Data Stream

The Loader exports the data from databases into data streams or imports data from data streams into databases. The data can be transformed in this process.

A range of syntax elements are available for describing the data stream. These syntax elements can be used in the export and import commands.

Syntax

In addition to the name of the data stream, you can also specify the data carrier type, you can transfer formats and, if necessary, include other information to describe the data stream in more detail.

·         You enter the keyword OUTSTREAM to specify that the data is to be exported from a MaxDB database instance to a data stream.

·         You enter the keyword INSTREAM to specify that the data is to be imported from a data stream to a MaxDB database instance.

The following syntax elements are used in the Loader syntax:

<outstream_columnformat_spec> ::= OUTSTREAM [<mediumtype_spec>] '<stream_name>' [<column_dataformat_spec>] [<start_spec>]
<instream_columnformat_spec>  ::=  INSTREAM [<mediumtype_spec>] '<stream_name>' [<column_dataformat_spec>] [<start_spec>]

<outstream_tableformat_spec>  ::= OUTSTREAM [<mediumtype_spec>] '<stream_name>' [<table_dataformat_spec>]
<instream_tableformat_spec>   ::=  INSTREAM [<mediumtype_spec>] '<stream_name>' [<table_dataformat_spec>]

It may be necessary to specify the format of the data stream (CSV, DDL, FWV [BINARY], PAGES, RECORDS).

<outstream_csv_spec>     ::= OUTSTREAM [<mediumtype_spec>] '<stream_name>' [CSV [<csv_format_spec> ...]] [<start_spec>]
<instream_csv_spec>      ::=  INSTREAM [<mediumtype_spec>] '<stream_name>' [CSV [<csv_format_spec> ...]] [<start_spec>]

<outstream_ddl_spec>          ::= OUTSTREAM [<mediumtype_spec>] '<stream_name>' [DDL]
<instream_ddl_spec>           ::= INSTREAM [<mediumtype_spec>] '<stream_name>' [DDL]

<outstream_fwv_spec>     ::= OUTSTREAM [<mediumtype_spec>] '<stream_name>' FWV [<fwv_format_spec> ...] [<start_spec>]
<instream_fwv_spec>      ::=  INSTREAM [<mediumtype_spec>] '<stream_name>' FWV [<fwv_format_spec> ...] [<start_spec>]

<outstream_pages_spec>   ::= OUTSTREAM [<mediumtype_spec>] '<stream_name>' [PAGES]
<instream_pages_spec>    ::=  INSTREAM [<mediumtype_spec>] '<stream_name>' [PAGES]

<outstream_records_spec> ::= OUTSTREAM [<mediumtype_spec>] '<stream_name>' RECORDS [<records_format_spec>]
<instream_records_spec>  ::=  INSTREAM [<mediumtype_spec>] '<stream_name>' RECORDS [<records_format_spec>]

See also:

CSV, FWV, FWV BINARY, PAGES, RECORDS

If LONG values are being handled, you need to note some syntax rules.

<outstream_lob_spec>   ::= exporting LONG values
<instream_lob_spec>    ::=
importing LONG values

<mediumtype_spec>

Data Carrier Type

<stream_name>

Name and path of the data stream

CSV

CSV (Comma Separated Values) is a format for CHAR data in which a data line must at least be long enough to represent the data. The assignment of a data field of the data stream to a column in the table is determined by the position specification.

FWV

FWV (Fixed Width Values) is a format for plain text values in which a data line in the data stream corresponds to a data record. The assignment between data fields in the data stream and table columns is determined by the position specification.

FWV BINARY

FWV BINARY (Fixed Width Values BINARY) is a format for binary values in which the data fields all have the same fixed length. The assignment between data fields in the data stream and table columns is determined by the position specification. Unlike the FWV format, a data record does not end with an additional line break.

PAGES

Format that specifies that the application data is stored in pages

RECORDS

Database format

DDL

DDL (Data Definition Language) is a format that can be specified for a data stream with database catalog data

<column_dataformat_spec>
<table_dataformat_spec>

<csv_format_spec>
<fwv_format_spec>
<records_format_spec>

Data format

<start_spec>

  START <unsigned_integer> [MAXROWS]
| START <unsigned_integer> [MAXRECORDS]
| START <unsigned_integer> <unsigned_integer>

Import: the area determined by the start_spec is imported from the data stream.

Export: the area determined by the start_spec is exported from a table.

unsigned_integer: you can specify the starting point of the area (START <unsigned_integer> [MAXROWS] or START <unsigned_integer> [MAXRECORDS]) or the upper and lower limits for the area (<unsigned_integer> <unsigned_integer>).

See the SQL Reference Manual, Unsigned Integer (unsigned_integer)

Examples

IMPORT TABLE hotel.room 
DATA INSTREAM 'room_csv.data'

The application data (DATA) stored in the room_csv.data data stream is imported (IMPORT) to (INSTREAM) the ROOM table in the HOTEL schema. The data carrier type for the room_csv.data data stream is a file (FILE, default value). The format of the data stream is CSV (default value).

Loader Tutorial, Exporting, Importing

Explanation

The keywords CATALOG, DATA, CONFIGURATION and PACKAGE are used in the commands for exporting and importing to differentiate by the type of data that is exported or imported.

<catalog_outstream_spec>

CATALOG <outstream_ddl_spec>

<catalog_instream_spec>

CATALOG <instream_ddl_spec>

Data streams for the application data’s database catalog information

<data_outstream_column_spec>

DATA <outstream_columnformat_spec> [<export_lobcolumn_spec>...]

<data_outstream_part_spec>

DATA <outstream_tableformat_spec>

<data_outstream_table_spec>

  <data_outstream_part_spec>
| <data_oustream_column_spec>

<data_instream_column_spec>

DATA <instream_tableformat_spec>

<data_instream_columns_spec>

DATA <instream_columnformat_spec>
  [<
import_column_spec>...
  <
import_lobcolumn_spec>...]
  [<usage_spec>]
<usage_spec> ::=
performance improvement in the IMPORT TABLE

<data_instream_part_spec>

DATA <instream_tableformat_spec>

<data_instream_table_spec>

  <data_instream_part_spec>
| <data_instream_columns_spec>

Data streams for the application data

<configuration_spec>

CONFIGURATION <instream_csv_spec>

The application data of selected tables can be excluded from the export or import

<package_spec>

PACKAGE <outstream_csv_spec>

Data stream with the entries from the TRANSFORMATIONMODEL system table (see also: Additional Log Functions (package_spec))

See also:

Exporting: Commands

Importing: Commands

Data

Data Format

Data Types

Exporting and Importing Using Backup Tools from Other Providers