Oracle DBA required to investigate performance anomolies in similar SQL

£10-15 GBP / hour

已关闭

已发布

大约 6 年前

£10-15 GBP / hour

We have two SQL statements that run at radically different speeds. It seems to be based on whether a column is placed in the WHERE or in the SELECT list. We would like this investigated and explained. Remote access to our test server can be arranged. The following statement runs slowly - 2.125 seconds: SELECT COUNT(*) FROM SBC WHERE [login to view URL] = 1 AND [login to view URL] = 40088609 AND [login to view URL] = 798120609; Despite it using the new index completely (including PLACED): CREATE INDEX "BTS"."SBC_PLACEDTARGETSPOTS" ON "BTS"."SALES_BREAKS_COMMS" ("CONTITEMPRGDETTARGETID", "CONTITEMPRGDETID", "PLACED") TABLESPACE "BTS_INDEXES"; Yet this statement, with the PLACED in the SELECT list and NOT the WHERE clause, runs quickly (0.238 seconds): SELECT [login to view URL] FROM SBC WHERE [login to view URL] = 40088611 AND [login to view URL] = 798120611; Note: The IDs in the SQLs are changed to prevent Oracle caching the results. Quick tests: PLACED, CONTITEMPRGDETID and CONTITEMPRGDETTARGETID in the WHERE - slow PLACED and CONTITEMPRGDETID but no CONTITEMPRGDETTARGETID in the WHERE - fast CONTITEMPRGDETID and CONTITEMPRGDETID in the WHERE, PLACED in the SELECT list - fast CONTITEMPRGDETID and CONTITEMPRGDETID in the WHERE, COUNT(*) in the SELECT list, no direct references to PLACED - fast PLACED and CONTITEMPRGDETID in the WHERE, COUNT(*) in the SELECT list - fast

Database Administration

Database Development

Oracle

SQL

项目 ID: 16926631

关于此项目

18提案

远程项目

活跃6 年前

想赚点钱吗？

电子邮箱地址

在Freelancer上竞价的好处

设定您的预算和时间范围

为您的工作获得报酬

简要概述您的提案

免费注册和竞标工作

18威客以平均价£22 GBP/小时来参与此工作竞价

@schoudhary1553

Hello, I can help with you in your project Oracle DBA required to investigate performance anomolies in similar SQL . I have more than 5 years of experience in Database Administration, Database Development, Oracle, SQL. We have worked on several similar projects before! We have worked on 300+ Projects. Please check the profile reviews. I can deliver your job with in your deadline. Please ping me for more discussion. I can assure the 100% job satisfaction. Thanks,

£12 GBP 在40天之内

4.9

(39条评论)

6.2

@tangramua

Greetings. I`m ready to investigate performance anomolies in similar SQL. As for me, I'm a professional system admin with 10+ years of experience. My main specialization is LAMP stack of technologies (Linux, Apache, MySQL, PHP) but also I have experience with Python, Node.js and .NET stack of technologies too. I have a deep experience with different PHP Frameworks such as Zend Framework, Symfony, Laravel, Yii, CodeIgniter, CakePHP as well as different open source solutions e.g. Magento Ecommerce platform, WordPress, Drupal, etc. I was working as a senior system admin at hosting services provider where managed and configured more than 300 various Linux/Windows servers. I can help you too. Please, send me the list of your requirements!

£13 GBP 在40天之内

5.0

(7条评论)

4.8

@mdo19

A proposal has not yet been provided

£14 GBP 在20天之内

5.0

(6条评论)

3.9

@netappservice

Hi, my name is Mustapha, I'm the DBA of a big company in Morocco. For your project, i have everything that's necessary to find the solution to your problem

£14 GBP 在40天之内

0.0

(0条评论)

0.0

@kcarpan5

Hi, It looks like the INDEX is the cause. I'm happy to take a look at it. Will need to further investigate what's happening. Please send me a message if you'd me to take it further.

£15 GBP 在20天之内

0.0

(0条评论)

0.0

@DBA4HireFederico

I worked on query optimization with several DBMSs, including Oracle. I held trainings on query performance and included this topic in my book "Mastering MariaDB". I will need to connect to the database to check the table structure, how the queries are executed and why. I will explain the current behaviour and how to avoid it. A special promise, reserved to customers that don't know me yet: no reward required if I will not be able to find the cause.

£48 GBP 在3天之内

0.0

(0条评论)

0.0

@Sky002

I've 5 years of experience working with Oracle Database. During that period I've optimized oodles of queries and scripts for the companies I've worked in. I feel, that experience will definitely come in handy while providing the solution to you.

£11 GBP 在40天之内

0.0

(0条评论)

0.0

@adriandutra

I think it so easy to solve this issue. You can use a subquery statement Relevant Skills and Experience I'm a DBA

£13 GBP 在15天之内

0.0

(0条评论)

0.0

@GujjulaParamesh

A proposal has not yet been provided

£12 GBP 在3天之内

0.0

(0条评论)

0.0

@mithlesh1984

I have 12 years experience as Oracle DBA. I have real time experience in tuning database & SQL query slowness.

£11 GBP 在20天之内

0.0

(0条评论)

0.0

@rjh5879145e0c2df

I have an experience of more than 8 years in Software company and was working on Oracle as a DBA. I tuned the whole package which was running for 28hours and set it to 4 minutes. So, I have a good knowledge of tuning too.

£11 GBP 在40天之内

0.0

(0条评论)

0.0

@tersedevendra

I worked on performance tunning for more than 5 years in different MNCs. I can assure you to deliver project on time with good quality of work. Looking forward for your further discussion for this project.

£11 GBP 在30天之内

0.0

(0条评论)

0.0

@fgordonie

Hello, These days Oracle performance tuning is hard, especially with the Optimizer Automation in 12.2, 12.2 and 18c. Have you done explain plans for the 2 querys? What else is going on at the same time? I'd look at v$sql, v$sqlarea and v$sql_plan to give you reasons why they differ so much. Also a 10046 trace. Do you flush the data buffers between running the SQL's? High hourly rate but not many hours needed to work this out. Regards, Frank

£55 GBP 在5天之内

0.0

(0条评论)

0.0

@Huafangwei

Hi, My name is Helen Wei. I am from Sydney Australia. I am now working for a Fortune 500 corporation as a senior DBA. I have over 20 years of professional DBA experience. I have got Oracle 11g and 12c OCM certification, which is the highest certification in the DBA world. In the recent 8 years I have been focused on database performance tuning and sql tuning. I have solved hundreds of performance issues for our clients all over the world in the energy and mine industry. This kind of sql performance tuning is my daily routine job and I am sure that I can solve it for you easily. To do this, I will investigate the base tables involved, the data distribution, statistics, index, execution plan and statistics, etc, find out the root cause and get the problem fixed. And, if it is allowed to rewrite the sql, it’ll be great. Contact me please, you’ll never suffer from database performance problem. Best regards, Helen

£111 GBP 在4天之内

0.0

(0条评论)

0.0

@palandenikhil01

Oracle DBA with 7+ years exp

£10 GBP 在5天之内

0.0

(0条评论)

0.0

@sharmaraj1982

My self oracle dba with 7yrs of exp in billing systems

£16 GBP 在10天之内

0.0

(0条评论)

0.0

@cosimomacafore

I will show you how to fix this with one email. I will only charge you $200.00 once you are happy and sorted. Trying to get my first bid here. Thank you for your consideration.

£13 GBP 在40天之内