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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5
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319 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
179 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 ...
2
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73 views

SQL Server 2012 Local SSD TempDB Slow

I have a production deployment using local SSDs for tempDB. I have 2 SSDs in a RAID1 configuration. I am seeing average reads of 1-2ms but the average writes are showing as 1377ms on all four of my ...
2
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57 views

Do OR conditions in Oracle SQL queries spoil index use / cause full table scan?

I have a query on Oracle 11g of the following type, which results in a series of highly inefficient full table scans: select t.Id, t.ObjectId, t...[other Tasks columns] , od1...[ObjectData1 ...
2
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73 views

poor and/or unreliable InnoDB performance

I recognize that there are a ton of posts like this, but after reading up on InnoDB performance problems, nothing I tried has helped. I have a database containing four InnoDB tables. The largest ...
2
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0answers
68 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 ...
2
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0answers
65 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
507 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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62 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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407 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
967 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 ...
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110 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 ...
2
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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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vote
0answers
19 views

Optimization Tips For MYSQL Tuner/Primer

So I have a site that has a crap ton of traffic. I see a decent amount of latency when the site has over 1,000 active visitors on it. I have new relic installed and it seems Im only using 10% of the ...
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30 views

Guidelines on best indexing strategy for varying searches on 20+ columns

I’m running a search engine for cars. It’s backed by a postgresql 9.3 installation. Now I’m unsure about the best approach/strategy on doing index optimization for the fronted search. The problem: ...
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0answers
24 views

Extended Events missing documentation

I have been looking pretty hard for the documentation regarding the RingBufferTarget <RingBufferTarget truncated="0" eventsPerSec="1370714" processingTime="7" totalEventsProcessed="9595" ...
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18 views

Database slowdown at random times using mirroing

Our web application suffers DB query timeouts a few times a day at random times. Can you help to work out the cause, e.g. deadlocks, mirroring (disk or network), etc? We have two identical database ...
1
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0answers
28 views

How can I reduce recursion in Couchbase?

Sometimes, you need to access a certain document (A), but you do not know the key for that document (A), as that data is stored in a different document (B). So now, if you want to fetch A, it looks ...
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17 views

Storing generated documents that can not be updated by changes in relationships

I have a system running with PostgreSQL and Yii Framework, which generates a few medical documents that, once ready, can't be changed. For example: If my full name comes out on this document today, ...
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16 views

Querying number of tries since last successful log, checking IP as well as user

I asked this question before on stackoverflow, but it might fit better here, since it is mainly about database performance. The actual question With performance in mind, how would you go about ...
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0answers
33 views

Significant difference between duration for querys in SHOW PROFILE and SHOW PROFILES?

I have use mysql profiler to optimize an opencart query which takes more than 10 seconds to executes. mysql> SHOW PROFILES; ...
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0answers
71 views

Why is this query stuck if there are no waits?

I am working with a vendor's activity logging system. One of the tables has 70+ million records and is constantly increasing at several hundred records per minute. They have a utility to delete old ...
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26 views

Oracle: separate column histograms for partitions

I have a partitioned table like MY_TABLE(PART_KEY, DATE_KEY, ...) with a local partitioned index on (PART_KEY, DATE_KEY). When I collect stats on the table, I end up with a HEIGHT BALANCED histogram ...
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59 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
25 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 ...
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0answers
34 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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55 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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0answers
161 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
146 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
74 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
342 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
72 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
125 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 ...
1
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0answers
86 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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0answers
75 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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0answers
80 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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0answers
328 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
159 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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0answers
61 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
176 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
100 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
136 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
127 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 ...
1
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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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0answers
320 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
322 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 ...
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0answers
113 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
303 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
159 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
2 views

Sysadmin tools for SQLAnywhere

I'm seeing a performance issue in a 3rd party application based on SQLAnywhere 7. The DB engine seems to be dramatically underperforming on the hardware provided. It seems to have a upper limit on the ...