EVL – ETL Tool


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Table of Contents

Readqvd

(since EVL 2.3)

Write to standard output or <f_out> the content of the <file.qvd>. It parses fields as they are specified in EVD file, unless ‘--match-fields’ is specified.

Premium and Enterprise Edition

If there are less fields in the EVD file than in QVD, only such fields are returned. This functinality is not available for Trial and Standard Edition.

Readqvd

is to be used in EVS job structure definition file. <f_out> is either output file or flow name.

evl readqvd

is intended for standalone usage, i.e. to be invoked from command line and reading records from standard input.

EVD and EVS are EVL definition files, for details see evl-evd(5) and evl-evs(5).

Synopsis

Readqvd
  <file.qvd> <f_out> (<evd>|-d <inline_evd>)
  [-y|--text-output | -a|--text-output-dos-eol | -b|--text-output-mac-eol]
  [-m|--match-fields]
  [-n|--null-as-string[=<string>]]
  [--filter=<condition>]
  [--first-record=<n>]
  [--guess-uniform-symbol-size]
  [--low-memory]

evl readqvd
  <file.qvd> (<evd>|-d <inline_evd>)
  [-y|--text-output | -a|--text-output-dos-eol | -b|--text-output-mac-eol]
  [-m|--match-fields]
  [-n|--null-as-string[=<string>]]
  [--filter=<condition>]
  [--first-record=<n>]
  [--guess-uniform-symbol-size]
  [--low-memory]
  [-v|--verbose]

evl readqvd
  ( --help | --usage | --version )

Options

-d, --data-definition=<inline_evd>

either this option or the file <evd> must be presented. Example: ‘-d 'id int, name string, started timestamp'

-m, --match-fields

match fields between EVD and QVD, otherwise they are taken one by one from input QVD file. If there are less fields in the EVD file than in QVD, only such fields are returned. This functinality is not available for Trial and Standard Edition.

-n, --null-as-string[=<string>]

read <string> as a NULL value, without <string> specified it reads an empty string as NULL

--filter=<condition>

read only records with given <condition>. (Since EVL 2.6.)

--first-record=<n>

start to read from the record number <n>. (Since EVL 2.6.)

--guess-uniform-symbol-size

might speed up indexing of dictionary, but it could not work in all cases. Use only to in special cases when need really good performance. (Since EVL 2.6.)

--low-memory

do not read dictionary into memory. This could save memory consumption, but slows down reading the source file. (Since EVL 2.6.)

-y, --text-output

write the output as text, not binary

--text-output-dos-eol

produce the output as text with CRLF as end of line

--text-output-mac-eol

produce the output as text with CR as end of line

Standard options:

--help

print this help and exit

--usage

print short usage information and exit

-v, --verbose

print to stderr info/debug messages of the component

--version

print version and exit