Husnu Sensoy

Sometimes moving a small amount of data in Oracle database requires more work than the actual task you need to complete. DBAs always have their tools (PL/SQL Developer Text Importer is my favorite one) to move a small amount of data between databases.
But when it comes to nested tables this might be a bit challenging. USER_SDO_GEOM_METADATA table (for those of you who are not familiar with it, it is the catalog information of spatial layers in an Oracle database) has no exception to that. Here how it is easy to handle it
The structure of USER_SDO_GEOM_METADATA table has the following structure

SQL> desc user_sdo_geom_metadata
 Name					   Null?    Type
 ----------------------------------------- -------- ----------------------------
 TABLE_NAME				   NOT NULL VARCHAR2(32)
 COLUMN_NAME				   NOT NULL VARCHAR2(1024)
 DIMINFO					    MDSYS.SDO_DIM_ARRAY
 SRID						    NUMBER

Obviously DIMINFO column is the problematic part since it is in SDO_DIM_ARRAY type. Now create a temporary table by unfolding this nested table at the source database site.

CREATE TABLE temp_metadata AS 
  SELECT t.table_name, 
         t.column_name, 
         d.*, 
         t.srid 
  FROM   user_sdo_geom_metadata t, 
         TABLE(t.diminfo) d; 

Once you are done check the structure of temp_metadata table which only contains primitive SQL types for the columns

SQL> desc temp_metadata
 Name					   Null?    Type
 ----------------------------------------- -------- ----------------------------
 TABLE_NAME					    VARCHAR2(32)
 COLUMN_NAME					    VARCHAR2(1024)
 SDO_DIMNAME					    VARCHAR2(64)
 SDO_LB 					    NUMBER
 SDO_UB 					    NUMBER
 SDO_TOLERANCE					    NUMBER
 SRID						    NUMBER

Choose your favorite tool to move this table to the target database since it contains just a few rows. Then as the final step import this data into USER_SDO_GEOM_METADATA table at the target database (Ensure that there is no other record with the same table_name.column_name key on the target USER_SDO_GEOM_METADATA table otherwise trigger on it will warn you)

insert into user_sdo_geom_metadata
SELECT m.table_name, m.column_name,
   CAST(MULTISET(SELECT sdo_dimname,sdo_lb,SDO_UB,sdo_tolerance
                 FROM temp_metadata n
                 WHERE n.table_name = m.table_name and n.column_name = m.column_name)
   AS SDO_DIM_ARRAY) as diminfo,
   m.srid
FROM (select distinct table_name,column_name,srid from temp_metadata) m;
commit;

You are done! Check everything works fine at the application site.

As you all may know, ASMLib is a recommended module for Oracle databases running on Linux platforms and it is an embedded module for UEK (Oracle Unbreakable Kernel) users. Oracle announced that (two years ago or so) they will no longer maintain ASMLib for Red Hat compatible kernel but this does not mean that they abandon the project, rather it is mainly related to the effort they need to put in maintaining the module for multiple kernel versions.

A while ago, Oracle added a new feature to ASMLib allowing ASM devices to choose between physical or logical block sizes in I/O operations. This should be, I believe, a fail-back mechanism for SSD devices used as ASM disks. Many SSD devices use 4K block size however Linux still uses default 512 bytes logical block size for those devices in the same way it does for motor disks. In early releases of ASMLib (oracleasm-support-2.1.7 and earlier), ASM uses physical block size (4K for SSDs). This is still the default behavior in oracleasm-support-2.1.8 but now sysadmin can choose between physical and logical blocksize by using [-b|-p] switches in oracleasm-configure.sh script.

• -b|—logical-blocks sets logical blocksize usage
• -p|—physical-blocks set physical blocksize usage

Those switches set /sys/module/oracleasm/parameters/use_logical_block_size which is default to be false (use physical blocksize). So that asmlib module can use the value to decide which block size to use.

I have upgraded one of my Oracle Linux boxes to Oracle Linux Release 5.9 which introduces several new things (Release Notes). Just to mention three of them

• java-1.7.0-openjdk
• firefox 10 (Although we have discuss to install latest version of it in Oracle Enterprise Linux for Home User: Install Latest Firefox Version )
• uek2 vanilla kernel branched from Linux Kernel Release 3.0.36
  • BTRFS
  • Transparent Huge Pages

Download and update yum repository file

[root@localhost yum.repos.d]$ cd /etc/yum.repos.d
[root@localhost yum.repos.d]$ wget http://public-yum.oracle.com/public-yum-el5.repo
[root@localhost yum.repos.d]$ mv public-yum-el5.repo.1 public-yum-el5.repo
[root@localhost yum.repos.d]$ grep -B 5 enabled=1 public-yum-el5.repo
[el5_latest]
name=Oracle Linux $releasever Latest ($basearch)
baseurl=http://public-yum.oracle.com/repo/OracleLinux/OL5/latest/$basearch/
gpgkey=http://public-yum.oracle.com/RPM-GPG-KEY-oracle-el5
gpgcheck=1
enabled=1
--
[ol5_u9_base]
name=Oracle Linux $releasever Update 9 installation media copy ($basearch)
baseurl=http://public-yum.oracle.com/repo/OracleLinux/OL5/9/base/$basearch/
gpgkey=http://public-yum.oracle.com/RPM-GPG-KEY-oracle-el5
gpgcheck=1
enabled=1
--
[ol5_UEK_latest]
name=Latest Unbreakable Enterprise Kernel for Oracle Linux $releasever ($basearch)
baseurl=http://public-yum.oracle.com/repo/OracleLinux/OL5/UEK/latest/$basearch/
gpgkey=http://public-yum.oracle.com/RPM-GPG-KEY-oracle-el5
gpgcheck=1
enabled=1

We are ready to upgrade

[root@localhost yum.repos.d]$ yum update

Rebounce Linux

[root@localhost yum.repos.d]$ reboot

Check Oracle Linux Version

[oracle@localhost ~]$ cat /etc/oracle-release
Oracle Linux Server release 5.8

Check kernel version

[oracle@localhost ~]$ uname -a
Linux localhost.localdomain 2.6.32-300.32.2.el5uek #1 SMP Tue Aug 28 10:15:29 EDT 2012 x86_64 x86_64 x86_64 GNU/Linux

Check your memory page size

[oracle@localhost ~]$ getconf PAGESIZE
4096

Once you are done after reboot, check Oracle Linux Version

[oracle@localhost ~]$ cat /etc/oracle-release
Oracle Linux Server release 5.9

Check kernel version

[oracle@localhost ~]$ uname -a
Linux localhost.localdomain 2.6.39-300.28.1.el5uek #1 SMP Tue Feb 5 10:15:29 PST 2013 x86_64 x86_64 x86_64 GNU/Linux

Check your memory page size

[oracle@localhost ~]$ getconf PAGESIZE
4096

Ooops!!! No change ?

[root@localhost ~]$ cat /sys/kernel/mm/transparent_hugepage/enabled 
[always] madvise never

Actually transparent huge page allocation is enabled but it deserves a separate discussion

Login database using

sqlplus / as sysdba

Dump the pfile using existing spfile

SQL> create pfile='/home/oracle/Desktop/init.ora' from spfile;

File created.

Oracle will generate implicit parameters defining current sizing of the memory regions in SGA and write them at the top of generated pfile

orcl.__db_cache_size=79691776
orcl.__java_pool_size=4194304
orcl.__large_pool_size=4194304
orcl.__oracle_base='/u01/app/oracle'#ORACLE_BASE set from environment
orcl.__pga_aggregate_target=142606336
orcl.__sga_target=272629760
orcl.__shared_io_pool_size=0
orcl.__shared_pool_size=167772160
orcl.__streams_pool_size=4194304
.
.
.
*.memory_target=414187520
.
.
.

Edit the file to disable AMM and enable static SGA configuration by simply removing memory_target, oracle_base and shared_io_pool_size parameters and doing some make up

*.db_cache_size=79691776
*.java_pool_size=4194304
*.large_pool_size=4194304
*.pga_aggregate_target=142606336
*.sga_target=272629760
*.shared_pool_size=167772160
*.streams_pool_size=4194304
.
.
.

Rebounce database instance by using modified pfile.

SQL> shutdown immediate;
Database closed.
Database dismounted.
ORACLE instance shut down.

SQL> startup pfile='/home/oracle/Desktop/init.ora';
ORACLE instance started.

Total System Global Area  271400960 bytes
Fixed Size                  2227544 bytes
Variable Size             180355752 bytes
Database Buffers           83886080 bytes
Redo Buffers                4931584 bytes
Database mounted.
Database opened.

Once you ensure that new pfile works, recreate new spfile using this pfile (refer to How to move ASM spfile to a different disk group [ID 1082943.1] if your target is ASM diskgroup)

SQL> create spfile using pfile='/home/oracle/Desktop/init.ora';

File created.

Finally rebounce the database by using new spfile

SQL> startup force;
ORACLE instance started.

Total System Global Area  271400960 bytes
Fixed Size                  2227544 bytes
Variable Size             180355752 bytes
Database Buffers           83886080 bytes
Redo Buffers                4931584 bytes
Database mounted.
Database opened.

I have announced my webinar on Oracle ZFS Storage Appliance for Exadata Backup & Recovery in NYOUG DBA webinar series. You can download webinar slides and voice recod from NYOUG web site