Tuesday, August 9, 2016

Some TEMP tablespace related queries and scripts



To check instance-wise total allocated, total used TEMP for both rac and non-rac

set lines 152
col FreeSpaceGB format 999.999
col UsedSpaceGB format 999.999
col TotalSpaceGB format 999.999
col host_name format a30
col tablespace_name format a30
select tablespace_name,
(free_blocks*8)/1024/1024 FreeSpaceGB,
(used_blocks*8)/1024/1024 UsedSpaceGB,
(total_blocks*8)/1024/1024 TotalSpaceGB,
i.instance_name,i.host_name
from gv$sort_segment ss,gv$instance i where ss.tablespace_name in (select tablespace_name from dba_tablespaces where contents='TEMPORARY') and
i.inst_id=ss.inst_id;

Total Used and Total Free Blocks

select inst_id, tablespace_name, total_blocks, used_blocks, free_blocks  from gv$sort_segment;

Another Query to check TEMP USAGE

col name for a20
SELECT d.status "Status", d.tablespace_name "Name", d.contents "Type", d.extent_management
"ExtManag",
TO_CHAR(NVL(a.bytes / 1024 / 1024, 0),'99,999,990.900') "Size (M)", TO_CHAR(NVL(t.bytes,
0)/1024/1024,'99999,999.999') ||'/'||TO_CHAR(NVL(a.bytes/1024/1024, 0),'99999,999.999') "Used (M)",
TO_CHAR(NVL(t.bytes / a.bytes * 100, 0), '990.00') "Used %"
FROM sys.dba_tablespaces d, (select tablespace_name, sum(bytes) bytes from dba_temp_files group by
tablespace_name) a,
(select tablespace_name, sum(bytes_cached) bytes from
v$temp_extent_pool group by tablespace_name) t
WHERE d.tablespace_name = a.tablespace_name(+) AND d.tablespace_name = t.tablespace_name(+)
AND d.extent_management like 'LOCAL' AND d.contents like 'TEMPORARY';

Temporary Tablespace groups

SELECT * FROM DATABASE_PROPERTIES where PROPERTY_NAME='DEFAULT_TEMP_TABLESPACE';

select tablespace_name,contents from dba_tablespaces where tablespace_name like '%TEMP%';

select * from dba_tablespace_groups;

Block wise Check

select TABLESPACE_NAME, TOTAL_BLOCKS, USED_BLOCKS, MAX_USED_BLOCKS, MAX_SORT_BLOCKS, FREE_BLOCKS from V$SORT_SEGMENT;

select sum(free_blocks) from gv$sort_segment where tablespace_name = 'TEMP';
To Check Percentage Usage of Temp Tablespace

select (s.tot_used_blocks/f.total_blocks)*100 as "percent used"
from (select sum(used_blocks) tot_used_blocks
from v$sort_segment where tablespace_name='TEMP') s,
(select sum(blocks) total_blocks
from dba_temp_files where tablespace_name='TEMP') f;

To check Used Extents ,Free Extents available in Temp Tablespace

SELECT tablespace_name, extent_size, total_extents, used_extents,free_extents, max_used_size FROM v$sort_segment;

To list all tempfiles of Temp Tablespace

col file_name for a45
select tablespace_name,file_name,bytes/1024/1024,maxbytes/1024/1024,autoextensible from dba_temp_files  order by file_name;

SELECT d.tablespace_name tablespace , d.file_name filename, d.file_id fl_id, d.bytes/1024/1024
size_m
, NVL(t.bytes_cached/1024/1024, 0) used_m, TRUNC((t.bytes_cached / d.bytes) * 100) pct_used
FROM
sys.dba_temp_files d, v$temp_extent_pool t, v$tempfile v
WHERE (t.file_id (+)= d.file_id)
AND (d.file_id = v.file#);

Additional checks

select distinct(temporary_tablespace) from dba_users;

select username,default_tablespace,temporary_tablespace from dba_users order by temporary_tablespace;

SELECT * FROM DATABASE_PROPERTIES where PROPERTY_NAME='DEFAULT_TEMP_TABLESPACE';

Changing the default temporary Tablespace

SQL> alter database default temporary tablespace TEMP;

Database altered.

To add tempfile to Temp Tablespace

alter tablespace  temp  add tempfile '&tempfilepath' size 1800M;

alter tablespace temp add tempfile '/m001/oradata/SID/temp02.dbf' size 1000m;

alter tablespace TEMP add tempfile '/SID/oradata/data02/temp04.dbf' size 1800M autoextend on maxsize 1800M;

To resize the  tempfile in Temp Tablespace

alter database tempfile '/u02/oradata/TESTDB/temp01.dbf' resize 250M

alter database tempfile '/SID/oradata/data02/temp12.dbf' autoextend on maxsize 1800M;

alter tablespace TEMP add tempfile '/SID/oradata/data02/temp05.dbf' size 1800m reuse;

To find Sort Segment Usage by Users

select username,sum(extents) "Extents",sum(blocks) "Block"
from v$sort_usage
group by username;

To find Sort Segment Usage by a particular User

SELECT s.username,s.sid,s.serial#,u.tablespace, u.contents, u.extents, u.blocks
FROM v$session s, v$sort_usage u
WHERE s.saddr=u.session_addr
order by u.blocks desc;

To find Total Free space in Temp Tablespace

select 'FreeSpace  ' || (free_blocks*8)/1024/1024 ||' GB'  from v$sort_segment where tablespace_name='TEMP';

select tablespace_name , (free_blocks*8)/1024/1024  FreeSpaceInGB,
(used_blocks*8)/1024/1024  UsedSpaceInGB,
(total_blocks*8)/1024/1024  TotalSpaceInGB
from v$sort_segment where tablespace_name like '%TEMP%'

To find  Total Space Allocated for Temp Tablespace

select 'TotalSpace ' || (sum(blocks)*8)/1024/1024 ||' GB'  from dba_temp_files where tablespace_name='TEMP';

Get 10 sessions with largest temp usage

cursor bigtemp_sids is
select * from (
select s.sid,
s.status,
s.sql_hash_value sesshash,
u.SQLHASH sorthash,
s.username,
u.tablespace,
sum(u.blocks*p.value/1024/1024) mbused ,
sum(u.extents) noexts,
nvl(s.module,s.program) proginfo,
floor(last_call_et/3600)||':'||
floor(mod(last_call_et,3600)/60)||':'||
mod(mod(last_call_et,3600),60) lastcallet
from v$sort_usage u,
v$session s,
v$parameter p
where u.session_addr = s.saddr
and p.name = 'db_block_size'
group by s.sid,s.status,s.sql_hash_value,u.sqlhash,s.username,u.tablespace,
nvl(s.module,s.program),
floor(last_call_et/3600)||':'||
floor(mod(last_call_et,3600)/60)||':'||
mod(mod(last_call_et,3600),60)
order by 7 desc,3)
where rownum < 11;

Displays the amount of IO for each tempfile

SELECT SUBSTR(t.name,1,50) AS file_name,
f.phyblkrd AS blocks_read,
f.phyblkwrt AS blocks_written,
f.phyblkrd + f.phyblkwrt AS total_io
FROM   v$tempstat f,v$tempfile t
WHERE  t.file# = f.file#
ORDER BY f.phyblkrd + f.phyblkwrt DESC;

select * from (SELECT u.tablespace, s.username, s.sid, s.serial#, s.logon_time, program, u.extents, ((u.blocks*8)/1024) as MB,
i.inst_id,i.host_name
FROM gv$session s, gv$sort_usage u ,gv$instance i
WHERE s.saddr=u.session_addr and u.inst_id=i.inst_id  order by MB DESC) a where rownum<10;

Check for ORA-1652

show parameter background

cd <background dump destination>

ls -ltr|tail

view <alert log file name>

shift + G ---> to get the tail end...

?ORA-1652 ---- to search of the error...

shift + N ---- to step for next reported error...

I used these queries to check some settings:

-- List all database files and their tablespaces:
select  file_name, tablespace_name, status
,bytes   /1000000  as MB
,maxbytes/1000000  as MB_max
from dba_data_files ;

-- What temporary tablespace is each user using?:
select username, temporary_tablespace, default_tablespace from dba_users ;

-- List all tablespaces and some settings:
select tablespace_name, status, contents, extent_management
from dba_tablespaces ;

TABLESPACE_NAME                CONTENTS  EXTENT_MAN STATUS
------------------------------ --------- ---------- ---------
SYSTEM                         PERMANENT DICTIONARY ONLINE
TOOLS                          PERMANENT DICTIONARY ONLINE
TEMP                           TEMPORARY DICTIONARY OFFLINE
TMP                            TEMPORARY LOCAL      ONLINE

Now, the above query and the storage clause of the old 'create tablespace TEMP' command seem to tell us the tablespace only allows temporary objects, so it should be safe to assume that no one created any tables or other permanent objects in TEMP by mistake, as I think Oracle would prevent that. However, just to be absolutely certain, I decided to double-check. Checking for any tables in the tablespace is very easy:

-- Show number of tables in the TEMP tablespace - SHOULD be 0:
select count(*)  from dba_all_tables
where tablespace_name = 'TEMP' ;

Checking for any other objects (views, indexes, triggers, pl/sql, etc.) is trickier, but this query seems to work correctly - note that you'll probably need to connect internal in order to see the sys_objects view:

-- Shows all objects which exist in the TEMP tablespace - should get
-- NO rows for this:
column owner        format a20
column object_type  format a30
column object_name  format a40
select
o.owner  ,o.object_name
,o.object_type
from sys_objects s
,dba_objects o
,dba_data_files df
where df.file_id = s.header_file
and o.object_id = s.object_id
and df.tablespace_name = 'TEMP' ;

Identifying WHO is currently using TEMP Segments

10g onwards

SELECT sysdate,a.username, a.sid, a.serial#, a.osuser, (b.blocks*d.block_size)/1048576 MB_used, c.sql_text
FROM v$session a, v$tempseg_usage b, v$sqlarea c,
     (select block_size from dba_tablespaces where tablespace_name='TEMP') d
    WHERE b.tablespace = 'TEMP'
    and a.saddr = b.session_addr
    AND c.address= a.sql_address
    AND c.hash_value = a.sql_hash_value
    AND (b.blocks*d.block_size)/1048576 > 1024
    ORDER BY b.tablespace, 6 desc;

How-to find the SQL that using lots of temp tablespace in Oracle

How-to find the SQL that using lots of temp tablespace in Oracle



select b.Total_MB,
       b.Total_MB - round(a.used_blocks*8/1024) Current_Free_MB,
       round(used_blocks*8/1024)                Current_Used_MB,
      round(max_used_blocks*8/1024)             Max_used_MB
from v$sort_segment a,
 (select round(sum(bytes)/1024/1024) Total_MB from dba_temp_files ) b;

  TOTAL_MB CURRENT_FREE_MB CURRENT_USED_MB MAX_USED_MB
---------- --------------- --------------- -----------
     36011            1097           34914       35075




check the sessions that use temp tablespace:
col hash_value for a40
col tablespace for a10
col username for a15
set linesize 132 pagesize 1000

SELECT s.sid, s.username, u.tablespace, s.sql_hash_value||'/'||u.sqlhash hash_value, u.segtype, u.contents, u.blocks
FROM v$session s, v$tempseg_usage u
WHERE s.saddr=u.session_addr
order by u.blocks;

      SID USERNAME        TABLESPACE HASH_VALUE         SEGTYPE   CONTENTS      BLOCKS
---------- --------------- ---------- ---------------- --------- --------- ----------
      2749 TEST3 TEMP01     0/2004054495             LOB_DATA  TEMPORARY        128
      2750 TEST3 TEMP01     0/1950821498             LOB_DATA  TEMPORARY        128
      6481 TEST3 TEMP01     0/104254066              LOB_DATA  TEMPORARY        128
      9842 TEST3 TEMP01     0/1950821498             LOB_DATA  TEMPORARY        128
      8470 TEST3 TEMP01     0/1655124149             LOB_DATA  TEMPORARY        128
      8176 TEST3 TEMP01     0/487817532              LOB_DATA  TEMPORARY        128
      6449 SYS       TEMP01     1523493484/1950821498    HASH      TEMPORARY        512
      9926 TEST1 TEMP01     3849710509/887856235     HASH      TEMPORARY       2560
      9926 TEST1 TEMP01     3849710509/887856235     SORT      TEMPORARY      56192
      6639 TEST1 TEMP01     2351869958/4158575278    SORT      TEMPORARY     337792
      9730 TEST1 TEMP01     0/543173518              SORT      TEMPORARY     337792
      8959 TEST1 TEMP01     0/4158575278             SORT      TEMPORARY     337792
      1320 TEST1 TEMP01     0/2542463110             SORT      TEMPORARY     337920
      7905 TEST1 TEMP01     0/543173518              SORT      TEMPORARY     337920
      6852 TEST1 TEMP01     0/2631006892             SORT      TEMPORARY     409472
      6761 TEST1 TEMP01     0/231059081              SORT      TEMPORARY     409472
      7971 TEST1 TEMP01     0/4158575278             SORT      TEMPORARY     409472
      9060 TEST1 TEMP01     0/4158575278             SORT      TEMPORARY     409472
      7873 TEST1 TEMP01     0/4158575278             SORT      TEMPORARY     409472
      7448 TEST1 TEMP01     0/887856235              SORT      TEMPORARY     409472

20 rows selected.



However, the tempspace can be used by any open cursor in that session. The current SQL is not necessary the culprit. In that case, we can check it from v$sql:
   
col hash_value for 999999999999
 select hash_value, sorts, rows_processed/executions
 from v$sql
 where hash_value in (select hash_value from v$open_cursor where sid=7448)
 and sorts > 0
 and PARSING_SCHEMA_NAME='TEST3'
 order by rows_processed/executions;

   HASH_VALUE      SORTS ROWS_PROCESSED/EXECUTIONS
------------- ---------- -------------------------
    887856235      30506                .000196676
   2631006892      30227                .001323276
   3490377209        632                46993.6709

 the SQL 3490377209 sorts lots of rows every time. It used most of the tempspace in this session.

Saturday, August 6, 2016

Insert Multiple records at once

CREATE TABLE emplyee
2 (
3 emp_id NUMBER NOT NULL,
4 join_date DATE NOT NULL,
5 email VARCHAR2(100)
6 )



 declare
2 begin
3 for i in 1..100000
4 loop
5 insert into emplyee values (i,'13-APR-2010','xyz'||i);
6 end loop;
7 end;
8 /

PL/SQL procedure successfully completed.

 declare
2 begin
3 for i in 100001..200000
4 loop
5 insert into emplyee values (i,'13-APR-2011','xyz'||i);
6 end loop;
7 end;
8 /


PL/SQL procedure successfully completed.


commit;

Check the count of the table






Datapump Import (IMPDP) is not ignoring Index Statistics?


Datapump Import (IMPDP) is not ignoring Index Statistics?

it is an expected behavior. It seems that, Oracle has automated the statistics collection during index creation/rebuild starting from Oracle version 10.2.0.1.

This behavior of statistics collection for indexes is controlled by the hidden database parameter ‘_optimizer_compute_index_stats’. The default value for this parameter is TRUE (force index stats collection on index creation/rebuild).

To confirm this, check the parameter setting in the database.
#######################################################
 SELECT
a.ksppinm Param ,
b.ksppstvl SessionVal ,
c.ksppstvl InstanceVal,
a.ksppdesc Descr
FROM
x$ksppi a ,
x$ksppcv b ,
x$ksppsv c
WHERE
a.indx = b.indx AND
a.indx = c.indx AND
a.ksppinm LIKE '/_optimizer_compute_index_stats' escape '/'
/

PARAM                          SESSIONVAL      INSTANCEVAL     DESCR
------------------------------ --------------- --------------- -------------------------------------------------------
_optimizer_compute_index_stats TRUE            TRUE            force index stats collection on index creation/rebuild

###################################################################
Here, we are. ‘_optimizer_compute_index_stats’ is set to TRUE (default) in our case.

To avoid statistics collection during the import (IMPDP) process, we can set the parameter ‘_optimizer_compute_index_stats’ to FALSE (recommended by Oracle itself) as follows.

SQL> alter system set "_optimizer_compute_index_stats"=FALSE;



Reference:

EXCLUDE=STATISTICS Or EXCLUDE=INDEX_STATISTICS During Datapump Import Still Analyzes The Indexes (Doc ID 793585.1)




How to lock/unlock statistics on a table?

How to lock/unlock statistics on a table?

In certain cases you may want to lock statistics in a table in certain cases, for example if you want a table not be analyzed by automatic statistics job but analyze it later or in cases where you want prevent from analyzing statistics in cases where data in the table doesn’t change.

The following example shows how to lock table statistics and what happens when one tries to gather statistics on table that has statistics locked.

— create table
SQL> create table test ( x number );

Table created.

— create index
SQL> create index test_idx on test(x);

Index created.

— shows when stats is not locked the value of stattype_locked is NULL
SQL> SELECT stattype_locked FROM dba_tab_statistics WHERE table_name = 'TEST' and owner = 'SCOTT';

STATT
—–
— lock statistics
SQL> exec dbms_stats.lock_table_stats('scott', 'test');

PL/SQL procedure successfully completed.

— shows when stats is locked the value of stattype_locked is ALL
SQL> SELECT stattype_locked FROM dba_tab_statistics WHERE table_name = 'TEST' and owner = 'SCOTT';

STATT
—–
ALL

— try to gather statistics on locked table
SQL> exec dbms_stats.gather_index_stats('scott', 'test_idx');
BEGIN dbms_stats.gather_index_stats('scott', 'test_idx'); END;

*
ERROR at line 1:
ORA-20005: object statistics are locked (stattype = ALL)
ORA-06512: at “SYS.DBMS_STATS”, line 10640
ORA-06512: at “SYS.DBMS_STATS”, line 10664
ORA-06512: at line 1

— try to gather statistics on the index using analyze
SQL> analyze index ajaffer.test_idx compute statistics;
analyze index ajaffer.test_idx compute statistics
*
ERROR at line 1:
ORA-38029: object statistics are locked

— unlock statistics
SQL> exec dbms_stats.unlock_table_stats('scott', 'test');

PL/SQL procedure successfully completed.