Piping blob data
Blob data is data that is a binary large-object such as a
Microsoft Word document or an Excel spreadsheet. A data pipeline can
pipe columns containing blob data.
The name of the datatype that supports blob data varies by DBMS.
The following table shows some examples.
|
DBMS |
Datatypes that support blob data |
|---|---|
|
SAP SQL Anywhere |
LONG BINARY, LONG VARCHAR (if more than 32 |
|
SAP Adaptive Server Enterprise |
IMAGE, TEXT |
|
Microsoft SQL Server |
IMAGE, TEXT |
|
Oracle |
RAW, LONG RAW |
|
Informix |
BYTE, TEXT |
For information about the datatype that supports blob data in
your DBMS, see your DBMS documentation.
Adding blob columns to a pipeline
definition
When you select data to pipe, you cannot select a blob column as
part of the data source because blobs cannot be handled in a SELECT
statement. After the pipeline definition is created, you add blob
columns, one at a time, to the definition.
To add a blob column to a pipeline definition
-
Select Design>Database Blob from the menu bar.
If the Database Blob menu item is disabled
The Database Blob menu item is disabled if the pipeline
definition does not contain a unique key for at least one source
table, or if the pipeline operation is Refresh, Append, or
Update and the destination table has no blob columns.The Database Binary/Text Large Object dialog box displays.
The Table box has a drop-down list of tables in the pipeline
source that have a primary key and contain blob columns. -
In the Table box, select the table that contains the blob
column you want to add to the pipeline definition.For example, in the PB Demo DB, the ole table contains a
blob column named Object with the large binary datatype. -
In the Large Binary/Text Column box, select a column that
has a blob datatype. -
In the Destination Column box, change the name of the
destination column for the blob if you want to. -
If you want to add the column and see changes you make
without closing the dialog box, click Apply after each
change.When you have specified the blob source and destination as
needed, click OK.
To edit the source or destination name of the blob column in
the pipeline definition
-
Display the blob column’s pop-up menu and select
Properties.
To delete a blob column from the pipeline definition
-
Display the blob column’s pop-up menu and select
Clear.
Executing a pipeline with blob
columns
After you have completed the pipeline definition by adding one
or more blob columns, you can execute the pipeline. When you do, rows
are piped a block at a time, depending on the Commit value. For a
given block, Row 1 is inserted, then Row 1 is updated with Blob 1,
then Row 1 is updated with Blob 2, and so on. Then Row 2 is inserted,
and so on until the block is complete.
If a row is not successfully piped, the blob is not piped. Blob
errors display, but the blob itself does not display. When you correct
a row and execute the pipeline, the pipeline pipes the blob.