Tagged Questions

3
votes
2answers
194 views

Configuring PostgreSQL for read performance

Our system write a lots of data (kind of Big Data system). The write performance is good enough for our needs but the read performance is really too slow. The primary key (constraint) structure is ...
2
votes
1answer
166 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, ...
1
vote
1answer
87 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, ...
2
votes
2answers
305 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 ...
2
votes
1answer
126 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 ...
2
votes
1answer
173 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
105 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
136 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 ...
3
votes
2answers
543 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 ...
10
votes
2answers
672 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 ...
0
votes
2answers
667 views

How fast should I expect to load data on a high performance computer?

I am considering a model where I use PostgreSQL COPY to copy data from a file into a table. I was wondering what kind of performance to expect on high-end hardware. An interval in MB/s would be nice ...
1
vote
2answers
453 views

Performance tuning OLTP query

I have following sqls executed million times a day, single execution isnt an issue but executing million times causing some performance issues..Thanks in advance for your help! NOTE: data can change ...