Whenever any transaction happen in database redo has generated for this transaction. Do select statement treat as a transaction as it doesn't modify any thing in database. And If select statement should not be a transaction, there should not be any redo generation for select statement.
So is select statement generate redo? If yes then Why ?
I have oracle 9i running on HP-UX, I would like to find how much redo we are generating in a given period of time, is there any script that I can use to get this information?
View 3 Replies View RelatedI learnt that logWriter writes in the redo log files when redo log buffer is 1/3 full, it means that 66 % of redo log buffer are always empty and never used,
if no, isn't a waste of memory (66 % always empty !)
I've a situation where I've very less redo logs generated. Let us say 10MB. Which solution will be better ?
1. Create one redo log group about 12 MB in size.
2. Create two redo log groups about 5 MB each in size as recommended by Oracle.
Even though solution 1 is also appropriate for me because I've less redo generated than the redo log group size. My whole redo will fit in this and I can raise checkpoint forcefully after certain period of time let us say every 3 seconds.
In one of our DB I found scenario one is implemented. So I want to know pros and cons of both of these practices.
I have some doubts about redo log files,
1) Can we fetch 'select statements' from redo log files through the use of log miner utility or any other?
(I think redo log file contains only insert,update,delete and DDL/DCL commands only)
2) If "No" to the above answer then how can i fetch all select statements fired on the system for a day or particular time.
(setting of sql_trace may be the one of them, but can it be possible for system level)
Today i noticed one problem with my database,my redologs switches in every 3mins,i also noticed there is no more transaction changes happening in database but still redo switches.
Fri Oct 05 06:10:05 2012
Thread 1 advanced to log sequence 79244
Current log# 2 seq# 79244 mem# 0: D:ORADATAORACIREDO02.LOG
Fri Oct 05 06:12:16 2012
Thread 1 advanced to log sequence 79245
Current log# 1 seq# 79245 mem# 0: D:ORADATAORACIREDO01.LOG
Fri Oct 05 06:14:28 2012
[code]......
why redo switch happening,any internal problem causes redo to switch .
redo generation. As I found the below statement in another forum."Undo segment generates the redo data also, because undo segment is database changes, so it generates the redo data also."
How a Undo segment can generate Redo and Undo datas.
Redo is getting generated very high. how to find out the reason ? database kept under 2 node cluster. chcked alert log trace and log writer trace files. pasted the content as below:
--alert log trace from node1 ( node2 also has same type of message ). Archive destination disk group - TXCOM_BACKUP_01 having enough space ( 80gb )
Mon Jan 7 00:49:10 2013
Thread 1 advanced to log sequence 448546 (LGWR switch)
Current log# 1 seq# 448546 mem# 0: +TXCOM_DATA_01/txcom/onlinelog/group_1.274.785770579
Current log# 1 seq# 448546 mem# 1: +TXCOM_DATA_01/txcom/onlinelog/group_1.302.802265189
Mon Jan 7 00:49:10 2013
[code]...
In the alert log, I am able to see the archive destination disk group ( TXCOM_BACKUP_01 ) is getting DISMOUNTED and again getting MOUNTED during every archive file generation. .
Mon Jan 7 00:49:20 2013
SUCCESS: diskgroup TXCOM_BACKUP_01 was mounted
SUCCESS: diskgroup TXCOM_BACKUP_01 was dismounted
SUCCESS: diskgroup TXCOM_BACKUP_01 was mounted
SUCCESS: diskgroup TXCOM_BACKUP_01 was dismounted
archive destination parameter in both nodes are not configured. it should read diskgroup name. ( +TXCOM_BACKUP_01 ) and corresponding size limit. Should i configure this ?
SQL> show parameter db_recovery
NAME TYPE VALUE
------------------------------------ ----------- ------------------------------
db_recovery_file_dest string
db_recovery_file_dest_size big integer 0
[code]...
should i bring the database to mount stage and set log_archive_max_proesses to high count ? now value is 2 ( default )
SQL> update t set a = 1 where b = 2; -- must have redo record
2 rows updated.
SQL> rollback;
the above redo record that uncommit changed must be written from redo buffer to the online redo logfile. why Oracle write the redo record that uncommit changed to the online redo logfile ? when it will be used?
We had our production database hosted on Oracle 9.2.0. Few months back we have migrated it to Oracle 10.2.0.4.0. After Migration I have noticed that redo generation has become very very high. In earlier case no. of log files generating in production hours were around 30 where as after migration it become around 200 files per day. I have run statspack report on this database. Report is saying that db block change & disk write is become very high. Parameter timed_statistics has also been set to FALSE. Even then there is not any reduction on no. of log file generation. I had used import export for upgrading the databases.
View 13 Replies View Relatedunderstanding a redo/undo concept . Refer following data
create table t(n number);
insert into t values(10);
commit;
now I update as following
update t set n=20;
As per my understanding the before image i.e. n=10 is stored in undo (to be used for rollback, transaction recovery and even in instance recover but not in media recovery) and after image n=20 is stored in redo (to be used for various recovery purposes including media recovery in case of consistent backup).
So it is redo logs for rolling forward and undo for rolling back making transaction, db consistent . If my above understanding is true then what is meant by the term 'redo required for undo'?
Also, if there are 2 database db1 and db2 connected using database link where we are populating t1 table in db1 using t2 table in db2 using db link where redo and undo will be updated db1 or db2?
When i was starting my database .there was an error
ora-00333:redo log read error block 203 count 8192.
We have one primary oracle database 10.2 and standby by database with no data guard. Initially we have 2 redo log group in primary and standby database.
We have recently add 2 more redo log and increase the size of log member from 50m to 200m in primary database. We don't have any problem in primary database.but in standby database we face a problem because we cannot open it. It always in mount stage in which . How we change the size of current redo log because we can't run. Alter system switch logfile command in mount stage.
In the following merge statement in the USINg clause...I am using a select stament of one schema WEDB.But that same select statement should take data from 30 schemeas and then check the condition below condition
ON(source.DNO = target.DNO
AND source.BNO=target.BNO);
I thought that using UNIONALL for select statement of the schemas as below.
SELECT
DNO,
BNO,
c2,
c3,
c4,
c5,
c6,
c7
[code]....
We are not using enterprise manager. Now, i want to generate ADDM report for the particular SQL stmt. How can i do that?
View 2 Replies View RelatedWhat is the use of using Hints within SQL statements w.r.t query tuning? How to know which hint to use when?
View 1 Replies View Relatedi want to select dynamic column names in my select statement in my function.
View 4 Replies View RelatedI am using JDBC to run a few queries from my Java program (multi-threaded one).I am facing an issue where a select statement is blocking a delete statement. From the java code point of view, there are 2 different threads accessing the same tables (whith different DB connection objects).
When the block occurs (which i was able to find out from the java thread dump that there is a lock on oracle), the below is the output:
SQL> SELECT TO_CHAR(sysdate, 'DD-MON-YYYY HH24:MI:SS')
2 || ' User '||s1.username || '@' || s1.machine
3 || ' ( SID= ' || s1.sid || ' ) with the statement: ' || sqlt2.sql_text
||' is blocking the SQL statement on '|| s2.username || '@'
4 5 || s2.machine || ' ( SID=' || s2.sid || ' ) blocked SQL -> '
6 ||sqlt1.sql_text AS blocking_status FROM v$lock l1, v$session s1, v$lock l2 ,
7 v$session s2,v$sql sqlt1, v$sql sqlt2
8 WHERE s1.sid =l1.sid
9 AND s2.sid =l2.sid AND sqlt1.sql_id= s2.sql_id
AND sqlt2.sql_id= s1.prev_sql_id AND l1.BLOCK =1
10 AND l2.request > 0 AND l1.id1 = l2.id1 AND l2.id2 = l2.id2;
[code]...
From the above it can be seen that a select statement is blocking a delete. Unless the select is select for Update, it should not block other statements is not it ?
I can not find the sql plan for insert statement,why?
Select sql_text From v$sql a
Where a.SQL_ID = '0yungrk19a277';
-------------------------------
INSERT INTO OS_USERBILL_ACTV_READ_MON_DT
(MONTHNO, MAILCODE, OPERTYPE, PROVCODE, AREACODE, DAY_TOTALCOUNT, TOTALCOUNT,
CREATETIME, MODIFYTIME, SENDER_TYPE, SENDER_DOMAIN)
VALUES
(:B9 , :B1 , :B2 , :B3 , :B4 , :B5 , :B6 , SYSDATE, SYSDATE, :B7 , :B8 )
[code]....
If we insert a row in a database table then the new row stays at database buffer cache in SGA (until commit), right?. The target table is not affected (before commit). The new row is saved after commit.
I saw a concepts at Sybex oracle 10g oca book (Page 406) as follows:
" INSERT statements use little space in an undo segment; only the pointer to the new row is stored in the undo tablespace. To undo an INSERT statement, the pointer locates the new row and deletes it from the table if the transaction is rolled back. "
My question is If the row is not saved at table before commit, if we issue rollback then how oracle delete from table? I think the new row is deleted from database buffer cache in SGA.
I am trying to record audit info about sql statement run by user (only one audit entry per specific type of operation such as create table, or insert table). Such as if a user create three tables, but database record only one entry of create table type per session.
I am giving you all the statement I issued...
SQL> create user saimon identified by abc1;
User created.
SQL> grant connect, resource to saimon;
Grant succeeded.
SQL> audit table, insert table by saimon by session;
Audit succeeded.
SQL> show parameter audit
NAME TYPE VALUE
-------------------- ----------- -------------
audit_file_dest string /u01/app/oracle/admin/orcl/adum
audit_sys_operations boolean FALSE
audit_syslog_level string
audit_trail string DBSQL>
[oracle@DBTEST ~]$ sqlplus saimon/abc1
SQL*Plus: Release 10.2.0.1.0 - Production on Thu Jul 19 21:45:09 2012
Copyright (c) 1982, 2005, Oracle. All rights reserved.
Connected to:
Oracle Database 10g Enterprise Edition Release 10.2.0.1.0 - 64bit Production
With the Partitioning, OLAP and Data Mining options
SQL>
SQL> create table TB1 (id number, name varchar2(20));
Table created.
SQL> create table TB3 (id number, name varchar2(20));
Table created.
SQL> select USERNAME, TERMINAL, OS_USERNAME, USERHOST, ACTION, action_name, OBJ_NAMe
2 from user_audit_trail;
USERNAME TERMINAL OS_USERNAM USERHOST ACTION ACTION_NAME OBJ_NAME
---------- ---------- ---------- ----------------- ----------------------- ----------
SAIMON pts/4 oracle DBTEST 1 CREATE TABLE TB3
SAIMON pts/4 oracle DBTEST 1 CREATE TABLE TB1
conn / as sysdba
Now my question is I have enabled statement auditing for session not by access. So only one audit entry should have been recorded for two table creation. Why database is recording every create statement?
SQL> show user
USER is "SYS"
SQL> SELECT audit_option, failure, success, user_name
2 FROM dba_stmt_audit_opts;
AUDIT_OPTION FAILURE SUCCESS USER_NAME
----------------------------------- ---------- ---------- ------------------------------
TABLE BY SESSION BY SESSION SAIMON
INSERT TABLE BY SESSION BY SESSION SAIMON
Why Blind select is better than Conditional select Statement?
View 10 Replies View Relatedwhen i modify a column of table tb_hxl_user,just as flowing:
Alter Table TB_HXL_USER Modify CREATE_DATE Not Null
now i select the table TB_HXL_USER,just as flowing:
select * from TB_HXL_USER;
it is hang,and i found the wait event is library cache lock in v$session_waits,why?how can i avoid this.
i have created one user SVC_LAMR and created one ROLE - SVC_LAMR_ROLE.
i have attachd this role to abv user SVC_LAMR.
i need to grant SELECT privilege on some tables ( from some other schema TPAOWNER ) to this role.so that this user SVC_LAMR can access those tables lying in TPAOWNER schema.
for e.g.
SQL> show user
USER is "SYS"
SQL> grant SELECT on TPAOWNER.USER_APPLICATION to SVC_LAMR_ROLE;
grant SELECT on TPAOWNER.USER_APPLICATION to SVC_LAMR_ROLE
*
ERROR at line 1:
ORA-01031: insufficient privileges
But, if i connect this user: TPAOWNER, and give SELECT privilge directly to this role, it is accepting.
i.e.
SQL> conn tpaowner/*******
Connected.
SQL> grant select on USER_APPLICATION to SVC_LAMR_ROLE;
Grant succeeded.
SQL> grant SELECT on USERS to SVC_LAMR_ROLE;
Grant succeeded.
If i inserted the values in table it gets inserting very few rows only.I dont know y it is?
View 15 Replies View RelatedI just completed a capture and I am trying to calibrate the workload but I get this error and I have not info about it.
I chmod the dir to 777 (just to make sure it wasn't permission) My sid is set to the correct db. Oracle_home, etc are set.
wrc MODE=calibrate REPLAYDIR=.
Workload Replay Client: Release 11.2.0.1.0 - Production on Tue Jul 27 14:59:33 2010
Copyright © 1982, 2009, Oracle and/or its affiliates. All rights reserved.
Errors in file :
ORA-15557: workload replay client cannot access the replay directory or the database version do not match the preprocessing one
This generates a CSV file in an directory. When it runs for the 1st time it take SYSDATE -7 data. After the 1st run it appends the data since the last run. Now my problem is the appending happens at the bottom of the file and every time the header appears. I want the header only the first time and the new data should keep appending at the top so that i get the latest data always at the top.
View 18 Replies View RelatedI'm looking for errors in alert.log, I thought that every "ORA-XX" would be a incident in adrci, but "i have missed" some ORAS-XX
I have a wrong job in my test environment which generates an ORA-12012 every 5 minutes. If we chech the alert.log trace we can see that there is a recor every five minutes (more of less)
oooo--oo--oo--oo--oo--oo--oo--oo--oo--oo--oo--oo--oo--oo--oo--oo--oo--oo--oo--oo
adrci> show alert -tail 2
2013-01-31 12:59:01.901000 +01:00
SMCO started with pid=23, OS id=20719
2013-01-31 13:00:23.033000 +01:00
Errors in file /u01/app/oracle/diag/rdbms/xe/XE/trace/XE_j000_20765.trc:
ORA-12012: error on auto execute of job "TEST"."WRONG_JOB"
ORA-04063: package body ""TEST"."WRONG_JOB"" has errors
ORA-06508: PL/SQL: could not find program unit being called: ""TEST"."WRONG_JOB""
[code].....
But, if we look for for incidents
oooo--oo--oo--oo--oo--oo--oo--oo--oo--oo--oo--oo--oo--oo--oo
adrci> show incidents
ADR Home = /opt/oracle/diag/rdbms/xe/XE:
*************************************************************************
INCIDENT_ID PROBLEM_KEY CREATE_TIME
-------------------- ----------------------------------------------------------- ----------------------------------------
23393 ORA 600 [kzsviver:1] 2012-09-27 09:19:55.054000 +02:00
23394 ORA 600 [kzsviver:1] 2012-09-27 09:20:13.540000 +02:00
23409 ORA 600 [kzsviver:1] 2012-09-27 09:56:35.688000 +02:00
[code].....
This ORA-12012 doesn't appears.
simply select and works great:
select 'CARAT Issue Open' issue_comment, i.issue_id, i.issue_status, i.issue_title, i.ISSUE_summary ,i.issue_description, i.severity,gcrs.Area_name, gcrs.sector_name,
substr(gcrs.stream_name,1,case when instr(gcrs.stream_name,' (')=0 then 100 else instr(gcrs.stream_name,' (')-1 end) ISSUE_DIVISION,
case when gcrs.STREAM_NAME like 'NON-GT%' THEN 'NON-GT' ELSE gcrs.STREAM_NAME END as ISSUE_DIVISION_2
from table(f_carat_issues_as_of('31/MAR/2013')) i inner join v_gcrs_with_stream gcrs on i.segment_id = gcrs.segment_id
where UPPER(ISSUE_STATUS) like '%OPEN%'
Now I want to callte two columns:ISSUE_DIVISION and ISSUE_DIVISION_2
if they are equal in new columns should be value 1 if are not equal should be 0,how can I do it ?
I have a question about select statements, as I am new to them and don't know how to work all the commands yet.
I'm making a select statement that is about half right... it is shown below:
select t.warehouse_id,
t.quantity_on_hand,
c.product_name
from pahtest3.inventories t
join pahtest3.product_information c using (product_id)
WHERE warehouse_id in (7);
I need to take this select statement and make it so it shows all the products that don't have any quantities in the warehouse in addition to the ones that are already being shown in that select statement.