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How can we load data into CLOB datatype column using SQL Loader?

NirvanFeb 5 2021

Hi Experts-
We have a tab delimiter file which will be received on timely basis, apart from other column values there is one column which contains huge data which I am trying to load into a clob column, and we are not sure how big the data will be in that column as it is not specified. Currently I am trying to load the data by extending the size of the column in control file every time which may not be good practice. Could you please let me know if there is any other possibility to load the data without specifying the size. I tried searching for a solution everything I found is about lobfile which may not help here as we are not receiving the data in a separately alone for the specific column.
--For example the table structure looks like this.
CREATE TABLE TMP_LOAD_CLOB_DATA
(
CUSTOMER_ID VARCHAR2(255),
FIRSTNAME VARCHAR2(255),
LASTNAME VARCHAR2(255),
CUSTOMER_DETAILS CLOB
);
--Assuming the data will look like shown below.
CUSTOMER_ID FIRSTNAME LASTNAME CUSTOMER_DETAILS
123 ABC XYZ Lot Of Information about the customer which should be loaded into clob
--The control file will look like this
OPTIONS (DIRECT=TRUE, MULTITHREADING=TRUE, PARALLEL=TRUE)
load data
infile '/test.txt'
into table TMP_LOAD_CLOB_DATA
APPEND
fields terminated by X'09'
trailing nullcols
(CUSTOMER_ID,
FIRSTNAME,
LASTNAME,
CUSTOMER_DETAILS char(50000))

How can I avoid adding the column size like char(50000) and still load the data into clob column?
Thank you,
Nirvan
This post has been answered by Solomon Yakobson on Feb 5 2021
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Comments

Solomon Yakobson
Answer

Well, since CLOB in general is multi-line text each clob needs to be stored as a separate file. So we prepare CTL file:

LOAD DATA
INFILE 'C:\TEMP\TMP_LOAD_CLOB_DATA.TXT'
  INTO TABLE TMP_LOAD_CLOB_DATA
  FIELDS TERMINATED BY X'09'
  (
   CUSTOMER_ID,
   FIRSTNAME,
   LASTNAME,
   CUSTOMER_DETAILS_CLOB_FILE FILLER,
   CUSTOMER_DETAILS LOBFILE(CUSTOMER_DETAILS_CLOB_FILE) TERMINATED BY EOF
  )

Data file C:\TEMP\TMP_LOAD_CLOB_DATA.TXT:

123	ABC	XYZ	C:\TEMP\TMP_LOAD_CLOB1.TXT
456	DEF	ZZZ	C:\TEMP\TMP_LOAD_CLOB2.TXT

Clob file C:\TEMP\TMP_LOAD_CLOB1.TXT:

Lot Of Information 
about customer ABC XYZ
which should be loaded
into a clob

Clob file C:\TEMP\TMP_LOAD_CLOB2.TXT:

Lot Of Information 
about customer DEF ZZZ
which should be loaded
into a clob

Now:

SQL> SELECT  *
  2    FROM  TMP_LOAD_CLOB_DATA
  3  /

no rows selected

SQL> host
Microsoft Windows [Version 10.0.17763.1637]
(c) 2018 Microsoft Corporation. All rights reserved.

I:\>sqlldr scott@pdb1sol122/tiger control=C:\TEMP\TMP_LOAD_CLOB_DATA.ctl

SQL*Loader: Release 12.2.0.1.0 - Production on Fri Feb 5 07:25:12 2021

Copyright (c) 1982, 2017, Oracle and/or its affiliates.  All rights reserved.

Path used:      Conventional
Commit point reached - logical record count 2

Table TMP_LOAD_CLOB_DATA:
  2 Rows successfully loaded.

Check the log file:
  TMP_LOAD_CLOB_DATA.log
for more information about the load.

I:\>exit

SQL> SELECT  *
  2    FROM  TMP_LOAD_CLOB_DATA
  3  /


CUSTOMER_ID FIRSTNAME LASTNAME CUSTOMER_DETAILS
----------- --------- -------- ------------------------------
123         ABC       XYZ      Lot Of Information
                               about customer ABC XYZ
                               which should be loaded
                               into a clob

456         DEF       ZZZ      Lot Of Information
                               about customer DEF ZZZ
                               which should be loaded
                               into a clob

SQL>

SY.

Marked as Answer by Nirvan · Feb 22 2021
1 person found this helpful
Nirvan

Hi Solomon, Thank you for your response..

User_ZZAIV

Hi,
For above is there any way to load CLOB data without having separate files ??

User_H3J7U

To load lobs, use the insert, update, or merge statement.

User_48D4R

What to do when a large text is part of a single file and needs to be inserted with an SQLLDR.
eg: it is 498,780 characters long.
ID | VALUE | DATA
1 | Dr4wQQ | it is 498,780 characters long......
2 | WQWQ3 | it is 925,342 characters long......
3 | DERRQQ | it is 478,998 characters long......

Solomon Yakobson

I'll assume CLOB doesn't start with new line. I will also assume, based on your data sample, vertical pipe can't appear in CLOB - otherwise you simply can't use it as field separator. If so, control file TMP_LOAD_CLOB_DATA.CTL:

LOAD DATA
  INFILE 'C:\MY_TEMP\TMP_LOAD_CLOB_DATA.TXT'
  "str X'7C0D0A'"
  INTO TABLE TMP_LOAD_CLOB_DATA
  FIELDS TERMINATED BY "|"
  (
   ID,
   VALUE,
   DATA
  )

7C is hex ascii code for vertical pipe. 0D0A is new line (CRLF - carriage return, line feed). Now we need to add vertical pipe at the end of each line in data file TMP_LOAD_CLOB_DATA.TXT:

1 | Dr4wQQ | it
 is 498,780
 characters
 long......|
2 | WQWQ3 | it 
is 
925,342
 characters long......|
3 | DERRQQ | it 
is 
478,998
 characters
 long
 line1
 line2
 many
 more
 lines|

Now we load:

I:\>sqlldr scott@xxx/yyy control=c:\my_temp\tmp_load_clob_data.ctl log=c:\my_temp\tmp_load_clob_data.log

SQL*Loader: Release 12.2.0.1.0 - Production on Fri Aug 12 06:55:18 2022

Copyright (c) 1982, 2017, Oracle and/or its affiliates.  All rights reserved.

Path used:      Conventional
Commit point reached - logical record count 2
Commit point reached - logical record count 3

Table TMP_LOAD_CLOB_DATA:
  3 Rows successfully loaded.

Check the log file:
  c:\my_temp\tmp_load_clob_data.log
for more information about the load.

I:\>

Now we check what was loaded:

SQL> select * from tmp_load_clob_data;

        ID VALUE      DATA
---------- ---------- ----------------------------------------
         1  Dr4wQQ     it
                       is 498,780
                       characters
                       long......

         2  WQWQ3      it
                      is
                      925,342
                       characters long......

         3  DERRQQ     it
                      is
                      478,998
                       characters
                       long
                       line1
                       line2
                       many
                       more
                       lines

SQL>

SY.

Gor_Mahia


Gor_Mahia

Hi
Did you get a solid solution to this issue? It seems splitting CLOB field isn't that helpful since you still need a unique key to merger them back?

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Added on Feb 5 2021
#oracle, #sql
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