The material in this chapter supplements Chapter 2 of the Databridge Client Administrator's Guide. Most of that material applies equally to the Flat File Client. This chapter simply points out the differences between two clients. As mentioned previously, the Flat File Client uses Client control tables in exactly the same way as relational database clients do. These control tables are common to all clients and they have exactly the same layout. See Databridge Client Control Tables in the Databridge Client Administrator's Guide for a complete description of these tables.
Before you clone a DMSII data source, you must create the Client control tables. Once they're created, you can populate them with DMSII information sent by the Databridge Engine and create the data files that will store your cloned data. The resulting data files are based on information from the Client control tables and any additional customizations you make.
To customize how DMSII data sets get mapped to their corresponding relational database tables, you can use the Client Configurator or you can write user scripts in SQL. The Client Configurator is compatible with command-line operations and can help make reorganizations easier to handle. For more information on the Client Configurator, go to the Help menu in the Client Console. Writing and testing user scripts is typically time-consuming and requires a bit of trial and error. For instructions, see Customizing with User Scripts in the Databridge Client Administrator's Guide.
Creating Client Control Tables
The material in the corresponding section in Chapter 2 (Creating Client
Control Tables) of the Databridge Client Administrator's Guide applies
to the Flat File Client, except that the command line client has no
option and the configuration file parameter
use_nt_authen is not
supported. If you are using a Microsoft SQL database, you can use
integrated Windows Authentication when creating the ODBC data source.
Because it has no bulk loader, the Client does not need this option.
The Flat File Client has a
dbfixup program that updates your control
tables to the current version. It works exactly the way the relational
database clients do.
Defining a Data Source
Refer to the material in Chapter 2 of the Databridge Client Administrator's Guide, Defining a Data Source. All information applies to the Flat File Client except for the data table creation and index creation user scripts (these don't apply because no relational database tables are involved).
Client Administrator's Guide section on Decoding DMSII Dates, Times, and Date/Times
applies to the Flat File Client except for this: the dates are written
out using the format specified by the
span_date_format parameter in
[PCSpan] section of the client configuration file.
The Databridge Client Administrator's Guide section on Creating Indexes for Tables does not apply to the Flat File Client.
The Databridge Client Administrator's Guide section on Adding a Non DMSII Column applies to the Flat File Client; in fact it supports more types of external columns than the relational database clients do in order to remain compatible with DBSPAN. The table below shows the values for all the external column types supported by the Flat File Client.
The value for the Bit column in this table is equal to the value in the
dms_subtype column of the DATAITEMS Client control table. The exception
is bit 14, which results in a
dms_subtype of 0. Bits are numbered from
right to left; the right-most bit is 1.
|Bit||Value||User Column Name||Description|
|1||1||update_type||Database update type, as follows:
|2||2||update_time||Time the update was written to the flat file.|
|4||8||audit_ts||DMSII audit file timestamp. This column is set to NULL during the initial clone.
NOTE: You cannot use this bit at teh same time as bit 13.
|5||16||audit_filenum||Audit file number|
|6||32||audit_block||Audit block serial number (ABSN)|
|7||64||source_name||Data source name|
|8||128||source_id||Data source identifier as defined in the DATASOURCES Client control table|
|11||1024||update_type||Expanded database update type as follows:
0 for extract
1 for create
2 for delete
3 for modify
|12||2048||source_id||Data source identifier as defined in the DATASOURCES Client control table (key item)|
|13||4096||audit_ts||Expanded audit file time. This column contains the DMSII audit file timestamp
during updates and the starting time of the data extraction during extraction.
NOTE:You cannot use this bit at the same time as bit 4.
|14||8192||user_column1||Generic user column whose entry is left as NULL.|
|17||65536||create_time||Time when the record was created in the flat file (PC time).|
|18||131072||user_column2||Generic user column whose entry is left as NULL.|
|19||262144||user_column3||Generic user column whose entry is left as NULL.|
|20||524288||user_column4||Generic user column whose entry is left as NULL.|
|21||1048576||change_code||The one letter change code for an update A=Add, D=Delete, M=Modify|
|22||2097152||strnum||The structure number for the data set.|
|23||4194304||strname||The data set name.|
|24||8388608||rectype||The record type for variable format data sets.|
|25||16777216||modflag||A flag that indicates if an update is part of a MODIFY BI/AI pair. A value of 1 for an ADD or a DELETE, indicates that the ADD was originally the AI or DELETE was originally the BI of a MODIFY BI/AI pair.|
|26||33554432||mode||The mode of the data set as stored in the `ds_mode` column of the DATASETS Client control table. 0=CLONE, 1=FIXUP, 2=UPDATE.|
|27||67108864||fmt_level||The format level for the data set.|
|28||134217728||audit_seg||The segment number of the audit location within the audit file (audit_seg column in DATASETS Client control table)|
|29||268435456||audit_inx||The index of the audit location within the segment of the audit file (audit_inx column in DATASETS Client control table)|
|30||536870912||stacknbr||The stack number of the corresponding task on the MCP.|
Values for All the Externals Column Types Supported by the Flat File Client
The Process Command
process command is the main command of the Databridge Flat File
Client. It creates the flat files for all data set tables whose active
column is 1 in the corresponding entries of the DATASETS Client control
table. Since the
define command initializes the
ds_mode column, all
the selected data sets are cloned the first time you run a
If you do not select specific data sets in the data set global mapping script, the Databridge Client automatically clones all data sets except for remaps, the restart data set, and the global data set. This operation may take a very long time and require a lot of disk space.
You can schedule the
process command to update the Databridge flat
files. The schedule becomes effective after you run the
command for the first time. For more information, see Scheduling Updates
in the Databridge Client Administrator's Guide.
To create the Databridge extract, fixup, and update files using the
command line Flat File Client's
process command, you must first make
sure that the current directory is set to the working directory you
created for this data source. If you start the run from the Client
Console, you do not have to deal with such details. You simply initiate
process command using the Data Source menu.
The remainder of the material in The Process Command
section of the Databridge Client Administrator's Guide applies to the
Flat File Client. You can control the locations of the flat files using
[PCSpan] section parameters
update_dir. By default, all files are written to the working
directory. If you want to keep them separate, you can specify different
directories such as "extracts", "fixups" and "updates". The names
normally will be relative to the working directory. Thus in the above
example, the client would create three subdirectories in the working
directory. The files will have similar names, which can be made to
include some metadata by using the file name mask. See the
filename_mask parameter described in Appendix A.
The Clone Command
Refer to The Clone Command in Chapter 3: Cloning a DMSII Database of the Databridge Client Administrator's Guide for more information.