Exclude filters 1. To see which column names you can filter on, use dmlist a.fits cols to display the columns in the main block of file a.fits. The interpretation is a little different depending on whether the table column has integer or real data type. Filtering is a little more restricted with character string columns. The comparison is case-sensitive.
Table filtering on columns with bit data type Columns with bit data type are a special case.
Suppose for simplicity you instead have a status column with only 6 bits, and wish to accept rows with the 3rd bit from the end set and the end bit equal to zero.