Utility Belt

Indexes

Rebuild all indexes of a Partitioned Table

“Holy rebuilding work, DBAtman!”
Cool, we have that scripted in my Utility Belt!

If you frequently need to collect all indexes of a partioned table (local and global indexes), this is a quick script that make the task a little bit easier:

begin
-- local indexes
for i in (select p.index_owner owner, p.index_name, p.partition_name
from dba_indexes i, dba_ind_partitions p
where i.owner='&OWNER'
and   i.table_name='&TABLE'
and   i.partitioned='YES'
and   i.visibility='VISIBLE' -- Rebuild only of the visible indexes, to get real effect :)
and   p.index_name=i.index_name
and   p.index_owner=i.owner
order by 1,2) loop
execute immediate 'alter index '||i.owner||'.'||i.index_name||' rebuild  partition '||i.partition_name||' online parallel 12'; -- parallel 12 solve most of the problems
execute immediate 'alter index '||i.owner||'.'||i.index_name||' parallel 1'; -- If you don't use parallel indexes in your database, or the default parallel of the index, or what you want...
end loop;
-- global indexes
for i in (select i.owner owner, i.index_name
from dba_indexes i
where i.owner='&OWNER'
and   i.table_name='&TABLE'
and   i.partitioned='NO'
and   i.visibility='VISIBLE' -- same comment
order by 1,2) loop
execute immediate 'alter index '||i.owner||'.'||i.index_name||' rebuild online parallel 12'; -- same
execute immediate 'alter index '||i.owner||'.'||i.index_name||' parallel 1'; -- same :)
end loop;
end;
/

Na, na, na, na, na, na, na, na, na, na, na, na… DBAtman!

Database, Statistics

Oracle TPS: Evaluating Transaction per Second

“Holy ‘My Boss wants Oracle TPS metrics’, DBAtman!”
Don’t worry young Robin, we can get it for you…

Sometimes this information has some ‘myth atmosphere’… Maybe because of that Oracle doesn’t have this information that clear and it’s not the most useful metric.
But for comparison to another systems and also to performance/’throughput’ with different infrastructure/database configuration, it can be useful.

It can be seen by AWR on “Report Summary” section, on “Load Profile”, “Transactions” item:

awr_tps

But if you want to calculate it through SQL query?
And if you want to have a historic from this metric?

I found a reference for this calculation here, using v$sysstat.
It’s the only reference I found, and it on 10g documentation… It refers this metric as:

Number of Transactions = (DeltaCommits+DeltaRollbacks)/Time

It also refers as DeltaCommits and DeltaRollbacks, respectively, “user commits” and user “rollbacks”.

Where it goes a possible SQL to do that:

WITH hist_snaps
AS (SELECT instance_number,
snap_id,
round(begin_interval_time,'MI') datetime,
(  begin_interval_time + 0 - LAG (begin_interval_time + 0)
OVER (PARTITION BY dbid, instance_number ORDER BY snap_id)) * 86400 diff_time
FROM dba_hist_snapshot), hist_stats
AS (SELECT dbid,
instance_number,
snap_id,
stat_name,
VALUE - LAG (VALUE) OVER (PARTITION BY dbid,instance_number,stat_name ORDER BY snap_id)
delta_value
FROM dba_hist_sysstat
WHERE stat_name IN ('user commits', 'user rollbacks'))
SELECT datetime,
ROUND (SUM (delta_value) / 3600, 2) "Transactions/s"
FROM hist_snaps sn, hist_stats st
WHERE     st.instance_number = sn.instance_number
AND st.snap_id = sn.snap_id
AND diff_time IS NOT NULL
GROUP BY datetime
ORDER BY 1 desc;

I like to use PL/SQL Developer to see this kind of data. And it regards us to make very good charts very quickly. I try it in a small database here, just for example:

7days_tps

Jedi Master Jonathan Lewis wrote a good post about Transactions and this kind of AWR metric here.

Na, na, na, na, na, na, na, na, na, na, na, na… DBAtman!

Database Link, Table

Copy Large Table Through DBLink

“Holy nothing works here, DBAtman!”
Take it easy, young Robin: DBAtman always has a solution…

To understand the situation:

Task: Need to migrate large database 11.1.0.6 to 12c Multi-Tenant Database with minimum downtime.
To better use the features, reorginize objects and compress data, I decided to migrate the data logically (not physically).
The first option was to migrate schema by schema through datapump with database link. There is no long columns.

Problem1: The database was veeery slow with perfect match to Bug 7722575 -DATAPUMP VIEW KU$_NTABLE_DATA_VIEW causes poor plan / slow Expdp.
workaround: None
Solution: Upgrade to 11.2. (No way).
Other things: Yes, I tried to change the cursor sharing, the estimate from blocks to statistics and all things documented. It doesn’t work.

Ok doke! Let’s use traditional exp/imp tools (with some migration area), right?
Problem2: ORA-12899 on import related to multiblocking x singleblocking charsets.
Solution: https://grepora.com/2015/11/20/charsets-single-byte-vs-multibyte-issue/
:)

Done? Not for all. For some tables, just happened the error:

EXP-00006: internal inconsistency error
EXP-00000: Export terminated unsuccessfully

An what Oracle says? “Solution: Use Datapump!”😛

Well, well… I realized I was going to become by myself…
Ok, so lets create table as select using database link. For most of all, ok…
But, for example, one of the missing tables has 700 million rows (350GB of compressed and no partitioned data).
Just to remmember that DBLink exclude parallel options (always serial).

The solution was to make a McGayver, this way:
1) Creating an aux table (source database):

alter session force parallel query parallel 12;
create table SCHEMA_OWNER.AUX_ROWID(ROW_ID,NUM) as select rowid, rownum from SCHEMA_OWNER.TABLE;
alter session disable parallel query;

* This table will be used to break the table in chunks.

2) Script run_chunck.sql to run each chunk of data:

DECLARE
counter number;
CURSOR cur_data is
select row_id from (
select row_id, num from SCHEMA_OWNER.AUX_ROWID@SOURCEDB order by num)
where num >= &1
and num <=&2;
BEGIN
counter :=0;
FOR x IN cur_data LOOP
BEGIN
counter := counter +1;
insert into SCHEMA_OWNER.TABLE select * from SCHEMA_OWNER.TABLE@SOURCEDB where rowid = x.row_id;
if counter = 1000 then ---commit every 1000 rows
commit;
counter := 0;
end if;
EXCEPTION
when OTHERS then
dbms_output.put_line('Error ROW_ID: '||x.row_id||sqlerrm);
END;
END LOOP;
COMMIT;
END;
/
exit;

3) Run in a BAT or SH like (my example was made for a bat, with “chunks” of 50 million rows – and commits by every 1k, defined on item 2):

@echo off
set /p db="Target Database.: "
set /p user="Username.......: "
set /p pass="Password..................: "
pause
START sqlplus %user%/%pass%@%db% @run_chunck.sql 1 2060053
START sqlplus %user%/%pass%@%db% @run_chunck.sql 2060054 52060053
START sqlplus %user%/%pass%@%db% @run_chunck.sql 52060054 102060053
START sqlplus %user%/%pass%@%db% @run_chunck.sql 102060054 152060053
START sqlplus %user%/%pass%@%db% @run_chunck.sql 152060054 202060053
START sqlplus %user%/%pass%@%db% @run_chunck.sql 202060054 252060053
START sqlplus %user%/%pass%@%db% @run_chunck.sql 252060054 302060053
START sqlplus %user%/%pass%@%db% @run_chunck.sql 302060054 352060053
START sqlplus %user%/%pass%@%db% @run_chunck.sql 352060054 402060053
START sqlplus %user%/%pass%@%db% @run_chunck.sql 402060054 452060053
START sqlplus %user%/%pass%@%db% @run_chunck.sql 452060054 502060053
START sqlplus %user%/%pass%@%db% @run_chunck.sql 502060054 552060053
START sqlplus %user%/%pass%@%db% @run_chunck.sql 552060054 602060053
START sqlplus %user%/%pass%@%db% @run_chunck.sql 602060054 652060053
START sqlplus %user%/%pass%@%db% @run_chunck.sql 652060054 702060053 -- count(*) from table

Watching the inserts running…

targetdb>@sess
User:DBATMAN_HELPS
USERNAME EVENT SQL_ID
---------- ---------- -------------------------
DBATMAN_HELPS SQL*Net message from dblink 6qc1hsnkkfhnw
DBATMAN_HELPS SQL*Net message from dblink 6qc1hsnkkfhnw
DBATMAN_HELPS SQL*Net message from dblink 6qc1hsnkkfhnw
DBATMAN_HELPS SQL*Net message from dblink 6qc1hsnkkfhnw
DBATMAN_HELPS SQL*Net message from dblink 6qc1hsnkkfhnw
DBATMAN_HELPS SQL*Net message from dblink 6qc1hsnkkfhnw
DBATMAN_HELPS SQL*Net message from dblink 6qc1hsnkkfhnw
DBATMAN_HELPS SQL*Net message from dblink gt3mq5ct7mt6r
DBATMAN_HELPS SQL*Net message from dblink 6qc1hsnkkfhnw
DBATMAN_HELPS SQL*Net message from dblink 6qc1hsnkkfhnw
DBATMAN_HELPS SQL*Net message from dblink 6qc1hsnkkfhnw
DBATMAN_HELPS SQL*Net message from dblink 6qc1hsnkkfhnw
DBATMAN_HELPS SQL*Net message from dblink 6qc1hsnkkfhnw
DBATMAN_HELPS SQL*Net message from dblink 6qc1hsnkkfhnw
DBATMAN_HELPS SQL*Net message from dblink 6qc1hsnkkfhnw
DBATMAN_HELPS SQL*Net message from client
DBATMAN_HELPS SQL*Net message from client
DBATMAN_HELPS SQL*Net message to client c7a5tcc3a84k6

After a few (26 hours) the copy was successfully concluded.:)

Na, na, na, na, na, na, na, na, na, na, na, na… DBAtman!

Lock

Lock by DBLink – Which is te session in the remote database?

“Holy Remote Session, DBAtman!”
Who is this in the remote DB?

Important, right? What if you identify a lock or other unwanted operation by a DBLink session, how to identify the original session in remote database (origin dabatase)?
The one million answer is simple: by process of v$session. By the way, looks like is easier than find the local process (spid)… Take a look in my example (scripts in the end of post):

dest> @sid
Sid:10035
Inst:1
SEQ# EVENT MODULE STATUS SID SERIAL# INST_ID
----- --------- ---------- ---------- ---------- ---------- ----------
29912 SQL*Net message from client oracle@origin2(TNS V1-V3) INACTIVE 10035 35 1
dest> @spid
SPID SID PID PROCESS_FOR_DB_LINK MACHINE LOGON_TIME
------ ---------- ---------- ----------- ----------- -----------
16188960 10035 882 17302472 origin2 24/08/2015 07:43:40

Now I know the sid 10035 refers to local process 16188960 and the process on origin database is 17302472. What I do what I want if this process:

root@origin2:/oracle/diag/rdbms/origin/origin2/trace>ps -ef |grep 17302472
grid 17302472 1 97 07:42:42 - 5:58 oracleorigin2 (LOCAL=NO)
root 24445782 36700580 0 08:05:45 pts/3 0:00 grep 17302472

What include to locae the session in the database by spid, see the sql, and etecetera:

origin> @spid2
Enter value for process: 17302472
SID SERIAL# USERNAME OSUSER PROGRAM STATUS
------- ---------- ----------- ----------- --------------- ----------
7951 41323 USER_XPTO scheduler_user sqlplus@scheduler_app.domain.net (TNS V1-V3) ACTIVE
database2> @sid
Sid:7951
Inst: 2
SQL_ID SEQ# EVENT MODULE STATUS SID SERIAL# INST_ID
---------- ----- --------- ------- --------- ----- ------ ----------
1w1wz2mdunya1 56778 db file sequential read REMOTE_LOAD ACTIVE 7951 41323 2

That’s OK?
Simple isn’t?

The used Scripts (except the “sid”, that is a simple SQL on gv$session):

Get SPID and PROCESS FOR DBLINK from a SID:

# spid:
col machine format a30
col process format 999999
select p.spid,b.sid, p.pid, b.process as process_for_db_link, machine, logon_time
from v$session b, v$process p
where b.paddr=p.addr
and sid=&sid
/

Get SID from SPID:

#spid2:
SELECT s.sid, s.serial#, s.username,
s.osuser, s.program, s.status,
FROM v$session s, v$process p
WHERE s.paddr = p.addr
AND p.spid IN (&process);
/

Na, na, na, na, na, na, na, na, na, na, na, na… DBAtman!

SQPlus

Sqlplus: Connect without configure TNSNAMES

“Holy easy stuff, DBAtman!”

Okey, you must to know, but is always useful to remember that… If you don’t want to configure your TNSNAMES, you can connect directly to description of your database.

You can do it in two ways: First one is using Easy Connect. But some tools simply don’t support it. Here is the second way, just like using TNSNAMES but without TNSNAMES:

sqlplus> conn matheus_boesing@(DESCRIPTION=(ADDRESS_LIST=(ADDRESS=(PROTOCOL=TCP)(HOST=mydb.domain.net)(PORT=1521)))(CONNECT_DATA=(service_name=mydb)))
Enter password: ********
Connected.
sqlplus>

Based on this, I made two scripts, to connect with the sid (c.sql) or with the service_name (s.sql) and make my life easier. Here the scripts:

sqlplus>get c
1 DEFINE VHOST = &1.
2 DEFINE VPORT = &2.
3 DEFINE VSID = &3.
4 DEFINE VDESC='(DESCRIPTION=(ADDRESS_LIST=(ADDRESS=(PROTOCOL=TCP)(HOST=&VHOST)(PORT=&VPORT)))(CONNECT_DATA=(SID=&VSID)(server=dedicated)))'
5 disconnect
6 connect dbatman@&&VDESC
7 set linesize 1000
8 set sqlprom '&&VSID> '
9 select instance_name, host_name
10 from v$instance;
11 exec dbms_application_info.SET_MODULE('MATHEUS_BOESING','DBA');
12 alter session set nls_date_format='DD/MM/YYYY HH24:MI:SS';
13 UNDEFINE VDESC
14 UNDEFINE 1
15 UNDEFINE 2
16* UNDEFINE 3
sqlplus>get s
1 DEFINE VHOST = &1.
2 DEFINE VPORT = &2.
3 DEFINE VSID = &3.
4 DEFINE VDESC='(DESCRIPTION=(ADDRESS_LIST=(ADDRESS=(PROTOCOL=TCP)(HOST=&VHOST)(PORT=&VPORT)))(CONNECT_DATA=(SERVICE_NAME=&VSID)(server=dedicated)))'
5 prompt &VDESC
6 disconnect
7 connect dbatman@&&VDESC
8 set linesize 1000
9 set sqlprom '&&VSID> '
10 select instance_name, host_name
11 from v$instance;
12 exec dbms_application_info.SET_MODULE('MATHEUS_BOESING','DBA');
13 alter session set nls_date_format='DD/MM/YYYY HH24:MI:SS';
14 UNDEFINE VDESC
15 UNDEFINE 1
16 UNDEFINE 2
17* UNDEFINE 3
sqlplus>

It can be used like this:

sqlplus>@s mydb.domain.net 1521 mydb
(DESCRIPTION=(ADDRESS_LIST=(ADDRESS=(PROTOCOL=TCP)(HOST=mydb.domain.net)(PORT=1521)))(CONNECT_DATA=(SERVICE_NAME=mydb)(server=dedicated)))
Enter password: ********
Connected.

Ok, but, let’s suppose you are working in a cluster and wants to connect directly to the another instance. I made the script below (ci.sql). It’s not beautiful, but is a lot hopeful:

sqlplus> get ci
1 DEFINE VINT = &1.
2 undefine VHOST
3 undefine VSID
4 VARIABLE VCONN varchar2(100)
5 PRINT ret_val
6 BEGIN
7 SELECT '@c '||host_name||' 1521 '||INSTANCE_NAME
8 INTO :VCONN
9 FROM gv$instance where INSTANCE_NUMBER=&VINT;
10 END;
11 /
12 set head off;
13 spool auxcon.sql
14 prompt set head on;
15 print :VCONN
16 prompt set head on;
17 spool off;
18* @auxcon
sqlplus>

As you see, you inform the inst_id you want to connect. It can be used like:

mydb> @instance
INSTANCE_NAME
------------------------------
mydb_2
mydb> @instances
INST_NUMBER INST_NAME
----------- ---------------------------------------
1 db2srvr2p.grepora.net:mydb_1
2 db1srvr1p.grepora.net:mydb_2
mydb> @ci 1
@c db2srvr2p.grepora.net 1521 mydb_1
Disconnected from Oracle Database 11g Enterprise Edition Release 11.2.0.1.0 - 64bit Production
With the Partitioning, Real Application Clusters, Automatic Storage Management, OLAP,
Data Mining and Real Application Testing options
Enter password: ********
Connected.
mydb_1> @instance
INSTANCE_NAME
------------------------------
mydb_1

Na, na, na, na, na, na, na, na, na, na, na, na… DBAtman!

ASM

ASM: Disk Size Imbalance Query

“Holy Imbalance, DBAtman!”
Is that right?

It can be useful if you work frequently with OEM metrics…

# OEM’s 12c Query

SELECT file_num, MAX(extent_count) max_disk_extents, MIN(extent_count)
min_disk_extents
, MAX(extent_count) - MIN(extent_count) disk_extents_imbalance
FROM (SELECT number_kffxp file_num, disk_kffxp disk_num, COUNT(xnum_kffxp)
extent_count
FROM x$kffxp
WHERE group_kffxp = 1
AND disk_kffxp != 65534
GROUP BY number_kffxp, disk_kffxp
ORDER BY number_kffxp, disk_kffxp)
GROUP BY file_num
HAVING MAX(extent_count) - MIN(extent_count) > 5
ORDER BY disk_extents_imbalance DESC;

# DBAtman’s Query

select max(free_mb) biggest, min(free_mb) lowest, avg(free_mb) AVG,
trunc(GREATEST ((avg(free_mb)*100/max(free_mb)),(min(free_mb)*100/avg(free_mb))),2)||'%' as balanced,
trunc(100-(GREATEST ((avg(free_mb)*100/max(free_mb)),(min(free_mb)*100/avg(free_mb)))),2)||'%' as inbalanced
from v$asm_disk
where group_number in
(select group_number from v$asm_diskgroup where name = upper('&DG'));

I made my own query for two reasons:
1) I didn’t have the OEM query in the time i made it.
2) My query measures the imbalance with the avg of the disks (if every disk would balanced, how would be the difference), rather than the real/present difference between the disk with the maximum and the minimum usage…

So, you can chose the one you need… 🙂

Na, na, na, na, na, na, na, na, na, na, na, na… DBAtman!