write blob to file

From: Jeff Chirco <JChirco_at_innout.com>
Date: Tue, 21 Aug 2012 15:43:06 +0000
Message-ID: <6D9F00643B733E489E419CB485C9662734248F_at_IRVMBX01.innout.corp>

We have pdf's stored in our database as blob as a secure file which is encrypted and we want to write these blobs out to the file system. I have written this procedure below but it is very slow. The files range from about 90kb to 500kb. I did a test with 10 files and it writes the first two files instantly which happened to be the biggest files 440kb and 180kb but then starts to slow down for each of the next files (which are all around 90kb) and by the time it gets to the 10 file it is crawling. It took about 10 minutes to all 10 files. Am I doing something wrong in this procedure? Is there a better way? Thanks

create or replace procedure SAVE_TO_FILE_FILE IS

l_file UTL_FILE.FILE_TYPE;
l_buffer RAW(32767);
l_amount BINARY_INTEGER := 32767;
l_pos INTEGER := 1;
l_blob_len INTEGER;

CURSOR C1 IS SELECT dbID || '.pdf' file_name, dbdoc From scanner_user.documents Where dbid IN (345710,

668760,
738977,
333767,
372326,
335241,
627734,
782436,
535041,

472812);

BEGIN FOR I IN C1 LOOP
-- Get LOB locator
--SELECT dbdoc, dbid || '.pdf' INTO l_blob,MYFILE_NAME FROM scanner_user.documents where dbID= I.dbID;

l_blob_len := DBMS_LOB.getlength(i.dbdoc); l_pos:= 1;
-- Open the destination file.

l_file := UTL_FILE.fopen('DIR_EXPORT',i.FILE_NAME,'wb', 32767);

• Read chunks of the BLOB and write them to the file
• until complete. WHILE l_pos < l_blob_len LOOP DBMS_LOB.read(i.dbdoc, l_amount, l_pos, l_buffer); UTL_FILE.put_raw(l_file, l_buffer, TRUE); l_pos := l_pos + l_amount; END LOOP;
• Close the file. UTL_FILE.fclose(l_file);

END LOOP;
EXCEPTION
WHEN OTHERS THEN
-- Close the file if something goes wrong.
IF UTL_FILE.is_open(l_file) THEN
UTL_FILE.fclose(l_file);
END IF;
RAISE; end SAVE_TO_FILE_FILE;

--

http://www.freelists.org/webpage/oracle-l Received on Tue Aug 21 2012 - 10:43:06 CDT