An evaluation of whether a system works well enough to be fit for purpose. Normally performance refers to the speed with which a system completes an operation or set of operations over time.

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86 views

SQL Server CPU spikes - possibly non-query related - suggested indicators

I'm looking for suggestions for indicators I could monitor to discover what is causing these cpu "blunted spikes". Some known information: sqlserver.exe is confirmed as the process consuming the ...
4
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204 views

Extremely Slow StatMan query issue with #SP2010 farm

The issue I’m experiencing is explained in a blog-post I created for this, (easy to refer to and to manage the responses / solutions in 1 location) which can be found here: ...
3
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0answers
84 views

How to properly monitor the number of PostgreSQL database connections?

I tried to use a Nagios script for monitoring the number of database connections on a Postgres database and I reached this problem: these are counted as currently open-connections and measured every 5 ...
3
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0answers
161 views

Database under heavier load — all SQL queries start timing out after a period of hours/days

I make a web application which has experienced heavy growth in the past week and it appears my database is seizing up because of it. You can see that everything seemed to be OK until about 3AM this ...
2
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0answers
49 views

SQL Server 2012 STIntersects

I have one table, T_PIN, with 300,000 pins and another, T_POLYGON, with 36,000 polygons. T_PIN has this index : CREATE SPATIAL INDEX [T_PIN_COORD] ON [dbo].[T_PIN] ( [Coord] )USING GEOGRAPHY_GRID ...
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0answers
55 views

Find Most active databases that can be offloaded from a busy server

I am in the process of identifying the most active databases on the server and will be moving the databases off the current server to alleviate the load. The reason to do it is that our servers are ...
2
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0answers
381 views

Mysql slow writes

i have a strange problem with mysql. My selects goes fast. My insert/create/delete/drop/update go very slow. I have done some tests on 2 machines. My old machine and my new machine. Old is worst ...
2
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0answers
54 views

How can one improve the performance of a query that selects on a low cardinality column in MySQL?

I have a "State" column that has a low cardinality (three possible value), on which most of my queries perform an equality selection (WHERE col = 'blah') AFAIK you need something like a bitmap index ...
2
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381 views

MySQL: Improve performance for one row insert into table with unique constraint

I have a table with ~ 40 mil records, with a unique index on the url collumn, of type varchar(255). Now the insert speed is about 30/s, is this expected? how could I improve it? I can't use bulk ...
2
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0answers
856 views

Oracle high Paging Faults

What are the reasons that lead to terrible high Paging faults. The following is the topas information and background about the Environment. OS: AIX 6.1 Softwares: Oracle 11gR2 Paging Space:30720 ...
2
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0answers
107 views

How To Analyse Index Scans

I am using merge replication with SQL Server 2012. During a sync using a merge agent there are a large number of index scans. I can see this by running a profile capturing SCAN:Started and ...
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0answers
6 views

Need help tuning my.cnf file

I need help tuning mysql. Currently it is using a lot of CPU. I dont find any query that last longer than 3 seconds in SHOW PROCESSLIST and there are only around 20-25 running most of the time. Still ...
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21 views

Any way to speed up my queries in MariaDB with tables less than a 4 GB in size?

I'm doing some text mining work and a bit frustrated that queries are taking 6 to 10 minutes to run. My workstation has a 3.5ghz Xeon, 32GB of RAM, and 2 SSD as RAID 0. Is it possible to do ...
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0answers
21 views

“dynamic set” in a MySQL table

I have a table where one column will have a few values many times (maybe 20 different values). Now I would like to use something like the set to improve performance and memory consumption. The problem ...
1
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0answers
30 views

Database tuning and possibly unexpected results

(This is cross-posted from stackoverflow; I initially put it in the wrong place.) So I have a database that's working a bit slower than I would expect and I'd like to describe what I'm doing so ...
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0answers
46 views

Do supertables produce bottlenecks?

There are several alternatives to using polymorphic associations and one of them is to use the so-called "concrete supertable". From my point of view, this is the neatest solution and is pretty easy ...
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69 views

Poor performance in my pgpool cluster

I've configured a postgres cluster with pgpool2 using the following link. The replication seems to be ok, but I ran some benchmarks (pg_bench) and the performance is lower than a single node, for ...
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0answers
113 views

Postgres database zero down time production deployment

I need some idea about how I can deploy a financial application in production environment using PostgreSQL DB with zero down time. I have two servers in Master-Slave design. Currently I am giving ...
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0answers
44 views

Fastest way to get the length of the intersection of two text arrays in PostgreSQL

This is what I am currently using: CREATE OR REPLACE FUNCTION array_intersect(a1 anyarray, a2 anyarray) RETURNS anyarray AS $$ select array ( select unnest($1) intersect select unnest($2) order by 1 ...
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0answers
237 views

Fastest way to perform simple operations on 1 million rows

I have a simple table with more than 1 million rows in an InnoDB MySQL table. Here are the steps that I need to perform on each row: SELECT * FROM tbl where work_done=0 make some data processings ...
1
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0answers
55 views

Can XML columns in Oracle/MS SQL Server replace document oriented databases to some extent?

Just a strategic question: I am currently working with frequently changing data schemas and it takes a lot to keep track of versions and specific content. I do, however, have a classic OLTP ...
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0answers
115 views

Why does removing a RID by creating a clustered index lose parallelism and slow down execution by 2X

If I remove a RID lookup by replacing 2 non-clustered indices (non unique) with 2 identical clustered indicies (non-unique) where there weren't any before, why does this query slow down by a factor ...
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0answers
69 views

SQL server taking too much time in opening properties in SSMS

I am using sql server express 2008 r2 SP2 from about 2 years. Now a days when i try to check properties of database using sql server management studio it takes too much time(25 to 30 seconds) to open ...
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60 views

What is the most efficient way to create new MySQL database

I need to setup a development environment for several developers. Each of them needs to test the software with a "fresh" MySQL database. There is a SQL file with many CREATE, ALTER and INSERT queries. ...
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74 views

Oracle specifying join order hint

Oracle 2 node RAC 11G R2 I have a query (this is a simplified version, but still exhibits the same issue as the larger query) that looks like this: SELECT t1.trip_id, t1.origin, ...
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174 views

How to configure pgpool for reasonable speed

I have a problem with pgpool II configured in master-slave mode with replication on slony. I have configured postgres databases on each server to run as fast as they can and this was verified by me ...
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0answers
146 views

Firebird database performance after server upgrade/restart

Got a 350 GB database (more than 40M records plus 0 - 1000 BLOBs for each record in another table). After upgrading Firebird to version 2.1.5 (mainly because of filesystem cache issue) database became ...
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59 views

Performance of database with transactional data

There are lots of row modifications (several thousands of rows per minute) in our PostgreSQL database that stores transactional data. We have a problem because PostgreSQL runs vacuuming process and ...
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0answers
161 views

Performance Hit when upgrading to Oracle 11gr2

I am experiencing the same symptoms as noted in this question which was closed and does not have a satisfactory answer. Original Question We've recently upgraded from Oracle 10gR2 (10.2.0.4 ) to ...
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0answers
88 views

postgresql 8.3 possible checkpoint and memory misconfiguration

I am using postgresql 8.3 in a read/write heavy application where data are being written to the database from a background process while they are also being read/written from a web application. At ...
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0answers
112 views

How to make Greenplum 4.2.3 only scan the intended partition?

When I uses unnest() in a View, and uses that View in a select statement, Greenplum seems to fail in only searching for the intended partition and search through all the partition of the main table ...
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0answers
114 views

Most efficient way to sort data fields into SQL

I'm trying to decide on the most efficient way to sort various data values. Here's how the data arrives: Device X sends a text string "name=value&name2=value&name=value" On arrival that ...
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0answers
1k views

'Incorrect datetime value: for column 'last_login' at row 1'

i am getting below error: Last_SQL_Errno: 1292 Last_SQL_Error: Error 'Incorrect datetime value: '2013-03-10 02:00:00' for column 'last_login' at row 1' on query. Default database: 'platform'. ...
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259 views

Efficiently retrieve big amount of data based on date range

Table EVENTS TimeStamp |O.Name |Location |Source | 2008-11-12 |Pretorian|Európe |England | 2009-12-24 |Lex Rosa |Európe |Italy | 2010-01-01 |Nasdaq |USA |Whasington | ...
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0answers
273 views

How to calculate running total based on dynamic values?

I need to calculate the running total in which the target column is changing along with the time. Its something which aws does. Charging based for only what you use. So how do I aggregate sum of ...
1
vote
0answers
110 views

Why is this table structure so slow to CRUD?

I have a table that I am using for queuing emails. Unfortunately, adding to or reading from this table becomes horrendously slow after adding about 50 records. -- Table "mail_queue" DDL CREATE TABLE ...
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0answers
259 views

Finding the bottleneck by analyzing Munin graphs

We’ve been experiencing some issues with our database server during peak hours. In our Nginx error-log we can see that a lot of requests get timed out. The requests are also very slow. We have had ...
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0answers
156 views

Multi-Table Join to Single Destination

I am having a serious performance issue with join together four tables and placing the results (in a certain permutation) into one destination table. I am using MSSQL 2008 and good ole T-SQL. To ...
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0answers
2k views

mysql taking too long to send data

I have a simple table with million of records (14,000,000) and for a simple query it is spending too much time "sending data". The table CREATE TABLE IF NOT EXISTS details ( id int(11) NOT NULL, ...
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0answers
18 views

Many temporary tables created on disk since mysql 5.6 upgrade

I recently upgraded MySql (from 5.5 to 5.6) on a Debian Wheezy server. Drupal 7 and a PunBB board are installed on this server (Drupal 7 database size: 54 M / board database size < 800 M). These ...
0
votes
0answers
11 views

Are mongodb bulk inserts really increase server perfomance (and faster)?

Bulk inserts always are faster in client side because of saving round-trips, but at the server-side is there any sensible performance improve? It seems the code for bulk inserts, just loops over ...
0
votes
0answers
5 views

Best design of mongo replica set for DB read/write speed

I'm building a Node app that uses MongoDB. Whilst it would probably be fine to have node and mongo sitting on the same VPS, I want to ensure that the MongoDB is backed up and maintain high ...
0
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0answers
14 views

Performance : MySQL replication or only one big server?

I'm searching about the best choice. We have to host a website with 10.000 - 20.000 visitors per day actually, growing. At the beginning, which would be the best : Having 2 MySQL servers (12 GB ...
0
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0answers
23 views

Big Mysql table optimization

I have a table that I use to cache google translate API answers. Table structure is orig_string and group are indexes Now it has more that 1million rows with 35000 distinct values in group field. ...
0
votes
0answers
31 views

Efficient way to fetch/update X records in a loop

What I need is a simple process that handles requests. I have setup a simple table as follows: CREATE TABLE Requests ( id INT NOT NULL AUTO_INCREMENT PRIMARY KEY, request_param VARCHAR(250) ...
0
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0answers
23 views

Sql Server Standard VS Enterprise

I have been bench-marking SQL Server Enterprise and Standard, Enterprise is using Partitioning by month on the table. The table only has 3 fields, Date-time (DateTimeOffeset(3)), Value (integer in the ...
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0answers
68 views

Why has the backup time significantly increased?

I'm using Sql Server 2012. The problem is that the backup takes about twenty minutes now, whereas only a few days ago it took a matter of seconds. The database has increased by about a sixth since ...
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0answers
29 views

How can the performance of a query that has a condition on two fields of each row be improved?

I have an images table with approximately 5 million rows in it. For the purposes of this question lets say the table looks like this: CREATE TABLE `images` ( `id` int(11) NOT NULL AUTO_INCREMENT, ...
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0answers
92 views

index usages on table with recursive relationship

we are working on a project that uses jpa and oracle. In this project we have a table with a recursive relation: Create table alarm ( id varchar2(200), ... alarmcode varchar2(50), parent_id ...
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0answers
62 views

Performance measurement in PostgreSQL

When developing server-side stored procedures performance measurement is an important issue. EXPLAIN ANALYZE is very usefull, but when it comes to simple queries like SELECT name FROM clients WHERE ...