Performance tuning done by adjusting database parameters or physical layout of the database.

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2
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1answer
361 views

Getting the most out of SQL Server with a million rows a day [closed]

I have a windows service that is inserting 1000 rows at 1 minute intervals to a SQL Server 2008 Standard database table that looks like: id, datetime, key_id, value key_id is a foreign key to ...
0
votes
1answer
1k views

How to measure a perfomance of SQL Server database? [closed]

I have the task to improve the performance of a SQL Server 2012 database (one of 4 in an instance) by 60% confirmed by corresponding statistics. So, I need to measure "performance" of the RDBMS ...
0
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0answers
233 views

After RAM upgrade on 32-bit Oracle server, ORA-04031: unable to allocate x bytes of shared memory

We are in the process of upgrading our Oracle database server at work, from SUSE Linux Enterprise Server 10.4 / Oracle 10g / 4GB RAM (Intel 32-bit) to Scientific Linux 6.4 / Oracle 12c / 8GB RAM ...
0
votes
1answer
35 views

Retrieve list of matched words in PostgreSQL

I'm new to PostgreSQL and really more than your more basic queries/inserts. I've created a TSVector column to my table that I'm searching and have set the column to look at the specific column in ...
3
votes
2answers
231 views

Tuning advisor with Extended events?

With SQL traces I was able to analyze them with Database Engine Tuning Advisor to obtain basic recommendations for perf. tuning(missing indexes, statistics,...). Now, with SQL 2012 and Extended ...
1
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2answers
3k views

How to optimize MySQL for large BLOB updates

I have a table that holds large BLOBs (up to 10M), and is updated frequently. The problem is that UPDATE statements can take up to 1 second to execute, and due to app design this blocks UI. I need to ...
6
votes
1answer
659 views

Optimizing PostgreSQL for transient data

I have several tables with 100-300 columns of integer types each, that hold highly volatile data. The datasets are keyed by one or two primary keys, and when refresh occurs, the whole dataset is ...
5
votes
1answer
491 views

How can a fill factor of 0 or 100 be the same?

As of my understanding, Fill factor of 80 implies that 20 percentage of each leaf-level page will be empty to enable future growth. I can't correlate how fill factor of 0 and 100 can be the same! Am I ...
0
votes
1answer
80 views

Indexes and Optimizations for Logging System

I'm designing tables for a new log system and am having trouble figuring out what indexes I'll need (I'm a developer, not a DBA), and am also open to any suggestions/criticisms/etc. for making the ...
2
votes
1answer
605 views

What causes InnoDB to write 100% more pages while slowing down answering queries?

I have a somewhat big database server: 4 processors, 32 cores, 288GB RAM, 2 ethernet cards bounded together, 2 independent RAID controller cards with 1GB cache each, 24 2.5" disks, being 8 SAS, ...
3
votes
1answer
497 views

Need help with long running query

UPDATE: Adding a clustered index to each work table covering all fields reduced the query run times to su-bsecond. I consider this question closed. Thanks for taking the time to read this post - ...
2
votes
2answers
904 views

PostgreSQL performance degradation over time on a write intensive db

I have observed a weird situation that over time the performance of a query (a combination of queries explained below) degrades, meaning at the start of testing (for a few minutes) the time of the ...
4
votes
2answers
8k views

Is my.cnf for mysql 5.5 is suitable and well tuned for below hardware spec?

My Hardware Spec Technology: Ivy Bridge CPU: Intel Xeon E3 1245v2 Intel Smart Cache: 8MB Cores / Threads: 4 / 8 Frequency: 3.4GHz+ / 3.8GHz Turbo Boost RAM: 32 GB DDR3 Hard disk: 2x 2TB SATA3 Raid 1 ...
4
votes
1answer
468 views

NuoDB with Amazon S3

I think about developing my new mobile and web app against NuoDB. I believe in their technology. The thing that I care the most is backup and restore in case of data corruption and read / write speed ...
5
votes
1answer
111 views

How to tell if database tuning is fruitful (PostgreSQL)

As a DBA, I regularly observe my database, tune up some queries (either getting the programmers to re-write it or add index or update statistics if that's what is needed, etc). I also tune up the ...
0
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0answers
278 views

PostgreSQL can't start after tuning some options

I'm having some issues with "too many clients" and I tried to change the max_connections param (currently 100). I tried to set some value like 300, but when I restart the service, I got this ...
7
votes
2answers
15k views

Could not continue scan with NOLOCK due to data movement

We run SQL Server 2000 and we get a few of these errors every night. Could not continue scan with NOLOCK due to data movement The query that throws this error is a large complex query that joins ...
1
vote
1answer
181 views

sp_setapprole taking 100 - 200 ms [closed]

SQL Server 2008 SP1 here. We have a machine where sp_setapprole calls take more than 100ms and they are done many times per user operation on an application. The developer says that in his setup, ...
1
vote
1answer
2k views

Planning simple CMS: How much relation?

I'm currently in the process of designing the database for a rather minimalistic Content Management System I'm working on alone. It should allow scalability while remaining speed, especially on boxes ...
2
votes
1answer
111 views

Slow Query Gets Even Slower After Indexing

I have a MySQL database with just one table containing 8 million records. I need to query the table to find a single record that matches a specific number: select * from my_table where ...
0
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0answers
46 views

Oracle User Profile for REST API

What sort of profile would you recommend for an Oracle user that is manifested through a RESTful API; particularly where there will be a lot of asynchronous requests? So we're talking about a ...
1
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0answers
6k views

Could Oracle ORA-08103 'object no longer exists' error be caused by size of undo_retention parameter?

Had a once-a-day long running data warehousing procedure that I had written that was failing about 50% of the time. Logs were showing ORA-08103 'object no longer exists'. ORA-12012: error on auto ...
5
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2answers
2k views

I get ORA-13605 when trying to run SQL Tuning Advisor from SQL Developer

When trying to use the SQL Tuning Advisor from SQL Developer I get this error. Tuning advisor was working some days before.
3
votes
1answer
465 views

Find least recently used mysql table index

I am cleaning up duplicate indices from (innodb)tables in a mysql database. The database has about 50 tables. While I can check for duplicate keys using pt-duplicate-key-checker, I was wondering if ...
1
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0answers
684 views

SQL Server Database Engine Tuning Advisor vs DMV queries

What is the best way to tune the indexes on my production database? I normally use the following query : SELECT user_seeks * avg_total_user_cost * (avg_user_impact * 0.01) AS [index_advantage], ...
1
vote
1answer
281 views

MySQL suddenly running very very slowly

I run a PHP/MySQL website on a fairly large server with 16GB RAM and 3 vCPUs. Everything was flying along until this morning when I noticed MySQL down. I tried to restart MySQL and first got the ...
4
votes
2answers
1k views

Could running ANALYZE on all databases on large InnoDB tables show some performance increase?

So we have an old database that was fragmented until we ran OPTIMIZE on all tables. The database/tables are about 100GB in size. Tables are InnoDB with heavy read/write activity. There are so many ...
2
votes
1answer
280 views

How do you figure out what planner cost constants to use in Postgres?

I'm using Postgres 8.4 right now. Performance has started to become an issue as our tables have grown in size and our queries in complexity, so I've started to look into some performance tuning, but I ...
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votes
1answer
205 views

when to use technology like hadoop?

I understand that MySQL and others support large enough data for storing and retrieving. I am also aware of the open source projects such as hadoop and mapreduce etc.. (only their purpose and what ...
0
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3answers
413 views

Custom SQL Server Computer Build

I hope this is the right place to ask this question. I'm a user at StackOverflow, and when I perused the StackExchange websites, this was the best match I could find. So, if I've posted in the wrong ...
3
votes
2answers
313 views

Is it important to release memory back to the server?

I have a SQL Server 2008 R2 instance running on a production system. I'm not a DBA; I'm more a developer, but my client is currently asking me: How important is it to release memory from SQL Server ...
5
votes
1answer
4k views

Can I safely kill OPTIMIZE TABLE on an InnoDB table?

MySQL's documentation for kill warns: Warning Killing a REPAIR TABLE or OPTIMIZE TABLE operation on a MyISAM table results in a table that is corrupted and unusable. Any reads or writes to ...
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2answers
2k views

Restore data from remote server using “.sql” file

I have a ".SQL" file which contains data at a remote server. I could download that file to my local machine and import data in my local DB, but because of network issues, and the size of ".sql" file ...
3
votes
1answer
149 views

What are some key configuration settings for using an InnoDb table for session storage?

I want to start clustering my PHP app servers but don't want to go for a sticky-sessions load balancing setup at this point. However, I want sessions that are persisted to disk and implement proper ...
2
votes
1answer
340 views

what does SHOW /*!50000 GLOBAL */ STATUS do ?

What is the difference between SHOW /*!50000 GLOBAL */ STATUS and SHOW GLOBAL STATUS I saw that in few scripts and tuning presentations the first command is being used. Is there a difference, ...
1
vote
1answer
425 views

Database Tuning Advisor can't find tables across two databases

I've got a Python script which accesses two SQLServer 2008 databases. If I run it and take a trace to capture all events that occur as a result of the script, and then put that trace through the ...
11
votes
3answers
14k views

MySQL table_cache and Opened_tables

I have seen people use the comparison of Open_tables and Opened_tables to assess whether the table_cache is too small in MySQL. However, I believe that Opened_tables is cumulative across uptime, so ...
0
votes
3answers
534 views

SQL Server : primary keys advice to my whitepaper needed

I've tired to explain to every new junior developer in our r&d team why he should use Primary Keys and how to do that. So I decided to write small whitepaper, which every new developer should ...
1
vote
1answer
147 views

Is it possible to allow write-through computed columns for legacy code that expects a column to be read/write?

I have this existing table for IP storage: CREATE TABLE [dbo].[IPAddresses]( [ID] [int] IDENTITY(1,1) NOT NULL, [IPv4Address] [varchar](15) NULL, [IPv6Address] [varchar](45) NULL, ...
4
votes
1answer
335 views

Is there a way to make SQL Server's Database Tuning Advisor use more than one core?

I'm using SQL Server's Database Engine Tuning Advisor to generate recommendations for performance improvements on my database server. For the "consuming workload" step, it appears to use all ...
4
votes
2answers
895 views

Website is too slow when number of records increases?

I have developed a web application called Referral Program, It it developed by using PHP, MySQL. Users can joining the website and when they introduce new members, he/she gets a commission. The system ...
3
votes
2answers
2k views

Connection Pooling for PHP based website using Oracle 11g database

I am using Oracle 11g database server and now I am getting to see that OCI's persistent connection isn't much of a use, and a new connection is created anyway when a new user accesses the page. I ...
5
votes
1answer
490 views

Tuning queries and indexes using index analysis tool

I've been pointed to this script from several places which apparently helps with designing indexes in Microsoft SQL Server: http://indexanalysis.codeplex.com/ The problem is I'm using Sybase ASA 11, ...
5
votes
1answer
698 views

Should I use a storage engine other than MyISAM to optimise these tables or should I get better disks?

There's a production database I'm working on, whose 4 largest tables contain between 4 million and 10 million rows each and about 15 fields each, with indexes on different field types (numbers, ...
27
votes
7answers
15k views

Is it better to store images in a BLOB or just the URL? [duplicate]

Possible Duplicate: Files - in the database or not? I was wondering if there's any good reason to still use blob fields in a database. A couple of years ago I worked with a DB with a bunch ...
11
votes
2answers
1k views

SQL Server: Has anyone used the large-page allocations tuning option?

Has anyone used the tuning option of using TF834 large page allocations. I was just reading an MS article on it and was wondering if anybody had used it and seen performance gains. Are there any ...
5
votes
1answer
8k views

How do you increase MySQL performance using current server resources?

I have a MySQL database and some of my queries became slow. Query time is not stable. Most of the queries are fast, but some of them (may be that reads and returns less data) take long time. I know ...
2
votes
2answers
11k views

SGA_MAX_SIZE and SGA_TARGET

We recently increased sga_max_size to 4g from 2g but didnt increase sga_target, is it ok not to increase sga_target?? reason we wanted to increase sga is to reduce wait time on sequential reads in our ...
4
votes
2answers
2k views

Creating partitions on a production database

I have a production MySQL 5.1 database that is running well but I want to improve query performances. I have never used Partitions and just going through the manuals. I have two tables that involve a ...
4
votes
1answer
340 views

Proper Database Partitioning

I had asked a previous question "Proper technique for storing users event data" and the correct answer in my opinion was to create a database partition. Now from what I have read on it there are ...