12-31-2012
Hi Pamu,
Thanks for your response.
Just i wanted to know, whether zcat is recommended for large files(more than 40GB).
I wanted to implement compressed loading in oracle while using external table load strategy.
For that i need to have zcat in bin directory. just i suspect how zcat will behave for huge files.
And also i want to understand the internal implementation of zcat.
i believe zcat should un-compress the original file intermediately somewhere and read.
although we don't see any impact in small files, i want to make sure the impact for the huge files.
thanks
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Commands Reference, Volume 6, v - z
zcat_Command
Purpose
Expands a compressed file to standard output.
Syntax
zcat [ -n ] [ -V ] [ File ... ]
Description
The zcat command allows the user to expand and view a com-
pressed file
without uncompressing that file. The zcat command does not re-
name the
expanded file or remove the .Z extension. The zcat command
writes the
expanded output to standard output.
Flags
-n Omits the compressed file header from the compressed
file.
-V Writes the current version and compile options to stan-
dard error.
Parameters
File ... Specifies the compressed files to expand.
Return Values
If the zcat command exits with a status of 1 if any of the
following
events occur:
* The input file was not produced by the compress command.
* An input file cannot be read or an output file cannot be
written.
If no error occurs, the exit status is 0.
Exit Status
0 Successful completion.
>0 An error occurred.
Examples
To view the foo.Z file without uncompressing it, enter:
zcat foo.Z
The uncompressed contents of the foo.Z file are written to
standard
output. The file is not renamed.
Related Information
The compress command, pack command, uncompress command,
unpack command.
Commands in Operating system and device management.
________________________________________________________________________________
Commands Reference, Volume 6, v - z
zcat_Command
Purpose
Expands a compressed file to standard output.
Syntax
zcat [ -n ] [ -V ] [ File ... ]
Description
The zcat command allows the user to expand and view a com-
pressed file
without uncompressing that file. The zcat command does not re-
name the
expanded file or remove the .Z extension. The zcat command
writes the
expanded output to standard output.
Flags
-n Omits the compressed file header from the compressed
file.
-V Writes the current version and compile options to stan-
dard error.
Parameters
File ... Specifies the compressed files to expand.
Return Values
If the zcat command exits with a status of 1 if any of the
following
events occur:
* The input file was not produced by the compress command.
* An input file cannot be read or an output file cannot be
written.
If no error occurs, the exit status is 0.
Exit Status
0 Successful completion.
>0 An error occurred.
Examples
To view the foo.Z file without uncompressing it, enter:
zcat foo.Z
The uncompressed contents of the foo.Z file are written to
standard
output. The file is not renamed.
Related Information
The compress command, pack command, uncompress command,
unpack command.
Commands in Operating system and device management.