In the context of a database, optimisation refers to the process of the query optimiser selecting the best query plan to execute.
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4answers
142 views
optimize big sql query
My query has to return a statistics for example for march containing productname and price and its sidedishes (1:n relation) with the right price of each sidedish and the right tax for each sidedish ...
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3answers
442 views
MySQL optimization - year column grouping - using temporary table, filesort
I have a transactions table which is having 600,000 records, I need to list the count for the dashboard on financial year basis. The table used is MyISAM. I tried adding index for the transaction date ...
2
votes
2answers
75 views
How to optimize a log process in MySQL?
In my project, I have about 100.000 users and can't control their behavior. Now, what I would like to do is log their activity in a certain task. Every activity, is one record which includes columns ...
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2answers
243 views
Slow insert with MySQL full-text index
I use a full-text index in a MySQL table, and each insert into this table takes about 3 seconds. It seems that MySQL rebuilds (a part) of the full text index after each insert/update. Is this right?
...
2
votes
1answer
33 views
Optimize UNION query in MYSQL
I have a problem with a UNION query in MySQL. We have 10 millions players on our website and we would like to select players with a multi-criterias system. For exemple, selecting US people, men, > 35 ...
2
votes
1answer
69 views
mysql: need help to optimize my query/table
I'm wondering if someone could help me optimize my tables/query to speed up a query. It is currently running ridiculously slow. I think a well-thought out index could help me. Any help would be really ...
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1answer
46 views
MySQL database schema design help needed
I am developing a PHP application expecting millions of records both parent and children. My goal is to design an optimized database design to achieve high speed and performance.
This application ...
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1answer
96 views
MySQL subqueries that use range based on values of main queries don't use indices properly
I think I've isolated a problem that has been affecting many of my queries lately.
And would like some help to figure out a solution for this.
Ok so my findings are that a normal query that runs very ...
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1answer
63 views
Optimization of a select statement
I'm using MySQL and have a table user_data like this:
user_id int(10) unsigned
reg_date int(10) unsigned
carrier char(1)
The reg_data is the unix timestamp of the ...
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0answers
133 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
votes
0answers
67 views
Optimizations for new SQL Server 2000 database that will act as email queue AND API database
Due to limitations put on me I've got to put my outgoing Email Queue in the same database as my customer information.
What are some optimizations I can make, specifically to the Email portion that ...
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0answers
58 views
How can I join one to one to (many to one) without using group_concat
I have a table structure as follows:
--
-- Table structure for table `emails`
--
CREATE TABLE IF NOT EXISTS `emails` (
`ID` int(5) NOT NULL AUTO_INCREMENT,
`email` varchar(255) COLLATE ...
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vote
0answers
157 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
499 views
SQL query optimization in Prestashop e-Commerce solution
I'm working on a layered navigation module within Prestashop e-Commerce solution.
I'm trying to optimize a SQL query which creates a temp table during execution. I think this is creating a ...
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0answers
30 views
Are there any disadvantages to partitioning on financial year?
Our current set up has one table per financial year (May 1- April 30). Each table has approx 1.5 million rows. We have about 8 years of data, and will obviously be adding each year.
The majority of ...
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0answers
27 views
Optimising table efficiency format integers only
I currently have a table with 1,136,053 rows and 5 columns in a MySQL table.
They are all integer values and appear to be slowing down as I am increasing the rows.
I have indexed each of the ...
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0answers
41 views
Hierarchical data best practices
I'm looking for a best practicies\databases to solve our problem:
Currently we are using SQL Server 2008 R2 with HierarchyId. It works ok, but we have a lot of performance penalties due to this ...
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0answers
46 views
MySQL query optimization when no row is returned
I am using explain to figure out what is happening in my query which is:
explain select t from c where u1_id = 1 group by t;
I see "Using where" in the Extra column of the resultset. But this only ...
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0answers
64 views
InnoDB tuning with 1G of ram limit
I am trying to calculate variable moving averages crossover with variable dates.
That is: I want to prompt the user for 3 values and 1 option. The input is through a web front end so I can build/edit ...
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0answers
18 views
Table partionning problem
I need your help for a partionning problem. We are using a "log_event" table which log a lot of events sent by our players (subscription, connection, play, share, etc...). We insert 5,000 row / s in ...
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0answers
69 views
What is faster - multiple access of table or using temporary table?
I have created two tables
create table one(ref_no int, name varchar(100), design varchar(100));
create table two(SNo int auto_increment primary key, use_date Date, ref_no int references one(ref_no), ...
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0answers
111 views
Which update is faster using join or sequential?
My this question is in sequence of my previous question I asked.
I could write two solutions using Stored Procedure instead of trigger or nested-query .
Both use a helper function ...
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0answers
44 views
Load time implications of storing data in multiple rows vs serialized data
I am currently storing data in fields as shown below. Each of these pricing fields has two database rows associated with it, and there is up to 24 of these tables for a house. This therefore means ...
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0answers
88 views
Optimization of an Oracle query
I have a view which is accessed via DBLink in Oracle. This view is made up of different tables. Now we have to execute queries on this view. Example:
Select * from Viewname@dblink where ...
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0answers
640 views
Query alternates between fast and slow execution
We have an Oracle 11g2 installation. I have a query which joins four tables of approx. 30,000 rows each. The join conditions mostly are simple equalities. There are some NOT LIKE on strings and some ...
