◉ Prerequisites
Most of the examples in this article use an on-prem installation of the DBMS_CLOUD package, but some functionality only seems to work properly on the Autonomous Database. We'll highlight when one of these restrictions is in place.
The DBMS_CLOUD package is present by default on the Autonomous Database. It is not installed in Oracle 19c or 21c installations, so it has to be installed manually. The installation is described in this MOS note.
There is an example of this installation here.
We need an object store bucket for some of the examples. This could be an Oracle Cloud Object Store bucket, or an AWS S3 bucket. The following article describes how to create an Oracle Cloud Object Store bucket.
◉ Setup
We create a test user. We make sure the user can create credentials, and give it access to the DBMS_CLOUD package.
conn sys/SysPassword1@//localhost:1521/pdb1 as sysdba
--drop user testuser1 cascade;
create user testuser1 identified by testuser1 quota unlimited on users;
grant connect, resource to testuser1;
grant create credential to testuser1;
grant execute on dbms_cloud to testuser1;
We need a local directory object to interact with files on the database file server. We give both the test user and C##CLOUD$SERVICE user access to this directory.
create or replace directory tmp_files_dir as '/tmp/files';
grant read, write on directory tmp_files_dir to testuser1, C##CLOUD$SERVICE;
The external table functionality requires access to a directory object called DATA_PUMP_DIR, so create it in the PDB and grant read/write access to the test user.
alter session set "_oracle_script"=TRUE;
create or replace directory data_pump_dir as '/u01/app/oracle/admin/cdb1/dpdump/';
alter session set "_oracle_script"=FALSE;
grant read, write on directory data_pump_dir to testuser1;
Connect to the test user and create the following table.
conn testuser1/testuser1@//localhost:1521/pdb1
create table emp (
empno number(4,0),
ename varchar2(10 byte),
job varchar2(9 byte),
mgr number(4,0),
hiredate date,
sal number(7,2),
comm number(7,2),
deptno number(2,0),
constraint pk_emp primary key (empno)
);
insert into emp (empno,ename,job,mgr,hiredate,sal,comm,deptno) values (7369,'SMITH','CLERK',7902,to_date('17-DEC-80','DD-MON-RR'),800,null,20);
insert into emp (empno,ename,job,mgr,hiredate,sal,comm,deptno) values (7499,'ALLEN','SALESMAN',7698,to_date('20-FEB-81','DD-MON-RR'),1600,300,30);
insert into emp (empno,ename,job,mgr,hiredate,sal,comm,deptno) values (7521,'WARD','SALESMAN',7698,to_date('22-FEB-81','DD-MON-RR'),1250,500,30);
insert into emp (empno,ename,job,mgr,hiredate,sal,comm,deptno) values (7566,'JONES','MANAGER',7839,to_date('02-APR-81','DD-MON-RR'),2975,null,20);
insert into emp (empno,ename,job,mgr,hiredate,sal,comm,deptno) values (7654,'MARTIN','SALESMAN',7698,to_date('28-SEP-81','DD-MON-RR'),1250,1400,30);
insert into emp (empno,ename,job,mgr,hiredate,sal,comm,deptno) values (7698,'BLAKE','MANAGER',7839,to_date('01-MAY-81','DD-MON-RR'),2850,null,30);
insert into emp (empno,ename,job,mgr,hiredate,sal,comm,deptno) values (7782,'CLARK','MANAGER',7839,to_date('09-JUN-81','DD-MON-RR'),2450,null,10);
insert into emp (empno,ename,job,mgr,hiredate,sal,comm,deptno) values (7788,'SCOTT','ANALYST',7566,to_date('19-APR-87','DD-MON-RR'),3000,null,20);
insert into emp (empno,ename,job,mgr,hiredate,sal,comm,deptno) values (7839,'KING','PRESIDENT',null,to_date('17-NOV-81','DD-MON-RR'),5000,null,10);
insert into emp (empno,ename,job,mgr,hiredate,sal,comm,deptno) values (7844,'TURNER','SALESMAN',7698,to_date('08-SEP-81','DD-MON-RR'),1500,0,30);
insert into emp (empno,ename,job,mgr,hiredate,sal,comm,deptno) values (7876,'ADAMS','CLERK',7788,to_date('23-MAY-87','DD-MON-RR'),1100,null,20);
insert into emp (empno,ename,job,mgr,hiredate,sal,comm,deptno) values (7900,'JAMES','CLERK',7698,to_date('03-DEC-81','DD-MON-RR'),950,null,30);
insert into emp (empno,ename,job,mgr,hiredate,sal,comm,deptno) values (7902,'FORD','ANALYST',7566,to_date('03-DEC-81','DD-MON-RR'),3000,null,20);
insert into emp (empno,ename,job,mgr,hiredate,sal,comm,deptno) values (7934,'MILLER','CLERK',7782,to_date('23-JAN-82','DD-MON-RR'),1300,null,10);
commit;
All SQL operations in this article will be performed from the test user, unless otherwise stated.
conn testuser1/testuser1@//localhost:1521/pdb1
◉ Object Store URIs
We use an object store URI for many of the examples in this article. For Oracle Cloud the URI can take either of these forms.
https://swiftobjectstorage.{region}.oraclecloud.com/v1/{namespace}/{bucket}/{objectname}
https://objectstorage.{region}.oraclecloud.com/n/{namespace}/b/{bucket}/o/{objectname}
The documentation typically uses the "swiftobjectstorage" URI, but both work. For the remainder of the article we will use the "swiftobjectstorage" URI.
The AWS S3 and Azure blob storage URIs typically look like this.
AWS S3: https://s3-{region}.amazonaws.com/{bucket}/{objectname}
Azure Blog Storage: https://{account}.blob.core.windows.net/{container}/{objectname}
A number of the procedures and functions support wildcards in the URI definitions.
- * - A wildcard for multiple characters.
- ? - A wildcard for a single character.
◉ Object Store Credentials
The DBMS_CLOUD package contains a copy of the procedures from the DBMS_CREDENTIAL package. The two packages can be used interchangeably, as they do the same thing.
Create a credential for your object store using the CREATE_CREDENTIAL procedure. For an Oracle object storage bucket we use our Oracle Cloud email and the Auth Token we generated.
begin
dbms_cloud.create_credential (
credential_name => 'obj_store_cred',
username => 'me@example.com',
password => '{my-Auth-Token}'
) ;
end;
/
For AWS buckets we use our AWS access key and secret access key.
begin
dbms_cloud.create_credential (
credential_name => 'obj_store_cred',
username => 'my AWS access key',
password => 'my AWS secret access key'
);
end;
/
Information about the credential can be displayed using the USER_CREDENTIALS view.
column credential_name format a25
column username format a20
select credential_name,
username,
enabled
from user_credentials
order by credential_name;
CREDENTIAL_NAME USERNAME ENABL
------------------------- -------------------- -----
OBJ_STORE_CRED me@example.com TRUE
SQL>
The DISABLE_CREDENTIAL and ENABLE_CREDENTIAL procedures disable and enable credentials respectively.
begin
dbms_credential.disable_credential('obj_store_cred');
dbms_credential.enable_credential('obj_store_cred');
end;/
The UPDATE_CREDENTIALS procedure allows us to edit attributes of a credential.
begin
dbms_credential.update_credential(
credential_name => 'obj_store_cred',
attribute => 'username',
value => 'me@example.com');
dbms_credential.update_credential(
credential_name => 'obj_store_cred',
attribute => 'password',
value => '{my-Auth-Token}');
end;
/
The DROP_CREDENTIAL procedure drops the named credential.
begin
dbms_cloud.drop_credential(credential_name => 'obj_store_cred');
end;
/
The following examples require a valid credential.
◉ Objects and Files
There are several routines for manipulating files on the local database file system and objects in a cloud object store.
Create a file on the database server file system.
mkdir -p /tmp/files
echo "This is a test file" > /tmp/files/test1.txt
We use the PUT_OBJECT procedure to transfer a file from the directory object location to the cloud object store.
begin
dbms_cloud.put_object (
credential_name => 'obj_store_cred',
object_uri => 'https://swiftobjectstorage.uk-london-1.oraclecloud.com/v1/my-namespace/ob-bucket/test1.txt',
directory_name => 'tmp_files_dir',
file_name => 'test1.txt');
end;
/
There is an overload of the PUT_OBJECT procedure to transfer the contents of a BLOB to the object store.
declare
l_file blob;
begin
l_file := utl_raw.cast_to_raw('This is another test file');
dbms_cloud.put_object (
credential_name => 'obj_store_cred',
object_uri => 'https://swiftobjectstorage.uk-london-1.oraclecloud.com/v1/my-namespace/ob-bucket/test2.txt',
contents => l_file);
end;
/
The LIST_OBJECTS table function lists objects in the location pointed to by the object store URI.
set linesize 150
column object_name format a12
column checksum format a35
column created format a35
column last_modified format a35
select *
from dbms_cloud.list_objects(
credential_name => 'obj_store_cred',
location_uri => 'https://swiftobjectstorage.uk-london-1.oraclecloud.com/v1/my-namespace/ob-bucket');
OBJECT_NAME BYTES CHECKSUM CREATED LAST_MODIFIED
------------ ---------- ----------------------------------- ----------------------------------- -----------------------------------
test1.txt 20 5dd39cab1c53c2c77cd352983f9641e1 11-SEP-21 08.45.42.779000 AM +00:00
test2.txt 25 d0914057907f9d04dd9e68b1c1e180f0 11-SEP-21 08.45.54.148000 AM +00:00
SQL>
We use the GET_METADATA function to return information about a specific object.
select dbms_cloud.get_metadata(
credential_name => 'obj_store_cred',
object_uri => 'https://swiftobjectstorage.uk-london-1.oraclecloud.com/v1/my-namespace/ob-bucket/test2.txt') as metadata
from dual;
METADATA
--------------------------------------------------------------------------------
{"Content-Length":25}
SQL>
We use the GET_OBJECT procedure to transfer an object from the cloud object store to the directory object location.
begin
dbms_cloud.get_object (
credential_name => 'obj_store_cred',
object_uri => 'https://swiftobjectstorage.uk-london-1.oraclecloud.com/v1/my-namespace/ob-bucket/test2.txt',
directory_name => 'tmp_files_dir',
file_name => 'test2.txt');
end;
/
There is a GET_OBJECT function to transfer an object from the cloud object store to a BLOB.
declare
l_file blob;
begin
l_file := dbms_cloud.get_object (
credential_name => 'obj_store_cred',
object_uri => 'https://swiftobjectstorage.uk-london-1.oraclecloud.com/v1/my-namespace/ob-bucket/test2.txt');
end;
/
The DELETE_OBJECT procedure deletes objects from the cloud object store.
begin
dbms_cloud.delete_object(
credential_name => 'obj_store_cred',
object_uri => 'https://swiftobjectstorage.uk-london-1.oraclecloud.com/v1/my-namespace/ob-bucket/test1.txt');
dbms_cloud.delete_object(
credential_name => 'obj_store_cred',
object_uri => 'https://swiftobjectstorage.uk-london-1.oraclecloud.com/v1/my-namespace/ob-bucket/test2.txt');
end;
/
The DELETE_FILE procedure deletes files from directory object location.
begin
dbms_cloud.delete_file(
directory_name => 'tmp_files_dir',
file_name => 'test1.txt');
dbms_cloud.delete_file(
directory_name => 'tmp_files_dir',
file_name => 'test2.txt');
end;
/
The LIST_FILES table function lists the files in the location pointed to by the specified Oracle directory object. The documentation says it's only supported for directory objects mapping to Oracle File System (OFS) or Database File System (DBFS) file systems, so we can't use it for a regular file system. It does work in the locations provided on the Autonomous Database.
select *
from dbms_cloud.list_files(directory_name => 'data_pump_dir');
◉ External Tables
This section describes the creation of external tables based on files in a cloud object store.
◉ CREATE_EXTERNAL_TABLE
We create a file called "emp.dat" with the following contents and place it into our object store. It is a pipe-delimited file with no headers.
7369|"SMITH"|"CLERK"|7902|17-DEC-80|800||20
7499|"ALLEN"|"SALESMAN"|7698|20-FEB-81|1600|300|30
7521|"WARD"|"SALESMAN"|7698|22-FEB-81|1250|500|30
7566|"JONES"|"MANAGER"|7839|02-APR-81|2975||20
7654|"MARTIN"|"SALESMAN"|7698|28-SEP-81|1250|1400|30
7698|"BLAKE"|"MANAGER"|7839|01-MAY-81|2850||30
7782|"CLARK"|"MANAGER"|7839|09-JUN-81|2450||10
7788|"SCOTT"|"ANALYST"|7566|19-APR-87|3000||20
7839|"KING"|"PRESIDENT"||17-NOV-81|5000||10
7844|"TURNER"|"SALESMAN"|7698|08-SEP-81|1500|0|30
7876|"ADAMS"|"CLERK"|7788|23-MAY-87|1100||20
7900|"JAMES"|"CLERK"|7698|03-DEC-81|950||30
7902|"FORD"|"ANALYST"|7566|03-DEC-81|3000||20
7934|"MILLER"|"CLERK"|7782|23-JAN-82|1300||10
The CREATE_EXTERNAL_TABLE procedure creates an external table called EMP_EXT based on a file in a cloud object store.
--drop table emp_ext;
begin
dbms_cloud.create_external_table(
table_name => 'emp_ext',
credential_name => 'obj_store_cred',
file_uri_list => 'https://swiftobjectstorage.uk-london-1.oraclecloud.com/v1/my-namespace/ob-bucket/emp.dat',
column_list => 'empno number(4),
ename varchar2(10),
job varchar2(9),
mgr number(4),
hiredate date,
sal number(7,2),
comm number(7,2),
deptno number(2)',
format => json_object('ignoremissingcolumns' value 'true', 'removequotes' value 'true')
);
end;
/
We query the external table, which reads the data from the cloud object store.
select * from emp_ext;
EMPNO ENAME JOB MGR HIREDATE SAL COMM DEPTNO
---------- ---------- --------- ---------- --------- ---------- ---------- ----------
7369 SMITH CLERK 7902 17-DEC-80 800 20
7499 ALLEN SALESMAN 7698 20-FEB-81 1600 300 30
7521 WARD SALESMAN 7698 22-FEB-81 1250 500 30
7566 JONES MANAGER 7839 02-APR-81 2975 20
7654 MARTIN SALESMAN 7698 28-SEP-81 1250 1400 30
7698 BLAKE MANAGER 7839 01-MAY-81 2850 30
7782 CLARK MANAGER 7839 09-JUN-81 2450 10
7788 SCOTT ANALYST 7566 19-APR-87 3000 20
7839 KING PRESIDENT 17-NOV-81 5000 10
7844 TURNER SALESMAN 7698 08-SEP-81 1500 0 30
7876 ADAMS CLERK 7788 23-MAY-87 1100 20
7900 JAMES CLERK 7698 03-DEC-81 950 30
7902 FORD ANALYST 7566 03-DEC-81 3000 20
7934 MILLER CLERK 7782 23-JAN-82 1300 10
14 rows selected.
SQL>
The FORMAT parameter allows us to tailor the load process to to suit the data file contents. The full list of format options can be found here. The following example works with a CSV file.
We create a file called "emp.csv" with the following contents and place it into our object store. It is a CSV file with a header row.
"EMPNO","ENAME","JOB","MGR","HIREDATE","SAL","COMM","DEPTNO"
7369,"SMITH","CLERK",7902,17-DEC-80,800,,20
7499,"ALLEN","SALESMAN",7698,20-FEB-81,1600,300,30
7521,"WARD","SALESMAN",7698,22-FEB-81,1250,500,30
7566,"JONES","MANAGER",7839,02-APR-81,2975,,20
7654,"MARTIN","SALESMAN",7698,28-SEP-81,1250,1400,30
7698,"BLAKE","MANAGER",7839,01-MAY-81,2850,,30
7782,"CLARK","MANAGER",7839,09-JUN-81,2450,,10
7788,"SCOTT","ANALYST",7566,19-APR-87,3000,,20
7839,"KING","PRESIDENT",,17-NOV-81,5000,,10
7844,"TURNER","SALESMAN",7698,08-SEP-81,1500,0,30
7876,"ADAMS","CLERK",7788,23-MAY-87,1100,,20
7900,"JAMES","CLERK",7698,03-DEC-81,950,,30
7902,"FORD","ANALYST",7566,03-DEC-81,3000,,20
7934,"MILLER","CLERK",7782,23-JAN-82,1300,,10
The CREATE_EXTERNAL_TABLE procedure creates an external table called EMP_CSV_EXT based on a file in a cloud object store.
--drop table emp_csv_ext;
begin
dbms_cloud.create_external_table(
table_name => 'emp_csv_ext',
credential_name => 'obj_store_cred',
file_uri_list => 'https://swiftobjectstorage.uk-london-1.oraclecloud.com/v1/my-namespace/ob-bucket/emp.csv',
column_list => 'empno number(4),
ename varchar2(10),
job varchar2(9),
mgr number(4),
hiredate date,
sal number(7,2),
comm number(7,2),
deptno number(2)',
format => json_object('type' value 'csv', 'skipheaders' value '1')
);
end;
/
We query the external table, which reads the data from the cloud object store.
select * from emp_csv_ext;
EMPNO ENAME JOB MGR HIREDATE SAL COMM DEPTNO
---------- ---------- --------- ---------- --------- ---------- ---------- ----------
7369 SMITH CLERK 7902 17-DEC-80 800 20
7499 ALLEN SALESMAN 7698 20-FEB-81 1600 300 30
7521 WARD SALESMAN 7698 22-FEB-81 1250 500 30
7566 JONES MANAGER 7839 02-APR-81 2975 20
7654 MARTIN SALESMAN 7698 28-SEP-81 1250 1400 30
7698 BLAKE MANAGER 7839 01-MAY-81 2850 30
7782 CLARK MANAGER 7839 09-JUN-81 2450 10
7788 SCOTT ANALYST 7566 19-APR-87 3000 20
7839 KING PRESIDENT 17-NOV-81 5000 10
7844 TURNER SALESMAN 7698 08-SEP-81 1500 0 30
7876 ADAMS CLERK 7788 23-MAY-87 1100 20
7900 JAMES CLERK 7698 03-DEC-81 950 30
7902 FORD ANALYST 7566 03-DEC-81 3000 20
7934 MILLER CLERK 7782 23-JAN-82 1300 10
14 rows selected.
SQL>
The VALIDATE_EXTERNAL_TABLE procedure allows us to check the validity of an external table.
begin
dbms_cloud.validate_external_table('emp_csv_ext');
end;
/
◉ CREATE_EXTERNAL_PART_TABLE
Create four CSV files using the following queries.
set markup csv on quote on
set trimspool on linesize 1000 feedback off pagesize 0
spool /tmp/files/gbr1.txt
select 'GBR',
object_id,
owner,
object_name
from all_objects
where object_id <= 2000
and rownum <= 1000;
spool off
spool /tmp/files/gbr2.txt
select 'GBR',
object_id,
owner,
object_name
from all_objects
where object_id BETWEEN 2000 AND 3999
and rownum <= 1000;
spool off
spool /tmp/files/ire1.txt
select 'IRE',
object_id,
owner,
object_name
from all_objects
where object_id <= 2000
and rownum <= 1000;
spool off
spool /tmp/files/ire2.txt
select 'IRE',
object_id,
owner,
object_name
from all_objects
where object_id BETWEEN 2000 AND 3999
and rownum <= 1000;
spool off
set markup csv off
set trimspool on linesize 1000 feedback off pagesize 14
You may need to clean up the start and end of the files a little before uploading them. Copy the files to the object store.
begin
dbms_cloud.put_object (
credential_name => 'obj_store_cred',
object_uri => 'https://swiftobjectstorage.uk-london-1.oraclecloud.com/v1/my-namespace/ob-bucket/gbr1.txt',
directory_name => 'tmp_files_dir',
file_name => 'gbr1.txt');
end;
/
begin
dbms_cloud.put_object (
credential_name => 'obj_store_cred',
object_uri => 'https://swiftobjectstorage.uk-london-1.oraclecloud.com/v1/my-namespace/ob-bucket/gbr2.txt',
directory_name => 'tmp_files_dir',
file_name => 'gbr2.txt');
end;
/
begin
dbms_cloud.put_object (
credential_name => 'obj_store_cred',
object_uri => 'https://swiftobjectstorage.uk-london-1.oraclecloud.com/v1/my-namespace/ob-bucket/ire1.txt',
directory_name => 'tmp_files_dir',
file_name => 'ire1.txt');
end;
/
begin
dbms_cloud.put_object (
credential_name => 'obj_store_cred',
object_uri => 'https://swiftobjectstorage.uk-london-1.oraclecloud.com/v1/my-namespace/ob-bucket/ire2.txt',
directory_name => 'tmp_files_dir',
file_name => 'ire2.txt');
end;
/
The CREATE_EXTERNAL_PART_TABLE procedure creates an external partitioned table called COUNTRY_PART_TAB_EXT based on a files in a cloud object store.
--drop table country_part_tab_ext;
begin
dbms_cloud.create_external_part_table(
table_name => 'country_part_tab_ext',
credential_name => 'obj_store_cred',
format => json_object('type' value 'csv', 'skipheaders' value '1'),
column_list => 'country_code varchar2(3),
object_id number,
owner varchar2(128),
object_name varchar2(128)',
partitioning_clause => 'partition by list (country_code) (
partition part_gbr values (''GBR'') location (
''https://swiftobjectstorage.uk-london-1.oraclecloud.com/v1/my-namespace/ob-bucket/gbr1.txt'',
''https://swiftobjectstorage.uk-london-1.oraclecloud.com/v1/my-namespace/ob-bucket/gbr2.txt''
),
partition part_ire values (''IRE'') location (
''https://swiftobjectstorage.uk-london-1.oraclecloud.com/v1/my-namespace/ob-bucket/ire1.txt'',
''https://swiftobjectstorage.uk-london-1.oraclecloud.com/v1/my-namespace/ob-bucket/ire2.txt''
)
)'
);
end;
/
We query the external table, which reads the data from the cloud object store.
select country_code, count(*) as amount
from country_part_tab_ext
group by country_code
order by country_code;
COU AMOUNT
--- ----------
GBR 2000
IRE 2000
SQL>
The VALIDATE_EXTERNAL_PART_TABLE procedure allows us to check the validity of an external partitioned table.
begin
dbms_cloud.validate_external_part_table('country_part_tab_ext');
end;
/
◉ CREATE_HYBRID_PART_TABLE
The CREATE_HYBRID_PART_TABLE procedure creates an external hybrid partitioned table called COUNTRY_HYBRID_PART_TAB_EXT based on a files in a cloud object store.
--drop table country_hybrid_part_tab_ext;
begin
dbms_cloud.create_hybrid_part_table(
table_name => 'country_hybrid_part_tab_ext',
credential_name => 'obj_store_cred',
format => json_object('type' value 'csv', 'skipheaders' value '1'),
column_list => 'country_code varchar2(3),
object_id number,
owner varchar2(128),
object_name varchar2(128)',
partitioning_clause => 'partition by list (country_code) (
partition part_gbr values (''GBR'') external location (
''https://swiftobjectstorage.uk-london-1.oraclecloud.com/v1/my-namespace/ob-bucket/gbr1.txt'',
''https://swiftobjectstorage.uk-london-1.oraclecloud.com/v1/my-namespace/ob-bucket/gbr2.txt''
),
partition part_ire values (''IRE'') external location (
''https://swiftobjectstorage.uk-london-1.oraclecloud.com/v1/my-namespace/ob-bucket/ire1.txt'',
''https://swiftobjectstorage.uk-london-1.oraclecloud.com/v1/my-namespace/ob-bucket/ire2.txt''
),
partition part_usa values (''USA'')
)'
);
end;
/
We insert a row into the regular partition.
insert into country_hybrid_part_tab_ext values ('USA', 123, 'banana', 'banana');
commit;
We query the external table, which reads the data from the cloud object store.
select country_code, count(*) as amount
from country_hybrid_part_tab_ext
group by country_code
order by country_code;
COU AMOUNT
--- ----------
GBR 2000
IRE 2000
USA 1
SQL>
The VALIDATE_HYBRID_PART_TABLE procedure allows us to check the validity of an external hybrid partitioned table.
begin
dbms_cloud.validate_hybrid_part_table('country_hybrid_part_tab_ext');
end;
/
◉ Copy Data
The COPY_DATA procedure allows us to copy data from a cloud object store into an existing table.
We create a file called "emp.csv" with the following contents and place it into our object store. It is a CSV file with a header row.
"EMPNO","ENAME","JOB","MGR","HIREDATE","SAL","COMM","DEPTNO"
7369,"SMITH","CLERK",7902,17-DEC-80,800,,20
7499,"ALLEN","SALESMAN",7698,20-FEB-81,1600,300,30
7521,"WARD","SALESMAN",7698,22-FEB-81,1250,500,30
7566,"JONES","MANAGER",7839,02-APR-81,2975,,20
7654,"MARTIN","SALESMAN",7698,28-SEP-81,1250,1400,30
7698,"BLAKE","MANAGER",7839,01-MAY-81,2850,,30
7782,"CLARK","MANAGER",7839,09-JUN-81,2450,,10
7788,"SCOTT","ANALYST",7566,19-APR-87,3000,,20
7839,"KING","PRESIDENT",,17-NOV-81,5000,,10
7844,"TURNER","SALESMAN",7698,08-SEP-81,1500,0,30
7876,"ADAMS","CLERK",7788,23-MAY-87,1100,,20
7900,"JAMES","CLERK",7698,03-DEC-81,950,,30
7902,"FORD","ANALYST",7566,03-DEC-81,3000,,20
7934,"MILLER","CLERK",7782,23-JAN-82,1300,,10
We truncate the local EMP table and reload the data from the cloud object store using the COPY_DATA procedure.
truncate table emp;
begin
dbms_cloud.copy_data(
table_name => 'emp',
credential_name => 'obj_store_cred',
file_uri_list => 'https://swiftobjectstorage.uk-london-1.oraclecloud.com/v1/my-namespace/ob-bucket/emp.csv',
format => json_object('type' value 'csv', 'skipheaders' value '1')
);
end;
/
We query the EMP table, and we can see the data has been loaded.
select * from emp;
EMPNO ENAME JOB MGR HIREDATE SAL COMM DEPTNO
---------- ---------- --------- ---------- --------- ---------- ---------- ----------
7369 SMITH CLERK 7902 17-DEC-80 800 20
7499 ALLEN SALESMAN 7698 20-FEB-81 1600 300 30
7521 WARD SALESMAN 7698 22-FEB-81 1250 500 30
7566 JONES MANAGER 7839 02-APR-81 2975 20
7654 MARTIN SALESMAN 7698 28-SEP-81 1250 1400 30
7698 BLAKE MANAGER 7839 01-MAY-81 2850 30
7782 CLARK MANAGER 7839 09-JUN-81 2450 10
7788 SCOTT ANALYST 7566 19-APR-87 3000 20
7839 KING PRESIDENT 17-NOV-81 5000 10
7844 TURNER SALESMAN 7698 08-SEP-81 1500 0 30
7876 ADAMS CLERK 7788 23-MAY-87 1100 20
7900 JAMES CLERK 7698 03-DEC-81 950 30
7902 FORD ANALYST 7566 03-DEC-81 3000 20
7934 MILLER CLERK 7782 23-JAN-82 1300 10
14 rows selected.
SQL>
Similar to the external table examples, the FORMAT parameter allows us to tailor the load process to to suit the data file contents.
◉ Export Data
The EXPORT_DATA procedure takes the data generated by a query and exports it to a cloud object store in the requested format. This doesn't seem to work on the on-prem version of the DBMS_CLOUD package, but does work on Autonomous Database.
begin
dbms_cloud.export_data (
credential_name => 'obj_store_cred',
file_uri_list => 'https://swiftobjectstorage.uk-london-1.oraclecloud.com/v1/my-namespace/ob-bucket/emp.json',
query => 'select * from emp',
format => '{"type" : "JSON"}'
);
end;
/
begin
dbms_cloud.export_data (
credential_name => 'obj_store_cred',
file_uri_list => 'https://swiftobjectstorage.uk-london-1.oraclecloud.com/v1/my-namespace/ob-bucket/emp.csv',
query => 'select * from emp',
format => '{"type" : "CSV"}'
);
end;
/
◉ SODA Collections
Oracle databases can be used as a document store using Simple Oracle Document Access (SODA). You can read about SODA here.
We create a new collection called "TestCollection1".
set serveroutput on
declare
l_collection soda_collection_t;
begin
l_collection := dbms_soda.create_collection('TestCollection1');
if l_collection is not null then
dbms_output.put_line('Collection ID : ' || l_collection.get_name());
else
dbms_output.put_line('Collection does not exist.');
end if;
end;
/
Collection ID : TestCollection1
PL/SQL procedure successfully completed.
SQL>
Create a file called "fruit.json" with the following contents and upload it to your cloud object store.
{"fruit": "banana"}
The COPY_COLLECTION procedure loads the data from our cloud object store into the collection.
begin
dbms_cloud.copy_collection(
collection_name => 'TestCollection1',
credential_name => 'obj_store_cred',
file_uri_list => 'https://swiftobjectstorage.uk-london-1.oraclecloud.com/v1/my-namespace/ob-bucket/fruit.json',
format => json_object('unpackarrays' value 'true')
);
end;
/
We can see the data in the collection using the following query.
select json_document
from "TestCollection1";
JSON_DOCUMENT
--------------------------------------------------------------------------------
{"fruit":"banana"}
SQL>
◉ Delete Operations
Many of the DBMS_CLOUD operations produce additional files (log files, bad files, temp files etc.). These need to be cleaned up once an operation is complete. Several of the procedures shown above have overloads that return an operation ID value, which can be used with the DELETE_OPERATION procedure to clean up the extra files. Alternatively the operations for the current session can be displayed using the USER_LOAD_OPERATIONS view.
SQL> desc user_load_operations
Name Null? Type
----------------------------------------------------- -------- ------------------------------------
ID NOT NULL NUMBER
TYPE NOT NULL VARCHAR2(128)
SID NOT NULL NUMBER
SERIAL# NOT NULL NUMBER
START_TIME TIMESTAMP(6) WITH TIME ZONE
UPDATE_TIME TIMESTAMP(6) WITH TIME ZONE
STATUS VARCHAR2(9)
OWNER_NAME VARCHAR2(128)
TABLE_NAME VARCHAR2(128)
PARTITION_NAME VARCHAR2(128)
SUBPARTITION_NAME VARCHAR2(128)
FILE_URI_LIST VARCHAR2(4000)
ROWS_LOADED NUMBER
LOGFILE_TABLE VARCHAR2(128)
BADFILE_TABLE VARCHAR2(128)
TEMPEXT_TABLE VARCHAR2(128)
SQL>
We return the operations for the current session using the USER_LOAD_OPERATIONS view.
column type format a10
select id, type
from user_load_operations
order by 1;
ID TYPE
---------- ----------
1 COPY
11 COPY
SQL>
The DELETE_OPERATION procedure allows us to clear up the additional files associated with a specific operation.
begin
dbms_cloud.delete_operation(1);
end;
/
select id, type
from user_load_operations
order by 1;
ID TYPE
---------- ----------
11 COPY
SQL>
The DELETE_ALL_OPERATIONS procedure allows us to clean up the additional files for all operations, or those for specific types of operations if we specify the type value.
-- Delete only COPY operations.
begin
dbms_cloud.delete_all_operations('COPY');
end;
/
-- Delete all operations.
begin
dbms_cloud.delete_all_operations;
end;
/
Source: oracle-base.com
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