SQL * Loader
SQL*loader is one of the Oracle tool which will be used to transfer the data from Flat-File to oracle Database table.
We can find the fallowing files in SQL*loader
1. Flat or Data File
2. Control File
3. Bad File
4. Discard File
5. Log File
1. Flat or Data File
2. Control File
3. Bad File
4. Discard File
5. Log File
Flat Or Data File: This file contains the records in a special format; these records will be fetching for other legacy. The extension of these files might be .dat, .txt, or .csv (comma separated view).
Control File: This is SQL loader execution file, which will be used to transfer the date from file to table. In side of these control file, we will mention the Data file path, table name, column mapping. The extension of control file is .ctl
Control File Creation:
Load data
INFILE ‘Data File Path’
INSERT INTO ‘Table Name’
FIELD TERMINATED BY ‘,’
WHERE deptno = 10
TRAILING NULL COLS(column1 , empno
column2, ename
column3, deptno)
INFILE ‘Data File Path’
INSERT INTO ‘Table Name’
FIELD TERMINATED BY ‘,’
WHERE deptno = 10
TRAILING NULL COLS(column1 , empno
column2, ename
column3, deptno)
Once we develop the control file we will execute this by using fallowing command
C:\> sqlldr user/passward @ Database Control = name of control file (with extension .ctl)This command will start the control file execution, and it will try to read the data and inserting into table. After completion of this execution, automatically three files will gets created
Bad file
Discard file
Log file
Bad File: Bad file contain the records, which are rejected by the SQL*loader. SQL*loader will reject the records, when ever the Flat file format is not correct or if any internal error occurs it will rejected. The extension of bad file is .bad
Discard File: Discard file contains the records which are rejected by the control file, control file reject the records, if record is not satisfying the conditions, which we have mentioned inside of control files the extension of discard file is .dis
Logfile: It contains the complete info of the process, like no of records successfully loaded in to the table
No of records successfully loaded in to the bad file & discard file.
And where the bad, discard file gets created and time taken to complete the process.
Taking the complete log.
LOAD DATA statement is required at the beginning of the control file.
INFILE: INFILE keyword is used to specify location of the datafile or datafiles.
INFILE * specifies that the data is found in the control file and not in an external file. INFILE '$FILE', can be used to send the filepath and filename as a parameter when registered as a concurrent program.
INFILE '/home/vision/kap/import2.csv' specifies the filepath and the filename.
INTO TABLE is required to identify the table to be loaded into. In the above example INTO TABLE "APPS"."BUDGET", APPS refers to the Schema and BUDGET is the Table name.
FIELDS TERMINATED BY specifies how the data fields are terminated in the datafile.(If the file is Comma delimited or Pipe delimited etc)
OPTIONALLY ENCLOSED BY '"' specifies that data fields may also be enclosed by quotation marks.
TRAILING NULLCOLS clause tells SQL*Loader to treat any relatively positioned columns that are not present in the record as null columns.
OPTION statement precedes the LOAD DATA statement. The OPTIONS parameter allows you to specify runtime arguments in the control file, rather than on the command line. The following arguments can be specified using the OPTIONS parameter.
SKIP = n -- Number of logical records to skip (Default 0)
LOAD = n -- Number of logical records to load (Default all)
ERRORS = n -- Number of errors to allow (Default 50)
ROWS = n -- Number of rows in conventional path bind array or between direct path data saves (Default: Conventional Path 64, Direct path all)
BINDSIZE = n -- Size of conventional path bind array in bytes (System-dependent default)
SILENT = {FEEDBACK | ERRORS | DISCARDS | ALL} -- Suppress messages during run
(header, feedback, errors, discards, partitions, all)
DIRECT = {TRUE | FALSE} --Use direct path (Default FALSE)
PARALLEL = {TRUE | FALSE} -- Perform parallel load (Default FALSE)
SQL* Loader Modes:
TYPE OF LOADING:
INSERT -- If the table you are loading is empty, INSERT can be used.
APPEND -- If data already exists in the table, SQL*Loader appends the new rows to it. If data doesn't already exist, the new rows are simply loaded.
REPLACE -- All rows in the table are deleted and the new data is loaded
TRUNCATE -- SQL*Loader uses the SQL TRUNCATE command.
C:\> sqlldr userid/passward@Database control=text1.ctl path=direct
SQL* Loader Paths: We can execution SQL* loader in two paths or nodes
Direct
Conventional
By default SQL*loader will be running in conventional mode, if we want to run in direct mode will use the fallowing syntax
C:\> sqlldr userid/passward@Database control=text1.ctl path=direct
Direct mode will disable the table and column constrains and it will insert the data.
Conventional path will check every constrains, if it is satisfied it will insert the record
Conventional path is just like ‘insert statement’
SQL Commands Limitations:to_date, to_char, upper, lower, Initcap, string, decode, nvl
when clause
sequence_name.next_value, Ref-Cursor
sysdate, ltrim, rtrim, constant
Structure of a Control file:
Sample CTL file for loading a Variable record data file:
OPTIONS (SKIP = 1) --The first row in the data file is skipped without loading
LOAD DATA
INFILE '$FILE' -- Specify the data file path and name
APPEND -- type of loading (INSERT, APPEND, REPLACE, TRUNCATE
INTO TABLE "APPS"."BUDGET" -- the table to be loaded into
FIELDS TERMINATED BY '|' -- Specify the delimiter if variable format datafile
OPTIONALLY ENCLOSED BY '"' --the values of the data fields may be enclosed in "
TRAILING NULLCOLS -- columns that are not present in the record treated as null
(ITEM_NUMBER "TRIM(:ITEM_NUMBER)", -- Can use all SQL functions on columns
QTY DECIMAL EXTERNAL,
REVENUE DECIMAL EXTERNAL,
EXT_COST DECIMAL EXTERNAL TERMINATED BY WHITESPACE "(TRIM(:EXT_COST))" ,
MONTH "to_char(LAST_DAY(ADD_MONTHS(SYSDATE,-1)),'DD-MON-YY')" ,
DIVISION_CODE CONSTANT "AUD" -- Can specify constant value instead of
Getting value from datafile
)
Skip columns:
You can skip columns using the 'FILLER' option.
Load Data
--
--
--
TRAILING NULLCOLS
(
name Filler,
Empno ,
sal
)
--
--
--
TRAILING NULLCOLS
(
name Filler,
Empno ,
sal
)
here the column name will be skipped.
Steps to Run the SQL* LOADER from UNIX:
At the prompt, invoke SQL*Loader as follows:
sqlldr USERID=scott/tiger CONTROL= LOG=
name>
SQL*Loader loads the tables, creates the log file, and returns you to the system prompt. You can check the log file to see the results of running the case study.
Register as concurrent Program:
Place the Control file in $CUSTOM_TOP/bin.
Define the Executable. Give the Execution Method as SQL*LOADER.
Define the Program. Add the Parameter for FILENAME.
SQL Loader
What is SQL*Loader and what is it used for?SQL*Loader is a bulk loader utility used for moving data from external files into the Oracle database. Its syntax is similar to that of the DB2 load utility, but comes with more options. SQL*Loader supports various load formats, selective loading, and multi-table loads.
How does one use the SQL*Loader utility?
One can load data into an Oracle database by using the sqlldr (sqlload on some platforms) utility. Invoke the utility without arguments to get a list of available parameters. Look at the following example: sqlldr username@server/password control=loader.ctl
This sample control file (loader.ctl) will load an external data file containing delimited data: load data
infile 'c:\data\mydata.csv'
into table emp
fields terminated by "," optionally enclosed by '"'
( empno, empname, sal, deptno )
The mydata.csv file may look like this: 10001,"Scott Tiger", 1000, 40
10002,"Frank Naude", 500, 20
Another Sample control file with in-line data formatted as fix length records. The trick is to specify "*" as the name of the data file, and use BEGINDATA to start the data section in the control file: load data
infile *
replace
into table departments
( dept position (02:05) char(4),
deptname position (08:27) char(20)
)
begindata
COSC COMPUTER SCIENCE
ENGL ENGLISH LITERATURE
MATH MATHEMATICS
POLY POLITICAL SCIENCE
How does one load MS-Excel data into Oracle?Open the MS-Excel spreadsheet and save it as a CSV (Comma Separated Values) file. This file can now be copied to the Oracle machine and loaded using the SQL*Loader utility.
Possible problems and workarounds:
The spreadsheet may contain cells with newline characters (ALT+ENTER). SQL*Loader expects the entire record to be on a single line. Run the following macro to remove newline characters (Tools -> Macro -> Visual Basic Editor): ' Removing tabs and carriage returns from worksheet cells
Sub CleanUp()
Dim TheCell As Range
On Error Resume Next
For Each TheCell In ActiveSheet.UsedRange
With TheCell
If .HasFormula = False Then
.Value = Application.WorksheetFunction.Clean(.Value)
End If
End With
Next TheCell
End Sub
Tools:
If you need a utility to load Excel data into Oracle, download quickload from sourceforge athttp://sourceforge.net/projects/quickload
Is there a SQL*Unloader to download data to a flat file?Oracle does not supply any data unload utilities. Here are some workarounds:
Using SQL*Plus
You can use SQL*Plus to select and format your data and then spool it to a file. This example spools out a CSV (common separated values) file that can be imported into MS-Excel: set echo off newpage 0 space 0 pagesize 0 feed off head off trimspool on
spool oradata.txt
select col1 ',' col2 ',' col3
from tab1
where col2 = 'XYZ';
spool off
You can also use the "set colsep ," command if you don't want to put the commas in by hand. This saves a lot of typing: set colsep ,
set echo off newpage 0 space 0 pagesize 0 feed off head off trimspool on
spool oradata.txt
select col1, col2, col3
from tab1
where col2 = 'XYZ';
spool off
Using PL/SQL
PL/SQL's UTL_FILE package can also be used to unload data. Example: declare
fp utl_file.file_type;
begin
fp := utl_file.fopen('c:\oradata','tab1.txt','w');
utl_file.putf(fp, '%s, %sn', 'TextField', 55);
utl_file.fclose(fp);
end;
/
Third-party programs
You might also want to investigate third party tools to help you unload data from Oracle. Here are some examples:
WisdomForce FastReader - http://www.wisdomforce.com
IxUnload from ixionsoftware.com - http://www.ixionsoftware.com/products/
FAst extraCT (FACT) for Oracle from CoSort - http://www.cosort.com/products/FACT
Unicenter (also ManageIT or Platinum) Fast Unload for Oracle from CA
Keeptool's Hora unload/load facility (part v5 to v6 upgrade) can export to formats cuch as as Microsoft Excel, DBF, XML, and text - http://www.keeptool.com/en/keeptool_hora.php
TOAD from Quest
SQLWays from Ispirer Systems
PL/SQL Developer from allroundautomation
Can one load variable and fix length data records?
Loading delimited (variable length) data
In the first example we will show how delimited (variable length) data can be loaded into Oracle: LOAD DATA
INFILE *
INTO TABLE load_delimited_data
FIELDS TERMINATED BY "," OPTIONALLY ENCLOSED BY '"'
TRAILING NULLCOLS
( data1,
data2
)
BEGINDATA
11111,AAAAAAAAAA
22222,"A,B,C,D,"
NOTE: The default data type in SQL*Loader is CHAR(255). To load character fields longer than 255 characters, code the type and length in your control file. By doing this, Oracle will allocate a big enough buffer to hold the entire column, thus eliminating potential "Field in data file exceeds maximum length" errors. Example: ...
resume char(4000),
...
Loading positional (fixed length) data
If you need to load positional data (fixed length), look at the following control file example: LOAD DATA
INFILE *
INTO TABLE load_positional_data
( data1 POSITION(1:5),
data2 POSITION(6:15)
)
BEGINDATA
11111AAAAAAAAAA
22222BBBBBBBBBB
For example, position(01:05) will give the 1st to the 5th character (11111 and 22222).
Can one skip header records while loading?
One can skip unwanted header records or continue an interrupted load (for example if you run out of space) by specifying the "SKIP=n" keyword. "n" specifies the number of logical rows to skip. Look at these examples: OPTIONS (SKIP=5)
LOAD DATA
INFILE *
INTO TABLE load_positional_data
( data1 POSITION(1:5),
data2 POSITION(6:15)
)
BEGINDATA
11111AAAAAAAAAA
22222BBBBBBBBBB
...
sqlldr userid=ora_id/ora_passwd control=control_file_name.ctl skip=4
If you are continuing a multiple table direct path load, you may need to use the CONTINUE_LOAD clause instead of the SKIP parameter. CONTINUE_LOAD allows you to specify a different number of rows to skip for each of the tables you are loading.
Can one modify data as the database gets loaded?Data can be modified as it loads into the Oracle Database. One can also populate columns with static or derived values. However, this only applies for the conventional load path (and not for direct path loads). Here are some examples: LOAD DATA
INFILE *
INTO TABLE modified_data
( rec_no "my_db_sequence.nextval",
region CONSTANT '31',
time_loaded "to_char(SYSDATE, 'HH24:MI')",
data1 POSITION(1:5) ":data1/100",
data2 POSITION(6:15) "upper(:data2)",
data3 POSITION(16:22)"to_date(:data3, 'YYMMDD')"
)
BEGINDATA
11111AAAAAAAAAA991201
22222BBBBBBBBBB990112
LOAD DATA
INFILE 'mail_orders.txt'
BADFILE 'bad_orders.txt'
APPEND
INTO TABLE mailing_list
FIELDS TERMINATED BY ","
( addr,
city,
state,
zipcode,
mailing_addr "decode(:mailing_addr, null, :addr, :mailing_addr)",
mailing_city "decode(:mailing_city, null, :city, :mailing_city)",
mailing_state
)
Can one load data from multiple files/ into multiple tables at once?
Loading from multiple input files
One can load from multiple input files provided they use the same record format by repeating the INFILE clause. Here is an example: LOAD DATA
INFILE file1.dat
INFILE file2.dat
INFILE file3.dat
APPEND
INTO TABLE emp
( empno POSITION(1:4) INTEGER EXTERNAL,
ename POSITION(6:15) CHAR,
deptno POSITION(17:18) CHAR,
mgr POSITION(20:23) INTEGER EXTERNAL
)
Loading into multiple tables
One can also specify multiple "INTO TABLE" clauses in the SQL*Loader control file to load into multiple tables. Look at the following example: LOAD DATA
INFILE *
INTO TABLE tab1 WHEN tab = 'tab1'
( tab FILLER CHAR(4),
col1 INTEGER
)
INTO TABLE tab2 WHEN tab = 'tab2'
( tab FILLER POSITION(1:4),
col1 INTEGER
)
BEGINDATA
tab11
tab12
tab22
tab33
The "tab" field is marked as a FILLER as we don't want to load it.
Note the use of "POSITION" on the second routing value (tab = 'tab2'). By default field scanning doesn't start over from the beginning of the record for new INTO TABLE clauses. Instead, scanning continues where it left off. POSITION is needed to reset the pointer to the beginning of the record again.
Another example: LOAD DATA
INFILE 'mydata.dat'
REPLACE
INTO TABLE emp
WHEN empno != ' '
( empno POSITION(1:4) INTEGER EXTERNAL,
ename POSITION(6:15) CHAR,
deptno POSITION(17:18) CHAR,
mgr POSITION(20:23) INTEGER EXTERNAL
)
INTO TABLE proj
WHEN projno != ' '
( projno POSITION(25:27) INTEGER EXTERNAL,
empno POSITION(1:4) INTEGER EXTERNAL
)
Can one selectively load only the records that one need?Look at this example, (01) is the first character, (30:37) are characters 30 to 37: LOAD DATA
INFILE 'mydata.dat' BADFILE 'mydata.bad' DISCARDFILE 'mydata.dis'
APPEND
INTO TABLE my_selective_table
WHEN (01) <> 'H' and (01) <> 'T' and (30:37) = '20031217'
(
region CONSTANT '31',
service_key POSITION(01:11) INTEGER EXTERNAL,
call_b_no POSITION(12:29) CHAR
)
NOTE: SQL*Loader does not allow the use of OR in the WHEN clause. You can only use AND as in the example above! To workaround this problem, code multiple "INTO TABLE ... WHEN" clauses. Here is an example: LOAD DATA
INFILE 'mydata.dat' BADFILE 'mydata.bad' DISCARDFILE 'mydata.dis'
APPEND
INTO TABLE my_selective_table
WHEN (01) <> 'H' and (01) <> 'T'
(
region CONSTANT '31',
service_key POSITION(01:11) INTEGER EXTERNAL,
call_b_no POSITION(12:29) CHAR
)
INTO TABLE my_selective_table
WHEN (30:37) = '20031217'
(
region CONSTANT '31',
service_key POSITION(01:11) INTEGER EXTERNAL,
call_b_no POSITION(12:29) CHAR
)
Can one skip certain columns while loading data?One cannot use POSITION(x:y) with delimited data. Luckily, from Oracle 8i one can specify FILLER columns. FILLER columns are used to skip columns/fields in the load file, ignoring fields that one does not want. Look at this example: LOAD DATA
TRUNCATE INTO TABLE T1
FIELDS TERMINATED BY ','
( field1,
field2 FILLER,
field3
)
How does one load multi-line records?One can create one logical record from multiple physical records using one of the following two clauses:
CONCATENATE - use when SQL*Loader should combine the same number of physical recordstogether to form one logical record.
CONTINUEIF - use if a condition indicates that multiple records should be treated as one. Eg. by having a '#' character in column 1.
How can one get SQL*Loader to COMMIT only at the end of the load file?One cannot, but by setting the ROWS= parameter to a large value, committing can be reduced. Make sure you have big rollback segments ready when you use a high value for ROWS=.
Can one improve the performance of SQL*Loader?
A very simple but easily overlooked hint is not to have any indexes and/or constraints (primary key) on your load tables during the load process. This will significantly slow down load times even with ROWS= set to a high value.
Add the following option in the command line: DIRECT=TRUE. This will effectively bypass most of the RDBMS processing. However, there are cases when you can't use direct load. For details, refer to the FAQ about the differences between the conventional and direct path loader below.
Turn off database logging by specifying the UNRECOVERABLE option. This option can only be used with direct data loads.
Run multiple load jobs concurrently.
What is the difference between the conventional and direct path loader?The conventional path loader essentially loads the data by using standard INSERT statements. The direct path loader (DIRECT=TRUE) bypasses much of the logic involved with that, and loads directly into the Oracle data files. More information about the restrictions of direct path loading can be obtained from the Oracle Server Utilities Guide (see chapter 8).
Some of the restrictions with direct path loads are:
Loaded data will not be replicated
Cannot always use SQL strings for column processing in the control file (something like this will probably fail: col1 date "ddmonyyyy" "substr(:period,1,9)"). Details are in Metalink Note:230120.1.
How does one use SQL*Loader to load images, sound clips and documents?
Any one has more information on this section please put forward ..SQL*Loader can load data from a "primary data file", SDF (Secondary Data file - for loading nested tables and VARRAYs) or LOBFILE. The LOBFILE method provides an easy way to load documents, photos, images and audio clips into BLOB and CLOB columns. Look at this example:
Given the following table: CREATE TABLE image_table (
image_id NUMBER(5),
file_name VARCHAR2(30),
image_data BLOB);
Control File: LOAD DATA
INFILE *
INTO TABLE image_table
REPLACE
FIELDS TERMINATED BY ','
(
image_id INTEGER(5),
file_name CHAR(30),
image_data LOBFILE (file_name) TERMINATED BY EOF
)
BEGINDATA
001,image1.gif
002,image2.jpg
003,image3.jpg
How does one load EBCDIC data?Specify the character set WE8EBCDIC500 for the EBCDIC data. The following example shows the SQL*Loader controlfile to load a fixed length EBCDIC record into the Oracle Database: LOAD DATA
CHARACTERSET WE8EBCDIC500
INFILE data.ebc "fix 86 buffers 1024"
BADFILE data.bad'
DISCARDFILE data.dsc'
REPLACE
INTO TABLE temp_data
(
field1 POSITION (1:4) INTEGER EXTERNAL,
field2 POSITION (5:6) INTEGER EXTERNAL,
field3 POSITION (7:12) INTEGER EXTERNAL,
field4 POSITION (13:42) CHAR,
field5 POSITION (43:72) CHAR,
field6 POSITION (73:73) INTEGER EXTERNAL,
field7 POSITION (74:74) INTEGER EXTERNAL,
field8 POSITION (75:75) INTEGER EXTERNAL,
field9 POSITION (76:86) INTEGER EXTERNAL
)
