Re: How to compress a table?

From: Andrew Finkenstadt <andy_at_vistachrome.com>
Date: Sun, 25 Apr 1993 19:10:27 GMT
Message-ID: <C61zxF.HG5_at_vistachrome.com>

c343b02_at_hawk.depaul.edu (history!) writes:
>How do you compress a table in Oracle V.6.0A for DOS on one PC
>then uncompress on another PC running Oracle? What is the
>percentage of compression?
>Thanks in advance.

Compression, with respect to Oracle IMPORT/EXPORT does NOT save space, but does put all data into ONE extent per segment. So, in brief:

% exp help=y
Export: Version 6.0.36.4.1 - Production on Sun Apr 25 15:09:30 1993 Copyright (c) Oracle Corporation 1979, 1992. All rights reserved.

You can let Export prompt you for parameters by entering the EXP command followed by your username/password:

     Example: EXP SCOTT/TIGER

Or, you can control how Export runs by entering the EXP command followed by various arguments. To specify parameters, you use keywords:

     Format:  EXP KEYWORD=value or KEYWORD=(value1,value2,...,valueN)
     Example: EXP SCOTT/TIGER GRANTS=Y TABLES=(EMP,DEPT,MGR)

Keyword  Description (Default)        Keyword      Description (Default)
--------------------------------------------------------------------------
USERID   username/password            FULL         export entire file (N)
BUFFER   size of data buffer          OWNER        list of owner usernames
FILE     output file (EXPDAT.DMP)     TABLES       list of table names
COMPRESS import into one extent (Y)   RECORDLENGTH length of IO record
GRANTS   export grants (N)            INCTYPE      incremental export type
INDEXES  export indexes (Y)           RECORD       track incr. export (Y)
ROWS     export data rows (Y)         PARFILE      parameter filename

CONSTRAINTS export table constraints (N)

Turn on COMPRESS and write it to a file on MS-DOS. Now transfer the file from one machine to the other - if using FTP be SURE to turn on BINARY mode, then use IMP to import the resulting exported file.

-Andy

-- 
Andrew Finkenstadt, Vista-Chrome, Inc., Homes & Land Publishing Corporation
GEnie Unix RoundTable Manager, andy_at_vistachrome.com, andy_at_genie.geis.com.
"[The author] neither accidentally nor intentionally omits or includes 
anything that could support a preconceived thesis." - C&EN 21-DEC-92 p.72

Received on Sun Apr 25 1993 - 21:10:27 CEST