Introduction to teradata utilities : BTEQ

BTEQ is a Teradata native query tool for DBA and programmers. BTEQ (Basic
TEradata Query) is a command-driven utility used to 1) access and manipulate
data, and 2) format reports for both print and screen output.




DEFINITION

BTEQ, short for Basic TEradata Query,
is a general-purpose command-driven utility used to access and manipulate data
on the Teradata Database, and format reports for both print and screen output. [1]



OVERVIEW

As part of the Teradata Tools and Utilities (TTU), BTEQ is a
Teradata native query tool for DBA and programmers — a real Teradata workhorse,
just like SQLPlus for the Oracle Database. It enables users on a workstation to
easily access one or more Teradata Database systems for ad hoc queries, report
generation, data movement (suitable for small volumes) and database
administration.

All database requests in BTEQ are expressed in Teradata
Structured Query Language (Teradata SQL). You can use Teradata SQL statements
in BTEQ to:

    * Define
      data — create and modify data structures;
    * Select
      data — query a database;
    * Manipulate
      data — insert, delete, and update data;
    * Control
      data — define databases and users, establish access rights, and secure
      data;
    * Create
      Teradata SQL macros — store and execute sequences of Teradata SQL
      statements as a single operation.


BTEQ supports Teradata-specific SQL functions for doing
complex analytical querying and data mining, such as:

    * RANK -
      (Rankings);
    * QUANTILE
      - (Quantiles);
    * CSUM -
      (Cumulation);
    * MAVG -
      (Moving Averages);
    * MSUM -
      (Moving Sums);
    * MDIFF
      - (Moving Differences);
    * MLINREG
      - (Moving Linear Regression);
    * ROLLUP
      - (One Dimension of Group);
    * CUBE -
      (All Dimensions of Group);
    * GROUPING
      SETS - (Restrict Group);
    * GROUPING
      - (Distinguish NULL rows).


Noticeably, BTEQ supports the conditional logic (i.e.,
"IF..THEN..."). It is useful for batch mode export / import
processing.



OPERATING FEATURES

This section is based on Teradata documentation for the
current release.[1]



BTEQ Sessions

In a BTEQ session, you can access a Teradata Database easily
and do the following:

    * enter
      Teradata SQL statements to view, add, modify, and delete data;
    * enter
      BTEQ commands;
    * enter
      operating system commands;
    * create
      and use Teradata stored procedures.






Operating Modes

BTEQ operates in two modes: interactive mode and batch mode.
In interactive mode, you start a BTEQ session by entering BTEQ at
the system prompt on your terminal or workstation, and submit commands to the
database as needed. In batch mode, you prepare BTEQ scripts or macros, and then
submit them to BTEQ from a scheduler for processing. A BTEQ script is a set of
SQL statements and BTEQ commands saved in a file with the extension
".bteq"; however, it does not matter what file extension is used. The
BTEQ script can be run using the following command (in UNIX or Windows):

bteq < infle > outfile

Here infile is the BTEQ script, and outfile
is the output or log file.



BTEQ COMMANDS

This section is based on Teradata documentation[1],
and for the detailed usage, please refer to Reference 1.



BTEQ Command Summary

BTEQ commands can be categorized into four functional
groups, as described below:

    * Session
      control — Session control commands begin and end BTEQ sessions, and control
      session characteristics;
    * File
      control — specify input and output formats and identify information
      sources and destinations;
    * Sequence
      control — control the sequence in which other BTEQ commands and Teradata
      SQL statements will be executed within scripts and macros;
    * Format
      control — control the format of screen and printer output.

[edit]

1. Commands for Session Control

COMMAND NAME	FUNCTION
ABORT	abort any active requests and transactions without exiting BTEQ.
COMPILE	create or replace a Teradata stored procedure.
DECIMALDIGITS	override the precision specified by a CLI System Parameter Block (SPB) max_decimal_returned entry, or if that entry does not exist, to indicate what the precision should be for decimal values associated with subsequently issued SQL requests for non-fieldmode responses.
DEFAULTS	Resets BTEQ command options to the values that were set when BTEQ was first invoked.
EXIT	end the current sessions and exit BTEQ.
HALT EXECUTION	abort any active requests and transactions and exit BTEQ; also called "HX".
LOGOFF	end the current sessions without exiting BTEQ.
LOGON	start a BTEQ session.
LOGONPROMPT	bypass the warnings related to conventional LOGON command use.
QUIT	end the current sessions and exit BTEQ.
SESSION CHARSET	specify the name of a character set for the current session.
SESSION RESPBUFLEN	override the buffer length specified in resp_buf_len.
SESSION SQLFLAG	specify the disposition of warnings issued in response to violations of ANSI-compliant syntax.
SESSION TRANSACTION	specify whether transaction boundaries are determined by Teradata SQL semantics or ANSI semantics.
SESSION TWORESPBUFS	specify whether CLI double-buffering is used.
SESSIONS	specify the number of sessions to use with the next LOGON command.
SHOW CONTROLS	display the current configuration of the BTEQ control command options.
SHOW VERSIONS	display the BTEQ version number, module revision numbers, and linking date.
TDP	specify the Teradata server for subsequent logons during the current session.

[edit]

2. Commands for File Control

COMMAND NAME	FUNCTION
=	Repeats the previous Teradata SQL request a specified number of times.
AUTOKEYRETRIEVE	enables users to specify whether the values of any fields associated with Identity Data are returned in response to a SQL Insert operation.
CMS	executes a VM CMS command from within the BTEQ environment.
ERROROUT	Routes the standard error stream and the standard output stream to two files or devices for channel-attached systems, or to one file or device for network-attached client systems.
EXPORT	Specifies the name and format of an export file that BTEQ will use to store database information returned by a subsequent SQL SELECT statement.
EXPORTEJECT	Enables suppression of the additional Page Advance ASA Carriage Control Character at the top of the EXPORT file in REPORT mode for MVS/VM BTEQ.
HALT EXECUTION	aborts any active requests and transactions and exit BTEQ; also called "HX".
FORMAT	Enables all of the page-oriented formatting commands, or disables them and centers the response from SQL SELECT statements, using the value of the WIDTH command option to determine the space available.
IMPORT	Opens a channel- or network-attached system file, of the specified format, to provide data for USING modifiers of subsequent SQL statements.
INDICDATA	Specifies the mode of information returned from the Teradata Database in response to SQL SELECT statements.
INDICDATA and / or LARGEDATAMODE	specify the response mode, either Field mode, Indicator mode, Record mode, or Multipart Indicator Mode, for data selected from the Teradata Database.
LARGEDATAMODE	Enables use of Teradata Database’s Multipart Indicator response mode for inline mode retrieval of Large Object (LOB) data. BTEQ limits the record size for exported files to approximately 64K (65473 for workstation builds and 64260 for mainframe builds). If more than 64K is required, SET LARGEDATAMODE allows hex-dump style output (similar to RecordMode directed to standard output).
OS	executes an MS-DOS, PC-DOS, or UNIX command from within the BTEQ environment.
QUIET	Limits BTEQ output to errors and request processing statistics. BTEQ displays the results in a format that is suitable for performance testing.
RECORDMODE	Returns data from SQL SELECT statements in client-oriented data representations rather than character format.
REPEAT	submits the next request a specified number of times.
RUN	executes Teradata SQL requests and BTEQ commands from a specified run file.
TSO	executes an MVS TSO command from within the BTEQ environment.

[edit]

3. Commands for Sequence Control

Use the following commands to control the sequence in which
BTEQ executes commands:

• ABORT
• ERRORLEVEL
  
• EXIT
• GOTO
• HANG
• IF...
  THEN...
• LABEL
• MAXERROR
  
• QUIT
• REMARK
  
• REPEAT
  
• =

For the commands not listed below, refer to the tables
above.

COMMAND NAME	FUNCTION
ERRORLEVEL	Assigns severity levels to errors.
GOTO	Skips over all intervening BTEQ commands and SQL statements until a specified label is encountered, then resumes processing in sequence.
HANG	Pauses BTEQ processing for a specified period of time.
IF... THEN...	Tests the validity of the condition stated in the IF clause.
LABEL	Identifies the point at which BTEQ resumes processing, as specified in a previous GOTO command.
MAXERROR	Designates a maximum error severity level beyond which BTEQ terminates job processing.

[edit]

4. Format Control Commands

Use the following BTEQ commands to specify the way BTEQ
presents information for screenoriented and printer/printer-file oriented
output:

• DEFAULTS
  
• ECHOREQ
  
• EXPORT
  
• FOLDLINE
  
• FOOTING
  
• FORMAT
  
• HEADING
  
• IMPORT
  
• INDICDATA
  
• NULL
• OMIT
• PAGEBREAK
  
• PAGELENGTH
  
• QUIET
• RECORDMODE
  
• RETCANCEL
  
• RETLIMIT
  
• RETRY
• RTITLE
  
• SEPARATOR
  
• SHOW
  CONTROLS
• SIDETITLES
  
• SKIPDOUBLE
  
• SKIPLINE
  
• SUPPRESS
  
• TITLEDASHES
  
• UNDERLINE
  
• WIDTH

For the commands not listed below, refer to the tables
above.

COMMAND NAME	FUNCTION
ECHOREQ	Enables the echo required function that returns a copy of each Teradata SQL request and BTEQ command to the standard output stream.
FOLDLINE	Splits (fold) each line of a report into two or more lines.
FOOTING	Specifies a footer to appear at the bottom of every page of a report.
HEADING	Specifies a header to appear at the top of every page of a report.
NULL	Specifies a character or character string to represent null field values returned from the Teradata Database.
OMIT	Excludes specified columns returned from SQL SELECT statements.
PAGEBREAK	Ejects a page whenever the value for one or more specified columns changes.
PAGELENGTH	specify the page length of printed reports, in lines per page.
RETCANCEL	cancel a request when the value specified by the RETLIMIT command ROWS option is exceeded.
RETLIMIT	Specifies the maximum number of rows and/or columns displayed or written in response to a Teradata SQL request.
RETRY	resubmit requests that fail under certain error conditions.
RTITLE	Specifies a header to appear at the top of every page of a report.
SEPARATOR	Specifies a character string or width (in blank characters) to separate columns of a report.
SIDETITLES	Position summary titles to the left of the summary lines in a report.
SKIPDOUBLE	insert two blank lines in a report whenever the value of a specified column changes.
SKIPLINE	Inserts a blank line in a report whenever the value of a specified column changes.
SUPPRESS	Replaces all consecutively repeated values with all-blank character strings.
TITLEDASHES	Display a row of dash characters before each report line summarized by a WITH clause.
UNDERLINE	Displays a row of dash characters whenever the value of a specified column changes.
WIDTH	Specifies the width of screen displays and printed reports, in characters per line.