Sunday, October 7, 2018

How to list all schemas and their sizes


If you want a list of schema sizes, join dba_segments with dba_users to limit the extract to users that are non-oracle maintained:
set lines 200
col owner  format a30
col "GB" format 999999
SELECT s.owner,sum(s.bytes/1024/1024/1024) "GB"
FROM dba_segments s join dba_users u
on (s.owner = u.username)
where u.oracle_maintained = 'N'
group by owner
ORDER BY 2 desc;

Example output
OWNER                               GB
------------------------------ -------
USER1                            19577
USER2                             6144
USER3                             2306

Friday, September 28, 2018

How to work around ORA-38338: incorrect ILM policy scope for row-level ADO policies


When adding an ADO policy on a table, like this:

CREATE TABLE TEST_TABLE1
(
  col1 NUMBER(38),
  col2 NUMBER(38),
  col3 DATE
)
NOCOMPRESS 
TABLESPACE USERS
ILM ADD POLICY ROW STORE COMPRESS ADVANCED 
ROW AFTER 1 DAY OF NO ACCESS;

oracle returned


ORA-38338: incorrect ILM policy scope

This policy is not valid for row-level ADO policy. The only valid option is

ILM ADD POLICY ROW STORE COMPRESS ADVANCED 
ROW AFTER X DAY OF NO MODIFICATION;

Monday, September 24, 2018

How to deinstall an old oracle installation using oui

You can use the following command to remove an obsolete oracle software installation from the central inventory:
$ORACLE_HOME/oui/bin/runInstaller -silent -deinstall REMOVE_HOMES={"/u01/oracle/product/11204"}

Remember to clean out the physical files with an appropriate operating system command.

The above method is an alternative to the method outlined in this post.

Friday, September 21, 2018

Parameters that can be removed after upgrade to 12.2

From Information For Parameters _upgrade_optim and _upgrade_capture_noops (Doc ID 2182783.1):


Below parameters gets added after upgrade to 12.2:

_upgrade_optim = FALSE
_upgrade_capture_noops = FALSE

These parameters are part of upgrade optimizations. They do not have any effect on upgrade currently.

Since these parameters does not have any impact, it can be removed safely after upgrade to 12.2.


Can be removed, like this:
echo "alter system reset \"_upgrade_optim\" scope=spfile SID='*';" | sqlplus / as sysdba
echo "alter system reset \"_upgrade_capture_noops\" scope=spfile SID='*';" | sqlplus / as sysdba

Thursday, September 20, 2018

How to load a plan from the AWR into the SMB


To load a plan found in an AWR snapshot into the SMB, you need to add it to an STS first, then load it into the SMB.
Here is how:

1. create an empty STS:
exec dbms_sqltune.create_sqlset(sqlset_name=>'mysts');

2. Note the snapshots where your plan was recorded, and add the plans to your STS:
DECLARE
  my_cur  dbms_sqltune.sqlset_cursor;
BEGIN
  OPEN my_cur FOR
     SELECT VALUE(x)
     FROM   TABLE( dbms_sqltune.select_workload_repository(begin_snap=>5840, 
                                                           end_snap=>5841, 
                                                           basic_filter=>'sql_id = ''45wmakdh9ak9s''')) x;

     dbms_sqltune.load_sqlset(sqlset_name => 'mysts', populate_cursor => my_cur);
END;
/

You can now check your STS for its contents:
select sqlset_name,
     sql_id,
     plan_timestamp,
     parsing_schema_name "schema",
     plan_hash_value,round(elapsed_time/1000000) "duration in seconds",
     cpu_time,
     buffer_gets,
     disk_reads,
     executions
from   dba_sqlset_statements
where  sqlset_name = 'mysts'
;

SQLSET_NAME SQL_ID PLAN_TIMESTAMP schema PLAN_HASH_VALUE duration in seconds CPU_TIME BUFFER_GETS DISK_READS EXECUTIONS
mysts 45wmakdh9ak9s 11.09.2018 15:22:13 SH
3827183161
0
0
0
0
0
mysts 45wmakdh9ak9s 06.09.2018 16:45:26 SH
4026264003
579
85550842
24062750
101808
3278857

We can see from the output that there are actually two different plans in the STS now, one with plan_hash_value=3827183161 and another one with plan_hash_value=4026264003.

In my case I wanted only the one with plan_hash_value=3827183161.

3. Finallly, load the contents of your STS into your SMB:
VARIABLE cnt NUMBER
EXECUTE :cnt := DBMS_SPM.LOAD_PLANS_FROM_SQLSET( -
                    sqlset_name=>'mysts', basic_filter=>'plan_hash_value=3827183161', sqlset_owner=>'SYS');

print :cnt;

How to drop an STS


exec dbms_sqltune.drop_sqlset ('mysts');

Yet another example on how to create and populate an STS


Here is how to create an STS and populate it with SQL statements matching a particular SQL ID:
exec dbms_sqltune.create_sqlset(sqlset_name=>'mysts');

DECLARE
  my_cur  dbms_sqltune.sqlset_cursor;
BEGIN
  OPEN my_cur FOR
     SELECT VALUE(x)
     FROM   TABLE( dbms_sqltune.select_cursor_cache(basic_filter=>'sql_id = ''45wmakdh9ak9s''')) x;

     dbms_sqltune.load_sqlset(sqlset_name => 'mysts', populate_cursor => my_cur);
END;
/

Check the contents of the STS:
set lines 200

col name format a20
col owner format a20
col created format a30
col statement_count format 999999999999
select name,owner,created,statement_count
from dba_sqlset
where name = 'mysts';

And check the details of the statements packed in the STS, like this:
select sql_id,plan_timestamp,parsing_schema_name,plan_hash_value,round(elapsed_time/1000000) "duration in seconds",cpu_time,buffer_gets,disk_reads,executions
from   dba_sqlset_statements
where  sqlset_name = 'mysts'
fetch first 3 rows only;

SQL_ID PLAN_TIMESTAMP PARSING_SCHEMA_NAME PLAN_HASH_VALUE duration in seconds CPU_TIME BUFFER_GETS DISK_READS EXECUTIONS
45wmakdh9ak9s 18.09.2018 23:48:21 SCOTT
4026264003
7718
1331447472
336095417
828189
40286996