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# union.txt: help text
# Copyright (c) 2001,2002,2003 Carlo Strozzi
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# $Id: union.txt,v 1.3 2003/09/23 10:11:36 carlo Exp $

                      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.

    --first-table (-f) 'table'
      Read the table header from 'table'. Mostly useful when
      'union' is run from xargs(1). See below.

Notes:

The output table header will be taken from 'table' and the latter,
if present, is expected to be the first non-option argument. This
is useful in constructs like:

find path/ -name '*.table' | xargs [-n num] union --first-table table1

where 'num' 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.table'

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.

