# *********************************************************************
#  Written by and copyright Carlo Strozzi <carlos@linux.it>.
#
#  union.txt: help text
#  Copyright (C) 2001 Carlo Strozzi <carlos@linux.it>
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                      NoSQL operator: union

Concatenates multiple NoSQL tables and prints them to STDOUT in
the form of one larger table. The input tables must all have the
same number of columns, i.e. they must be ``union compatible''.

Usage: union [options] table [table ...]

Options:
    --help (-h)
      Display this help text.

    --no-header (-N)
      Suppress the table header from output.

    --xargs (-a) 'table'
      Read the table header from 'table'. Mostly useful
      with xargs(1). See its documentation.

Notes:

The output table header will be the one taken from 'table',
and 'table', if present, must appear first in the list
of non-option arguments. This is useful in constructs like:

find path/ -name '*.rdb' | xargs -n x union --xargs table1

where 'x' is the max. number of 'table' parameters passed
to a single instance of 'union' by xargs(1).
Make sure that 'table1' is specified in the way it
is printed by find(1), i.e: 'path/.../file.rdb'

Warning: if the files being listed with find(1) are known
to contain spaces or other special characters in their names,
then 'find -print0' should be used instead. See find(1) for
more information.

The tables listed on the command line must all have the same
structure, with the same number of columns, i.e. they must be
union-compatible.

$Id$
