FLOAD

Translation references to convert Teradata FLOAD files to Python

Teradata FastLoad is a command‑driven utility for quickly loading large amounts of data in an empty table on a Teradata Database.

In order to simulate the FastLoad functionality for Teradata in Snowflake, FastLoad files and commands are transformed to Python code, similar to the transformations performed for BTEQ and MultiLoad scripts. The generated code uses the Snowflake Python project called snowconvert.helpers which contains the required functions to simulate the FastLoad statements in Snowflake.

FastLoad Commands Translation

Most of the FastLoad commands are considered not relevant in Snowflake, these commands are commented out. Below is the summary list of FastLoad commands and their transformation status into Snowflake:

Teradata FastLoad Command

Transformation Status

Note

AXSMOD

Commented

Transformed

​The node is commented out since the transformation occurs in the related INSERT statement instead.

CLEAR

Commented

DATEFORM

Commented

Transformed

Transformed

​Commented out since is not necessary for the transformation of the BEGIN LOADING.

ERRLIMIT

Commented

HELP

Commented

HELP TABLE

Commented

Transformed

Transformed as part of the BEGIN LOADING.

LOGDATA

Commented

LOGMECH

Commented

LOGOFF

Commented

LOGON

Commented

NOTIFY

Commented

OS

Commented

QUIT

Commented

RECORD

Commented

RUN

Commented

SESSIONS

Commented

Transformed

SET SESSION CHARSET

Commented

SHOW

Commented

SHOW VERSIONS

Commented

SLEEP

Commented

TENACITY

Commented

Default Transformation

The default behavior of the ConversionTool for these statements is to comment them out. For example:

Teradata (FastLoad)

SESSIONS 4;
ERRLIMIT 25;

Snowflake (Python)

   #** MSC-WARNING - MSCEWI1002 - REMOVED NEXT STATEMENT, NOT APPLICABLE IN SNOWFLAKE. SESSIONS 4 **
    
   #** MSC-WARNING - MSCEWI1002 - REMOVED NEXT STATEMENT, NOT APPLICABLE IN SNOWFLAKE. ERRLIMIT 25 **

Nonetheless, there are some exceptions that must be converted to specific Python statements in order to work as intended in Snowflake.

The transformation for the command BEGIN LOADING is a multi-part transformation that requires the DEFINE, INSERT and (optionally) SET RECORD commands to simulate its behavior correctly.

This transformation is fully explained in this section.

SET RECORD

As stated above, this command is not required for the transformation of the BEGIN LOADING. If not found, the default delimiter will be set to ',' (comma). Else, the defined delimiter will be used.

Teradata (FastLoad)

BEGIN LOADING FastTable ERRORFILES Error1,Error2
   CHECKPOINT 10000;

Snowflake (Python)

exec(f"""COPY INTO FastTable FROM {inputDataPlaceholder} ON_ERROR = CONTINUE""")
exec("""CREATE TABLE CTE_FastTable AS SELECT DISTINCT * FROM FastTable""")
exec("""DROP TABLE FastTable""")
exec("""ALTER TABLE CTE_FastTable RENAME TO FastTable""")

In the example above, FastTable is the name of the table associated to the BEGIN LOADING command. Note the use of the python variableinputDataPlaceholder, that must be defined by the user in a previous step. The value represents the Snowflake stage that could be internal or external as shown in the following table or as explained here.

Stage

Input Data Place Holder

Internal stage

@my_int_stage

External stage

@my_int_stage/path/file.csv

Amazon S3 bucket

s3://mybucket/data/files

Google Cloud Storage

gcs://mybucket/data/files

Microsoft Azure

azure://myaccount.blob.core.windows.net/mycontainer/data/files

Embedded SQL

FastLoad scripts support Teradata statements inside the same file. The majority of these statements are converted just as if they were inside a BTEQ file, with some exceptions.

Dropping an error table is commented out if inside a FastLoad file.

Teradata (FastLoad)

DROP TABLE Error1;
DROP TABLE Error2;

Snowflake (Python)

#** MSC-WARNING - MSCEWI2022 - COMMENTED OUT CODE RELATED WITH DROPPING WORK OR ERROR TABLE.
#DROP TABLE Error1 **
    
#** MSC-WARNING - MSCEWI2022 - COMMENTED OUT CODE RELATED WITH DROPPING WORK OR ERROR TABLE.
#DROP TABLE Error2 **

Large Example

Given the transformations shown above for a variety of commands, consider the following example.

Teradata (FastLoad)

SESSIONS 4;
ERRLIMIT 25;
DROP TABLE FastTable;
DROP TABLE Error1;
DROP TABLE Error2;
CREATE TABLE FastTable, NO FALLBACK
   ( ID INTEGER, UFACTOR INTEGER, MISC CHAR(42))
   PRIMARY INDEX(ID);
DEFINE ID (INTEGER), UFACTOR (INTEGER), MISC (CHAR(42))
   FILE=FileName;
SHOW;
BEGIN LOADING FastTable ERRORFILES Error1,Error2
   CHECKPOINT 10000;
INSERT INTO FastTable (ID, UFACTOR, MISC) VALUES
   (:ID, :MISC);
END LOADING;

Snowflake (Python)

#*** Generated code is based on the SnowConvert Python Helpers version 2.0.* ***
 
import os

import sys

import snowconvert.helpers

from snowconvert.helpers import Export
from snowconvert.helpers import exec
con = None

def main():
   snowconvert.helpers.configure_log()
   con = snowconvert.helpers.log_on()
   #** MSC-WARNING - MSCEWI1002 - REMOVED NEXT STATEMENT, NOT APPLICABLE IN SNOWFLAKE. SESSIONS 4 **
    
   #** MSC-WARNING - MSCEWI1002 - REMOVED NEXT STATEMENT, NOT APPLICABLE IN SNOWFLAKE. ERRLIMIT 25 **
    
   exec("""DROP TABLE PUBLIC.FastTable""")
   #** MSC-WARNING - MSCEWI2022 - COMMENTED OUT CODE RELATED WITH DROPPING WORK OR ERROR TABLE.
   #DROP TABLE Error1 **
    
   #** MSC-WARNING - MSCEWI2022 - COMMENTED OUT CODE RELATED WITH DROPPING WORK OR ERROR TABLE.
   #DROP TABLE Error2 **
    
   exec("""CREATE TABLE PUBLIC.FastTable
(
ID INTEGER,
UFACTOR INTEGER,
MISC CHAR(42))""")
   #** MSC-WARNING - MSCEWI1002 - REMOVED NEXT STATEMENT, NOT APPLICABLE IN SNOWFLAKE. DEFINE ID (INTEGER), UFACTOR (INTEGER), MISC (CHAR(42))
   #   FILE=FileName **
    
   #** MSC-WARNING - MSCEWI1002 - REMOVED NEXT STATEMENT, NOT APPLICABLE IN SNOWFLAKE. SHOW **
    
   exec(f"""COPY INTO FastTable FROM {inputDataPlaceholder} ON_ERROR = CONTINUE""")
   exec("""CREATE TABLE CTE_FastTable AS SELECT DISTINCT * FROM FastTable""")
   exec("""DROP TABLE FastTable""")
   exec("""ALTER TABLE CTE_FastTable RENAME TO FastTable""")
   #** MSC-WARNING - MSCEWI1002 - REMOVED NEXT STATEMENT, NOT APPLICABLE IN SNOWFLAKE. END LOADING **
    
   snowconvert.helpers.quit_application()

if __name__ == "__main__":
   main()

If you have any additional questions regarding this documentation, you can email us at snowconvert-support@snowflake.com.

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