Performance Comparison TDE Versus Plain Tablespace
Dec 9, 2008
Environment Setup
Oracle Server 11g on HP-UX
Oracle Client on Windows
I am using swingbench tool to generate load on DB and using OLTP like benchmark i am comparing the performance of plain data and encrypted data.
I have created two different database. one for tde and other for plain. I have populated same number of rows in both databases. Then i start running the benchmark and i use SAR to collect disk I/O's, VSAR to CPU usage.
From the sar report it seems that,
Oracle plain has faster transactions, it uses minimum CPU. But when look in tot the Reads/Writes TDE has lower than the plain.
If TDE needs to encrypt the data to store in the disks it should occupy more space than the plain data. Then the I/O should be more in TDE..
Note: Bcz the DB parameters are same, number of rows in the tables are same. File system and its block size are same. I will run the swingbench seperately for both the databases.
I am attaching the excel sheet for sar results. Let me know if you need more information
Oracle Database 11g Enterprise Edition Release 11.1.0.7.0 - 64bit Production PL/SQL Release 11.1.0.7.0 - Production CORE 11.1.0.7.0 Production TNS for Linux: Version 11.1.0.7.0 - Production NLSRTL Version 11.1.0.7.0 - Production
My os version is
Linux damdat01 2.6.18-128.7.1.el5 #1 SMP Wed Aug 19 04:00:49 EDT 2009 x86_64 x86_64 x86_64 GNU/Linux
My database is OLP system.
My question is what are the advantages and disadvantages having one single tablespace versus multiple tablespace?
Easy to maintain when you have single tablespace. but hard to track the IO issues if you have one single tablespace.
I have written a java code which reads 2 millions of data under a particular column from CSV file and store it into a set. Now there is a table in Oracle database which contains 10 millions of records for that particular column. Now, I want to form a SQL query which select those records under that particular column from the database table which is in CSV file but not in database table. For e.g.
If I consider the CSV file name as employee.csv and it has column called employee_name under which the records are as follows
Provide details about performance comparison between Oracle Sun Sparc 10 and IBM P7 server running oracle 11gR2 for OLTP system.
I know that licensing wise Sun will be much cheaper but i want to know other aspects such as performance, storage, transaction per second. Basically on a nut shell which server to buy for our OLTP system.
With a very large database (VLDB) for a data warehouse (DW) using primarily a STAR based schema in an environment in which time (both human and CPU) is orders of magnitude more valuable than storage capacity, is there any signficant difference in query performance when tables have all fixed length (CHAR) columns compared to tables with variable length (VARCHAR2) columns?
I realize this is one of those "in general" questions so considering "a given VLDB DW environment" with all other things being equal, what, if any, is the time based performance difference between a database of tables with all fixed sized columns versus one of tables with variable length columns ?
I am currently in the favorable situation in which I have excess amounts of memory available on the database server - a single node setup. The server only serves the single instance and no other processing. Database size is around 2.3tb and memory is 50gb. For the majority of processing, AIX is allocating a significant amount (anywhere from 30-40%) of the memory to the AIX file system cache (persistent pages).
I've been trying to find documentation about this, but have not had any luck yet. My guess is that it would be better to allow Oracle to cache this data - meaning increase the SGA target and max size to allow for a larger buffer cache. However, the nice thing about the AIX cache is if process memory is needed, the file system cache gives up pages. If the memory was allocated to the SGA, its pretty much locked in.
I have read several articles stating that a larger buffer cache is not always better, as a larger cache takes more management. But having both of the caches active seem to be a waste of memory, effectively storing the data twice - once in AIX persistent pages and a second time in Oracle database buffer cache.
If you have 3 tables (yr09, yr10,yr11) one with 2009 data, 2010 and 2011 data respectively. And a view (vw_yr091011) with a "union all" on all three.
Question: Will the performance be same for the following two queries ?
Question: Will Oracle read all 3 tables in the view when we search for only one year ?
select count(*) from yr09 where year = 2009;
-- vs
select count(*) from vw_yr091011 where year = 2009;
The following link says yes, the performance remains the same.
Link: [URL]..........
when I tried on a volume of 14000 records. The count came out same but the view took 50 more sec. And the explain plan shows it accessed all three tables.
I have two design alternatives and need to understand how expensive (speed) is one of them against the other for a medium size table (100K-200K records):
create table xyz ( f1 number not null, f2 varchar2(20) not null, f3 number not null, f4 varchar2(50),
[code]....
the idea is to optimize the design by using a PK instead of the 3 keys and there is a debate that searching a unique index field(2nd scenario) is of the same speed than searching a PK field (1st scenario).
I have a huge table (about 60 gb) partition over range. The index on this table is global index created on 4 columns together. I have a query which is running very slowly. The explain plan is showing the use of this global index.Explain plan is not showing pstart and pend because the index is global.
i am using 11.2.0.3.0 version of oracle. We are planning to move some ~40 tables/indexes to new encrypted tablespace as a part of TDE(transparent data encryption). Currently three tables are having size ~30GB and one having ~800GB other have <2GB in size. And tables/indexes are altogether placed in different tablespaces.
whether i should create as many no of encrypted table spaces as it was before as unencrypted tablespace? or I should create one encrypted tablespace and move all the tables/indexes into that?
we have a situation where both undo tablespaces were almost filled i.e UNDOTBS1 99% and UNDOTBS2 100% filled so i add data files to it and then i found a lot of blocking session and was just killing them through EM then i stop my front end listener and also down the service, now i don't have any blocking session but on EM a big WAIT is coming. alert log shows nothing serious, it was showing deadlock but now it is over as well.
All the analysis till now on our system proves that our system is clearly I/O bound and db sequential read is the biggest culprit.
We have even identified the index which is being affected by sequential read. I am thinking of creating a new tablespace with 32K blocksize (currently all table spaces are 8k) and migrate this index to the new space. That way, Oracle will have to do less number of reads to get the required data.
But is there anything wrong in having just one tablespace with a differnt block size? Or is there anything that I have to be watchful about while doing it?
Our production DB version is 11.2.0.1 and we do use DBArtisian. Everyday morning we check table space usage using that tool and it generates the below listed query. It used to run in 15 secs. But since one week it is running for 5/6/8 mins. I have updated the statistics on sys objects and tuning advisor created the execution plan. So, now it is running in 2 mins. Nothing has been changed in the DB configuration. I see the same query running in secs in dev environment. understand what might be the issue and how could I improve the performance of this query.
SELECT SUB.TABLESPACE_NAME, SUB.STATUS, SUB.EXTENT_MANAGEMENT, SUB.SEGMENT_SPACE_MANAGEMENT, SUB.TOTAL_SPACE_MB, SUB.USED_SPACE_MB, SUB.FREE_SPACE_MB, SUB.PERCENT_FREE_SPACE, SUB.CONTENTS, SUB.TABLESPACE_GROUP, CASE WHEN SUB.TABLESPACE_NAME = P.VALUE AND SUB.CONTENTS = 'UNDO' THEN 'YES' ELSE 'NO' END
One of our customer have problem with following sql statement:
SELECT c.table_name, c.column_name FROM user_tab_columns c, user_tables t WHERE c.table_name = t.table_name AND c.data_type IN ('CLOB', 'BLOB');
During execution it takes all the TEMP tablespace size(8GB).
I gather system stats (dbms_stats.gather_dictionary_stats(estimate_percent=>null)) but it doesn't resolve problem.Above sql statement works fine with RULE hint but I want to know what is the reason of problem with temporary tablespace.
Currently I am working on conversion project. We want to verify the both applications updated database values are same or not.
if you run same transaction in both application values are updated in the database. I want compare both database tables, its updated same values in table or any mismatch in the table, is there any tools available right now to compare the two rows values in same tables.
Select to_char(to_date('10-02-2006 10:30:00 AM', 'DD-MM-YYYY HH:MI:SS AM'), 'HH:MI:SS AM') as a1, to_char(to_date('10-02-2006 01:30:00 PM', 'DD-MM-YYYY HH:MI:SS AM'), 'HH:MI:SS AM') as a2, Case when to_char(to_date('10-02-2006 10:30:00 AM', 'DD-MM-YYYY HH:MI:SS AM'), 'HH:MI:SS AM') >
[code]...
from the above query i was expecting value '2' but its returning '1'. As I am using TO_CHAR its trying to compare characters. Is there a way, to compare times alone like less than, greater than?
When we create sql and some pieces of sql are implemented as oracle function. and we run this sql only once every day. I read article that function after first run located in cache. This part of cache ( with function ), is it really consume one oracle resources? Or it will be erased after while.
I need to populate a table based on the results of comparing sets of data. I decided to do this using MULTISET EXCEPT, but having created the structure, do not know whether it is actually possible, and if so, what syntax to use.
I have created:
CREATE OR REPLACE TYPE NUMBER_TBL IS TABLE OF NUMBER; /
CREATE OR REPLACE TYPE PACKAGE_OPTION_GROUP_OBJ AS OBJECT( ID NUMBER, benefits NUMBER_TBL ) /
CREATE OR REPLACE TYPE PACKAGE_OPTION_GROUP_TBL AS table of PACKAGE_OPTION_GROUP_OBJ /
I am expecting the result to be something like: ***comparisonTable*** GROUP_ID : 123 BENEFITS : 165 BENEFITS : 167 ---------------------------
However, I don't know if this is possible and if so, what the syntax would be.
At a later stage, I will need to compare the benefits between selectedTable and groupTable, where the GroupID's match, which is why I have the tables structured in this way.
I ran SPA for SQL workload of around 94 SQLs.In comparison report that is generated by SPA, there is a metrics "Top 94 SQL Sorted by Absolute Value of Change Impact on the Workload".
In this metrics there is a column "Impact on Workload". This column hold a value in percentage.how this is calculated by SPA. What formula is used by SPA to calculate "Impact on Workload".
