the keyword Automatic
    to request this action.

    $ rmu/load/virtual_fields=(automatic) payroll_db people people.unl

    Example 15

    This example shows the action of the Delete_Rows qualifier.
    First, SQL is used to display the count of the rows in the table.
    The file PEOPLE.COLUMNS is verified (written to SYS$OUTPUT) by
    the RMU Unload command.

    $ define sql$database db$:scratch
    $ sql$ select count (*) from people;

             100
    1 row selected
    $ rmu/unload/fields="@people.columns" -
        sql$database -
        /record_definition=(file:people,format:delimited) -
        /delete_rows -
        people -
        people2.dat
      EMPLOYEE_ID
      LAST_NAME
      FIRST_NAME
      MIDDLE_INITIAL
      SEX
      BIRTHDAY
    %RMU-I-DATRECERA,   100 data records erased.
    %RMU-I-DATRECUNL,   100 data records unloaded.

    A subsequent query shows that the rows have been deleted.

    $ sql$ select count (*) from people;

               0
    1 row selected

    Example 16

    The following example shows the output from the RMU Unload
    command options for XML support. The two files shown in the
    example are created by this RMU Unload command:

    $ rmu/unload -
        /record_def=(format=xml,file=work_status) -
        mf_personnel -
        work_status -
        work_status.xml

    Output WORK_STATUS.DTD file

    <?xml version="1.0"?>
    <!-- RMU Unload for Oracle Rdb V7.1-00 -->
    <!-- Generated: 16-MAR-2001 22:26:47.30 -->

    <!ELEMENT WORK_STATUS (RMU_ROW*)>
    <!ELEMENT RMU_ROW (
     STATUS_CODE,
     STATUS_NAME,
     STATUS_TYPE
    )>
    <!ELEMENT STATUS_CODE (#PCDATA)>
    <!ELEMENT STATUS_NAME (#PCDATA)>
    <!ELEMENT STATUS_TYPE (#PCDATA)>
    <!ELEMENT NULL (EMPTY)>

    Output WORK_STATUS.XML file

    <?xml version="1.0"?>
    <!-- RMU Unload for Oracle Rdb V7.1-00 -->
    <!-- Generated: 16-MAR-2001 22:26:47.85 -->

    <!DOCTYPE WORK_STATUS SYSTEM "work_status.dtd">

    <WORK_STATUS>
     <RMU_ROW>
      <STATUS_CODE>0</STATUS_CODE>
      <STATUS_NAME>INACTIVE</STATUS_NAME>
     <STATUS_TYPE>RECORD EXPIRED</STATUS_TYPE>
     </RMU_ROW>
     <RMU_ROW>
      <STATUS_CODE>1</STATUS_CODE>
      <STATUS_NAME>ACTIVE  </STATUS_NAME>
      <STATUS_TYPE>FULL TIME     </STATUS_TYPE>
     </RMU_ROW>
     <RMU_ROW>
      <STATUS_CODE>2</STATUS_CODE>
      <STATUS_NAME>ACTIVE  </STATUS_NAME>
      <STATUS_TYPE>PART TIME     </STATUS_TYPE>
     </RMU_ROW>
    </WORK_STATUS>

    <!-- 3 rows unloaded -->

    Example 17

    The following example shows that if the Flush=On_Commit qualifier
    is specified, the value for the Commit_Every qualifier must be
    equal to or a multiple of the Row_Count value so the commits
    of unload transactions occur after the internal RMS buffers are
    flushed to the unload file. This prevents loss of data if an
    error occurs.

    $RMU/UNLOAD/ROW_COUNT=5/COMMIT_EVERY=2/FLUSH=ON_COMMIT MF_PERSONNEL -
    _$ EMPLOYEES EMPLOYEES
    %RMU-F-DELROWCOM, For DELETE_ROWS or FLUSH=ON_COMMIT the COMMIT_EVERY value must
     equal or be a multiple of the ROW_COUNT value.
    The COMMIT_EVERY value of 2 is not equal to or a multiple of the ROW_COUNT value
     of 5.
    %RMU-F-FTL_UNL, Fatal error for UNLOAD operation at 27-Oct-2005 08:55:14.06

    Example 18

    The following examples show that the unload file and record
    definition files are not deleted on error if the Noerror_Delete
    qualifier is specified and that these files are deleted on error
    if the Error_Delete qualifier is specified. If the unload file is
    empty when the error occurs, it will be deleted.

    $RMU/UNLOAD/NOERROR_DELETE/ROW_ACOUNT=50/COMMIT_EVERY=50 MF_PERSONNEL -
    _$ EMPLOYEES EMPLOYEES.UNL

    %RMU-E-OUTFILNOTDEL, Fatal error, the output file is not deleted but may not
    be useable,
    50 records have been unloaded.
    -COSI-F-WRITERR, write error
    -RMS-F-FUL, device full  (insufficient space for allocation)

    $RMU/UNLOAD/ERROR_DELETE/ROW_COUNT=50/COMMIT_EVERY=50 MF_PERSONNEL -
    _$ EMPLOYEES EMPLOYEES.UNL

    %RMU-E-OUTFILDEL, Fatal error, output file deleted
    -COSI-F-WRITERR, write error
    -RMS-F-FUL, device full (insufficient space for allocation)

    Example 19

    The following example shows the FORMAT=CONTROL option. This
    command creates a file EMP.CTL (the SQL*Loader control file)
    and EMPLOYEES.DAT in a portable format to be loaded.

    $ RMU/UNLOAD/RECORD_DEFINITION=(FORMAT=CONTROL,FILE=EMP) -
        SQL$DATABASE -
        EMPLOYEES -
        EMPLOYEES

    Example 20

    The following shows an example of using the COMPRESSION qualifier
    with the RMU Unload command.

    $ RMU/UNLOAD/COMPRESS=LZW/DEBUG=TRACE COMPLETE_WORKS COMPLETE_WORKS
    COMPLETE_WORKS
    Debug = TRACE
    Compression = LZW
    * Synonyms are not enabled
    Unloading Blob columns.
    Row_Count = 500
    Message buffer: Len: 54524
    Message buffer: Sze: 109, Cnt: 500, Use: 31 Flg: 00000000
    ** compress data: input 2700 output 981 deflate 64%
    ** compress TEXT_VERSION : input 4454499 output 1892097 deflate 58%
    ** compress PDF_VERSION : input 274975 output 317560 deflate -15%
    %RMU-I-DATRECUNL,   30 data records unloaded.

    Example 21

    The following shows an example of using the COMPRESSION qualifier
    with RMU Unload and using the EXCLUDE_LIST option to avoid
    attempting to compress data that does not compress.

    $ RMU/UNLAOD/COMPRESS=(LZW,EXCLUDE_LIST:PDF_VERSION)/DEBUG=TRACE COMPLETE_WORKS
    COMPLETE_WORKS COMPLETE_WORKS
    Debug = TRACE
    Compression = LZW
    Exclude_List:
            Exclude column PDF_VERSION
    * Synonyms are not enabled
    Unloading Blob columns.
    Row_Count = 500
    Message buffer: Len: 54524
    Message buffer: Sze: 109, Cnt: 500, Use: 31 Flg: 00000000
    ** compress data: input 2700 output 981 deflate 64%
    ** compress TEXT_VERSION : input 4454499 output 1892097 deflate 58%
    %RMU-I-DATRECUNL,   30 data records unloaded.
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