RECORD FILTERS

By default, MARC Review and MARC Global jobs run on all records in a file. You can use Filters to restrict the input or output to a range of records.

INPUT FILTERS

Set up an input filter if you do not want to process the whole file.

For example, let's say your file contains 10,000 records. If you enter '1000' in the 'Stop processing at' box, MARC Review/MARC Global will stop processing once 1,000 records have been processed. This option might be useful if you are running MARC Review on a large database and want to quickly extract the first 1,000 records.

You can also use an input filter if you do not want to start processing at the first record in a file. For example, if you enter '1000' in the 'Start processing at' box, MARC Review/MARC Global will skip ahead to the 1,000 th record before starting your task.

Input filters can be used in both MARC Review and MARC Global.

If you enter a value for the 'Start At' number that is greater than the number of records in the file, nothing will be output; entering a value for the 'Stop At' number that is greater than the number of records in the file has no effect (ie. processing will go to the end of the file).

OUTPUT FILTERS

Set up an output filter if you want to generate a small sample of a larger file using MARC Review (output filters are ignored by MARC Global).

For example, if you have a file of 10,000 records, and want to create a sample of only 50 records, you could enter '200' in the 'Output only every' box. MARC Review/MARC Global would then process your entire file, but output only every 200th record (thus '200' is known as the 'record interval').

To activate an Output option you must both select the checkbox and enter a record interval.

To calculate the record interval, divide the number of records in your file by the number of records that you want to have in your sample. In this example that would be: 10000 / 50

However, note that output filters are applied AFTER any specified processing. Therefore, if you are running MARC Review and have specified a pattern that does not match every record in the file, any record interval will be applied to matching records only (not to all of the records in the file). In this case, the number of records that will be output will depend on the numbers of record that match your pattern(s), and not on the total number of records in the file.

Output filters can be used for both MARC Output and Text Output; however, for MARC Output, only the 'Matching records only' option will achieve the intended result if a pattern is specified.

If you enter a value for the record interval number that is greater than the number of records in the file, nothing will be output.

APPLY TAGLIST TO MARC OUTPUT

This option allows you to output a subset of tags from each record output during MARC Review. You could use it to create 'mini-MARC' records; for example, records that contain only a 001, 100, 245, and 260.

Currently in MARC Review, we specify a taglist on the Text output page, and these tags are then selected for output in whatever text format is selected.

When the option 'Apply taglist to MARC Output' is selected, the taglist on the Text Output page will also be applied to whatever MARC records are created. The MARC file(s) that is created will contain only the tags in the taglist.

Notes:

+ does not apply to MARC Global
+ the Text output type should be set to 'Custom'
+ a MARC Output file must be specified.

NOTES ABOUT FILTERS (and samples)

Be aware that when using filters, any MARC results will no longer represent the file that you started with.

When entering record numbers, do not enter commas: '1000' not '1,000'.

The input and output filters can be used at the same time. For example, you could set an input filter thats starts processing with record 2001 and stops processing at record 3000, then set an output filter to output only every 10th matching record.

Based on our record processing experience, we believe the best way for a library to communicate a sample of their records to another party is to send the whole database. If that's not practical, then at least run the MARC Analysis utility on your complete database and add that report to your sample.

phelp/helpiofilters.txt · Last modified: 2021/12/29 16:21 (external edit)
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