The loader has several operating modes distinguished by command line flags:
.TP
\fB\-d\fR
Drops the database table before creating a new table with the data in the Shape file.
.TP
\fB\-a\fR
Appends data from the Shape file into the database table. Note that to use this option to load multiple files, the files must have the same attributes and same data types.
.TP
\fB\-c\fR
Creates a new table and populates it from the Shape file. This is the default mode.
Use the PostgreSQL "dump" format for the output data. This can be combined with -d, -a and -c and is much faster to load than the default "insert" SQL format. Use this for very large data sets.