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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6
votes
2answers
3k views

Why is my Azure SQL Server so slow?

We currently have a VM that is very underpowered and are proposing to move to an Azure VM with better specs. The problem is, the Azure VM is much slower than the original VM even though it is of a ...
0
votes
2answers
590 views

my.ini configuration for a huge server

I have developed a web based app in PHP MySQL and Flash Builder. It was running fine until a few days ago when the client began to connect a lot of users. Then the app started to freeze and sent ...
0
votes
1answer
36 views

Some tables don't have primary key, how can I fix this issue?

I have the following message when running myqsltunner.pl in past this was not present. How can I solve this issues? -------- Galera Metrics ------------------------------------------------------ [...
12
votes
2answers
420 views

Minimizing Indexed Reads with Complex Criteria

I'm optimizing a Firebird 2.5 database of work tickets. They're stored in a table declared as such: CREATE TABLE TICKETS ( TICKET_ID id PRIMARY KEY, JOB_ID id, ACTION_ID id, STATUS str256 ...
1
vote
1answer
118 views

Error in loading data using DB2 load command in DB2 10.5

I have a IBM DB2 database in our application. We have a monthly Java batch process which loads data in the tables using "load Replace" sql command. Around millions of record will be updated every ...
0
votes
0answers
9 views

SQL Server Express 2016 high CPU Usage as soon as I log into Windows

I have a Windows Server 2012 R2 configured for ASP.net applications that connect to SQL Server 2016 Express installed on the server. This server is a VPS with 3 cores and 1.5 GB RAM. The load on the ...
1
vote
0answers
12 views

Get missing index statistics in SQL Server 2014 [duplicate]

For example consider a database that has many SP and many query execute on it using ORMs. It's very time consuming that check every SP or profile all queries that ORMs generate for performance and ...
1
vote
0answers
56 views

Fastest way to shred large xml data into a table

I have a nightly process that shreds XML data from a 17 million row table (120 GB) into another table, it takes about 3 hours and inserts about 1.5 million records. I currently do a complete drop ...
3
votes
1answer
3k views

How to resolve RESOURCE_SEMAPHORE and RESOURCE_SEMAPHORE_QUERY_COMPILE wait types

We are trying to figure out root cause of slow running sql server queries hitting/fetching data from one of the database , size 300 GB, hosted on server with below configuration: Windows server ...
0
votes
1answer
18 views

Do dormant databases impact server performance?

On our web server, my team has been creating new databases in MySQL to manage backups. They simply create new database_DATE and copy over our live site. Which made me think today... Can having a ...
7
votes
3answers
465 views

Single service account running all SQL Servers

Is there any negative performance impact for using the same service account and agent account to run SQL Server and SQL Agent respectively for all SQL server instances running at a small company of ...
8
votes
1answer
1k views

What frequency of hash/sort spills into tempdb is concerning?

Our enterprise application uses SQL Server for data storage and is primarily an OLTP system. However, an important component of our application generates a significant OLAP workload. Our write ...
0
votes
1answer
135 views

Query running slow on script and producing error 500 when run in phpmyadmin

I have a query that seems to take a good 30 seconds to execute even when the query produces no results. There are 4000 lines within the database and queries that produce all results run within ...
6
votes
3answers
13k views

Mysql slowly uses memory until it starts to use swap

I am running a 1gb of RAM rackspace database server. For some reason in about 2 days the memory usage goes from using very little swap, to using 100mb. If I don't restart sql it will keep using more ...
1
vote
0answers
43 views

ms/write on tempdb data files are dead slow

I don't know why writes on my tempdb data files are extremely slow. ms/write on each of the tempdb data files reaches to more than 800 ms!!! that's even after I moved the 8 equally sized (7GB) tempdb ...
2
votes
1answer
199 views

CPU Time Slower in SQL Server 2014 than in SQL Server 2008

We’re upgrading a virtualized database server from an old SQL Server 2008 R2 Standard (vmware) to a new shiny SQL Server 2014 Standard server (hyper-v). We were doing some performance testing and to ...
3
votes
3answers
67 views

IN Clause - listing values VS query

My app runs a lot of queries like this SELECT ... FROM Table WHERE CategoryID IN (SELECT CategoryID FROM OtherTable WHERE ..) To save performance I decided to cache the second subquery in the ...
3
votes
1answer
656 views

Select * from statement execute very slowly, innodb io read speed is low

I have a very simple query " select * from ap_statistic " running in my servers. the servers have the same hardware and software configuration (CPU 8 core, mem :32G, OS: redhat 5.5, mysql version: 5....
-3
votes
1answer
144 views

How to achieve high performance management of a huge list of distinct strings [on hold]

I am trying to achieve high performance management of a huge list of distinct strings in SQL Server (but I'm open to suggestions of alternate platforms that might be more performant). My specific use ...
2
votes
2answers
677 views

Mysql improve Self join performance large table?

I have a task to help identify conflicting IP ranges , I want to highlight when one companies IP range falls within another's ... below is the sample table, I have converted the IP ranges from .dot ...
15
votes
3answers
6k views

Is the overhead of frequent query cache invalidation ever worth it?

I'm currently working on a MySQL database where we are seeing a large number of invalidations from the query cache, primarily because of the high number of INSERT, DELETE and UPDATE statements that ...
0
votes
0answers
32 views

MySQL insert with sub select slow

We are using Python and LOAD DATA INFILE to load data from CSVs into our staging database. From staging we have sql scripts moving the data into our actual production database. LOAD DATA INFILE is ...
0
votes
1answer
185 views

Application is hanging when database upgraded from SQL Server 2000 to SQL Server 2008 R2

Presently we are working with SQL Server 2000, the database is perfectly working with our software for retail sales counter application developed with VB 6.0. But after upgraded to SQL Server 2008 R2, ...
0
votes
1answer
32 views

How costly are InnoDB rollbacks?

I recently heard a fellow co-worker mention that InnoDB rollbacks are costly and negatively impact performance. How true is this statement? To give a context, we use spring+hibernate and set @...
0
votes
1answer
342 views

MySQL Config for server with 8gb RAM and 4 cpus

I have a server with 8gb ram and 4 cpus. I don't have enough time for testing and bench marking so I would like to get the advise of experts like you guys, let me know if something is wrong with my ...
2
votes
3answers
763 views

Oracle Compatible Parameter to set

Is there any difference in setting the Compatible Parameter to 11.2.0.0 vs 11.2.0.4 ? Are there any advantages / dis-advantages ?
2
votes
3answers
155 views

SOS_Scheduler_Yield wait type

I am having a process that has a last_wait_type as SOS_Scheduler_Yield and is inserting 100 records to a table. This process has been with this wait type forever with low CPU utilization %. There are ...
1
vote
2answers
27 views

MySQL CREATE INDEX slowing down

My analytics table has 190M rows, about 150GB ins size. Storage engine is MyISAM with key-buffer-size=16G myisam_sort_buffer_size=2G myisam-max-sort-file-size=200G. Machine has 32GB memory. While ...
0
votes
2answers
226 views

Please recommend changes for my.cnf

I am not having any performance problems per se but want to improve my sites' performance if possible. Would appreciate any advice for how I can improve my.cnf. I have just one server, not ...
0
votes
0answers
54 views

select * into taking too long

I have an SP where we preselect some data into temp tables using select * into. From my understanding it doesnt copy over index,constraints. For last week i have seeing performance difference for ...
-1
votes
1answer
66 views

How much data in one table before it hurts performance

I'm about to develop a database for a community. The database is MS SQL Server. Each user can create their own shop where they can advertise about their products. So let's say I create a table to ...
2
votes
0answers
90 views

designing mysql for large tables

Currently I've been assigned the task to research ways to speed up an existing project. It's going to be rebuild so we can start from scratch, the current implementation has been build by another ...
3
votes
0answers
69 views

Sample a Mysql table to increase performance

we are storing all our clients traffic data in a MySQL 5.1.73 database (MyISAM) and then we use it to generate user and internal statistics/graphs, always searchinng for a client id and a date/hour. ...
1
vote
4answers
247 views

mysql need help optimizing query

I have a table containing servers logs, and another table containing rules to match certain and drop them. The logs tables contains around 1 million rows, and there are about 20-30 rules. The ...
2
votes
2answers
2k views

Improve MySQL Query Performance - Too many records

I am using MySQL RDMS for a contact management system. Now a days my database grew in size and contains more than 1 million records. Checking duplicate phone numbers became a big issue during ...
1
vote
1answer
405 views

memory usage oracle query

We see Direct path read temp frequently in the database. It started with one query and later followed up to all the queries running in database at that moment. I understand that data is read from ...
0
votes
2answers
2k views

How to configure my.cnf for Mysql 5.1, which is using too much CPU?

I am new Database engineer. I am having trouble in my server which is using too much CPU on database query(simple count statement). I have googled about it, so i found out it depends on system ...
16
votes
2answers
403 views

Using MAX text or more specific, smaller type

Someone was reviewing my DDL code for creating tables and suggested, when they saw I saw using VARCHAR(256) fields for text I expect to be pretty small, like a first name or whatever, that I should ...
2
votes
2answers
165 views

Select the maximum aggregate value for a limited set of chunked/grouped rows in a large database?

I work on WordPress plugin which implements sitemap functionality. One of the steps is to build an index of sitemap pages for post entries. The logic required is roughly: determine last modified time ...
2
votes
1answer
555 views

Database design for a table with both bulk insert and single row insert

I have to design a table where records will be inserted in two ways. Bulk insert from a batch process from a delimited text file between 2 - 3 million rows in a short burst. Later the same records ...
0
votes
1answer
113 views

Speed up query that have joined tables and function calls

I have a Bootstrap Table that use server side pagination to display results from a query like this: SELECT Item.a, Item.b, Item.c, Info1.Name, Info1.Name, Info2.Name, ...
0
votes
1answer
112 views

MongoDB Tag-Aware Sharding Workflow

I wonder the work flow of sharding cluster in Tag-Aware Sharding. --- Sharding Status --- sharding version: { "_id" : 1, "version" : 3, "minCompatibleVersion" : 3, "currentVersion" ...
1
vote
1answer
844 views

MySQL: Optimize query with a range and distinct count

I have a query on a large table with millions of rows that looks like this: SELECT COUNT( DISTINCT clicks.tx_id ) AS unique_clicks_count , clicks.offer_id FROM clicks WHERE ...
0
votes
1answer
33 views

Designing database containing code metadata

I'm working on a program that disassembles programs and analyses the results. I decided to use SQLite to store the data, but I'm having trouble deciding on how to organize the data. The design I'...
3
votes
1answer
373 views

MySQL - Where can I find metrics on the performance of Blob vs file system?

I know and understand that there are performance hits in storing blob data in the database, but the blob portion of the data is going to be rarely retrieved/viewed, it is for smaller data (the vast ...
1
vote
2answers
40 views

How to find out why this query is in waiting state?

I have a query that has been several minutes in waiting and is not running at all. In the SQL Developer monitor session view it shows that query has been waiting for 667 seconds? How can I find ...
0
votes
1answer
111 views

Slow ranking values in MySQL

I have a table of around 30 million retail products, with various INT columns that describe sales counters and pricing at different retailers. I'm supposed to display well over 70 different rankings ...
6
votes
1answer
420 views

MS SQL high tempdb disk I/O during merge replication of BLOBs

Having a merge publication for replicating BLOBs (sql type - image), got very high tempdb disk I/O for my size of data. Publication is download-only and has no filters. High disk I/O is caused by ...
0
votes
1answer
767 views

Select Query takes more than a minute to retrieve data

I have a table that has 99 columns, all of them are not needed but they were there when we started. There is a Primary Key (Objectuid) which is a GUI and has the Clustered Index on the PK. The Table ...
1
vote
1answer
141 views

How to find High CPU queries

CPU utilization is very high and the SQL Server process is consuming a lot of CPU. We have run few queries and notice that there are a few SPIDs taking a long time to complete and these queries may be ...