The tag has no wiki summary.

learn more… | top users | synonyms

2
votes
1answer
39 views

MongoDB 100% locked periodically. MMS charts attached

Trying to diagnose what could be causing intermittent lock-up on MongoDB server running behind a Rails application. Hoping that someone might recognise the pattern of peaks and troughs in the charts ...
1
vote
0answers
39 views

MongoDB Performance Troubleshooting

I have a small MongoDB replica set (2.4.6) and it seems about once a week, the primary gets bogged and the load average spikes up. This app doesn't see a huge amount of traffic. It resides in EC2 ...
0
votes
1answer
18 views

Over 100% of stage done during DROP COLUMN

I'm running a DROP COLUMN on the primary key column (I know, it's terrible but I had to do it). There's a progress indicator: Stage: 1 of 2 'copy to tmp table' 107% of stage done I haven't been ...
-1
votes
1answer
23 views

SQL Server Express 2008 R2 limitations

When considering to use an Express Edition of SQL Server 2008 for a system that officially is only tested with full editions, what do I need to know about the limitations? Memory, connections? What ...
0
votes
1answer
126 views

How to set MySQL's internal time zone support?

Today MySQL at Facebook posted the following about MySQL performance: Today we found a performance problem in a completely unexpected place - if TIMESTAMP data type is being used and MySQL is ...
0
votes
1answer
15 views

OpenBase server database connection troubleshoot?

I am troubleshooting a workstation/server instance in which an application hangs while interacting with our Windows 2003 Server OpenBase-hosted database. In short, the application will go into "Not ...
0
votes
0answers
12 views

Log ODBC queries including execution times to solve performance issue

We are facing some Perdormance issue in out web aplication which uses an ODBC Connection, i would like to log running queries to analyse where the problem is, Is there any way to make ODBC log the ...
1
vote
1answer
177 views

InnoDB Buffer pool hit rate missing from engine status output

I want to check the buffer pool hit rate for InnoDB on MySQL but when I query the database the hit rate seems to be gone from the results: Using query: SHOW ENGINE INNODB STATUS\G ...
0
votes
1answer
52 views

Database server's Load reaches very high values while nothing seems to use CPU, what could be the reason?

top - 16:33:08 up 155 days, 6:05, 5 users, load average: 27.93, 35.31, 31.34 At this moment it only shows 27.0 but the behavior is like so: While mysqld uses 0% cpu the load raises to high values ...
3
votes
1answer
1k views

Maintenance of tables: do I need to REINDEX a table after truncating and repopulating?

I have a table with about 2 million rows in it of transactional data that we use for analytics. Every week we reload this with new data, so we've been using TRUNCATE to clear it out and then inserting ...
0
votes
2answers
45 views

No. of databases or no. of tables?

I am running three different sites with ImpressPages CMS v 2.6.. ImpressPages is built on PHP 5.3 and MySQL 5. Each site have about 33 MySQL tables and the databases is using MyISAM engine. I have ...
2
votes
3answers
624 views

Speeding up SQL Server temp table processing with a RAM Disk

A system we are developing consists of a Web app frontend, and a backend that does a lot of data processing using stored procedures in SQL Server 2008 R2 (please, don't ask why...). These stored ...
0
votes
0answers
64 views

Disk IO slower when outstanding IO requests are less than 32

I moved the databases from one server to another and general remark from users is that its slower. The old server was on windows 2003,64 bit, SQL 2005 Ent edition(32 bit) whereas new one is Windows ...
0
votes
1answer
557 views

MongoDB Locking - Very, very, slow to read

This is the output from db.currentOp(): > db.currentOp() { "inprog" : [ { "opid" : 2153, "active" : false, "op" : "update", "ns" : "", ...
2
votes
2answers
593 views

Too much I/O generated by postgres stats collector process

I am using XenServer with several virtual machines having local postgres databases. Even when all applications are unused and the databases are idle, each vm causes constant storage network traffic ...
0
votes
2answers
119 views

Postgresql performance enhancement

I have my setup like this: Two separate instances of the database on a clustered environment. Both instances are on dedicated servers each carries up to the standard configurations. Instance one ...
0
votes
1answer
269 views

mysql database config optimization

Have a heavily trafficed database running mostly innodb and would like to better optimize the mysql config. Server has 32Gb ram and the biggest tables are ~18Gb innodb. I think I have done all the ...
1
vote
2answers
1k views

How to install Sphinx on CentOS 6 where the DB and App server are separate servers

First what is the best way to install Sphinx on a centOs server rpm -ivh http://sphinxsearch.com/downloads/accept.php?file=sphinx-2.0.6-1.rhel6.x86_64.rpm yum install sphinx didn't seem to work. ...
0
votes
2answers
122 views

PostgreSQL, automate REINDEX, Windows environment

I have a couple of PostgreSQL tables (9.1) which are inserted to / deleted from often. Over time they suffer from index bloating even though the autovacuum is configured and runs regularly. I'm ...
1
vote
1answer
2k views

How to calculate max_connections for PostgreSQL and default_pool_size for pgbouncer?

Is there a rule or something I can use to calculate a good number for max_connections, default_pool_size and max_client_conn? The defaults are odd. PostgreSQL defaults to max_connections=100 while ...
3
votes
1answer
3k views

How can I tell if NUMA is enabled on a MongoDB server?

Our mongodb process is consistently using >100% of our CPU (this is on an Ubuntu 64-bit server on Linode) and we're casting about for performance improvements. One suggestion we found was that ...
-1
votes
3answers
460 views

Redirect MySQL queries to another server [closed]

In order to lower system usage I'm planning to use another server to store my databases. so how can I redirect MySQL queries to another server or make MySQL to store databases on another server?
1
vote
2answers
214 views

Low priority batch processes on live Mongo database

We want to run MapReduces on our live Mongo database, mainly so that we can extract metrics. However, we've had some bad outages caused by these MRs bogging down the Mongo server (in particular 100% ...
1
vote
1answer
59 views

Is there a “rigorous” method for choosing a database? [closed]

I'm not experienced with NoSQL, but one person on my team is calling for its use. I believe our data and its usage isn't optimal for a NoSQL implementation. However, my understanding is based off ...
1
vote
1answer
194 views

Is there a negative impact to using SQL Server with a lower compatibility level

We have SQL Server 2008 R2 which we are using for a database with a compatibility level set as 2005 (90). We will by upgrading it to 2008 at some point, but in the meantime I would like to know if ...
0
votes
1answer
96 views

ft_stopword_file not picked up

I have a VPS server with a company called Webfusion. I want to remove some or all of the FULLTEXT stopwords because some specific words needs to be searchable with my DB content. I opened ...
-1
votes
1answer
418 views

MySQL runs at >=100% CPU, heavy disk I/O?

Recently my Debian Linux server has been experiencing slow web server response times. I've investigated and it seems that MySQL is the culprit, yet there are no slow queries indicated by the slow ...
1
vote
0answers
256 views

Intel cpu hyperthreading on or off for ibm db2? [closed]

Has anyone ever done any database performance comparisons with hyper-threading enabled vs disabled? We are running ibm db2 and I'm curious if anyone has an recommendations for enabling hyper-threading ...
0
votes
1answer
106 views

Server Performance

I know very little about performance tuning of servers etc... so i thought i'd put this up here as i start some research on it, just to get some direction. I am in the process of migrating from my ...
0
votes
1answer
74 views

Why does MySQL use a different index for my query in different versions?

I have a large-ish InnoDB table (about 800MB), and I'd like to count rows. I know SELECT COUNT(*) has issues in InnoDB, but one of the solutions I've seen is to create a secondary index, which is ...
1
vote
1answer
179 views

How can I tell if I would benefit from upgrading my Amazon RDS instance?

I have several sites with very high traffic - all hosted on Heroku and all of which access a db.m1.large mySQL Amazon RDS instance - and would like to know if there would be a performance benefit in ...
1
vote
1answer
200 views

How does MySQL 5.5 and InnoDB on Linux use RAM?

Does MySQL 5.5 InnoDB keep indexes in memory and tables on disk? Does it ever do it's own in-memory caching of part or whole tables? Or does it completely rely on the OS page cache (I'm guessing that ...
0
votes
2answers
147 views

Improving latency between developer machine and oracle db

It seems our developers are concerned with the latency they are getting between their dev machines at site a and the database which is at site b. Ofcourse the obvious thing is to have as little as ...
1
vote
1answer
301 views

Database Server Hardware components (order of importance), CPU speed VS CPU cache vs RAM vs DISK

I am new to database world and would like to know what are crucial hardware specs when it comes to database performance. I have searched the internet and found this so far (In order of decreasing ...
2
votes
1answer
250 views

MySQL performance on FreeBSD after moving db files from /var

I was running out of space on /var so I moved my db dir to /usr and noticed a significate decrease in performance. In addition I noticed that performance is much slower as well under any Jailed ...
2
votes
1answer
52 views

Consolidating SQL Server

We have a number of SQL Server 2008 R2 standard servers, each for a single application that we'd like to consolidate into one physical server. Running perfmon on these servers they're not using a ...
0
votes
2answers
166 views

Will a raid 10 help my db server in terms of trans/sec?

I've been reading about 10k drives being able to run 166 transactions per second vs 250/sec on 15k drives, which in both cases is just the number of rotations per second. What does this really mean ...
0
votes
3answers
143 views

How do multiple servers work in terms of databases? [closed]

I don't know an awful lot about servers, but I do know that there are many ways you can improve the performance of running a web application, in terms of hardware. For example, starting with a single ...
2
votes
3answers
1k views

mysql performance tuning, write, get db into ram

I am trying to improve the performance of a website by optimizing the Mysql server. In addition to general optimization I have a feeling that some write operations take an unacceptably long time. The ...
1
vote
2answers
784 views

Mongo has a huge log and sometimes hangs the box

My mongodb_mp.log is growing very quickly A tail -f of the file scrolls very quickly Do I need to look into connection pooling?
0
votes
1answer
235 views

How often would you run the Postgresql maintenance tasks

After reading the Postgresql documentation, we found that it's recommendable to run the Vacuum tasks daily: We recommend that active production databases be vacuumed frequently (at least nightly), ...
0
votes
2answers
96 views

Server configurations for hosting MySQL database

I have a web application which uses a MySQL database hosted on a virtual server. I've been using this server when I started the application and when the database was really small. Now it has grown and ...
0
votes
1answer
90 views

Understanding MySQL Query Cache and when to implement it?

On our current MySQL server query cache is enabled. Qchache_hits: 31913 Qchache_inserts: 50959 Qchache_lowmem_prunes: 9320 Qchache_not_chached: 209320 Qchache_queries_in_chace: 986 com_update: 0 ...
0
votes
1answer
230 views

Would it be okay to run Apache on one EC2 instance and MYQSL on another?

I'm currently running a VPS that uses ~1.5GB of ram. I'm thinking of switch to Amazon EC2, because access to our host is pretty slow, lots of downtime, etc. An EC2 small instance has 1.7GB, so I ...
1
vote
3answers
471 views

MySQL becomes unresponsive a few times per hour

I'm stuck trying to solve a MySQL issue. A few times an hour, for about 60s, MyuSQL becomes unresponsive, causing our site to be inaccessible during that period. I enabled the slow query log and found ...
1
vote
1answer
204 views

MySQL: view read/write proportion, per specific table

I'm optimizing the configuration of a MySQL server, running only Bromine. This is non specific to application, and was just noted for completeness. I am trying to determine if switching from MyISAM to ...
2
votes
1answer
85 views

How can I tell how my oracle databases configurations' differ?

I have two databases with the same data, running on the same physical server. They are performing differently (one is twice as fast as the other). I've compared the Initialization Parameters and ...
4
votes
1answer
107 views

Are there any performance differences between Oracle Entreprise and Oracle Standard editions?

Someone has asserted to me that the reason why one database is performing better than another (50-100%) is because one has Enterprise Edition and the other has Standard Edition. Given the same ...
1
vote
1answer
108 views

Is it possible to prioritise a tablespace for caching in RAM with Postgres

We have a large postgres database (over 100GB) running off a server with 32Gb of RAM. Some of the database we care much more about the performance of than other parts, so our idea is to put those ...
0
votes
1answer
164 views

Measuring Performance through SHOW INNODB STATUS;

When looking at the output of SHOW INNODB STATUS on mysql what are the most important values to be looking at, and what would be an indicator of poor performance? Specifically under FILE I/O and ...