Tagged Questions
5
votes
2answers
1k views
Insert-heavy InnoDB table won't use all my CPU
I have a packet log database, which is almost never queried. It just needs to be fast on inserts. I'm using InnoDB because I'd like to maintain ACID compliance, since even losing a single packet could ...
1
vote
2answers
2k views
Scheduled optimization of tables in MySQL InnoDB
What is the best way to schedule automatic optimization of tables in a MySQL InnoDB database? Can I use events for example? I have recently had a big performance issue (when querying) with one of the ...
1
vote
1answer
1k views
16 Cores 12 GB RAM server MySql Configuration - my.cnf
The server takes 20+ seconds (wait time/slow IO response time) to response to a HTTP request even with memcached and APC installed. I believe this has something to do with MYSQL since the site as lots ...
4
votes
4answers
2k views
MySQL: Index when joining to tables not being used (Performance optimizing question)
I need to optimize the following query:
SELECT /* [things omitted] */ articles.blogpost_id, articles.id AS articleid
FROM blogposts
JOIN articles ON articles.blogpost_id = blogposts.id
WHERE ...
1
vote
3answers
3k views
I've got 16GB of ram, how should I configure MySQL Server?
I've got a dedicated production server with multiple cpus and 16GB of ram.
I would like to know how can I configure it better to take advantage of the server resources for better performance because ...
3
votes
3answers
853 views
MySQL Query Optimization : Indexing and Pagination
I'm adding pagination to my 'latest news' php script and running in to an issue.
SELECT sid, title, time, bodytext, author, url FROM news WHERE approved=1 ORDER BY time desc LIMIT $start, $limit
I ...
2
votes
0answers
134 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 ...
1
vote
2answers
135 views
How do I force a JOIN to use a specific index in MySQL?
I have a query that JOINs 2 tables; lineitem and part,
select
sum(l_extendedprice* (1 - l_discount)) as revenue
from
lineitem force index for join (l_pk),
part
where
(
...
4
votes
2answers
533 views
Is there a way to hint to query optimizer to MySQL which constraints should be done first?
This is my current query:
SELECT BusinessID as ID,
111151.29341326*SQRT(pow(-6.186751-X(LatLong),2)+pow(106.772835-Y(LatLong),2)*0.98838574205337) AS Distance from
(
SELECT *
FROM
...
2
votes
1answer
60 views
Slow Queries Not Logging
I am attempting to enable slow query logging on our server in order to identify any queries that could use optimization. Sounds simple enough, however my file is not being written to. I get no errors ...
2
votes
1answer
303 views
Why does MySQL only sometimes use my index for a range query?
I have a table of IP address ranges and their country, here is the structure:
CREATE TABLE `geoIP` (
`startBlock` int(11) unsigned NOT NULL DEFAULT '0',
`endBlock` int(11) unsigned NOT NULL ...
2
votes
1answer
279 views
MySQL query 'going away' on executing INSERT ON DUPLICATE UPDATE statement with a 12524 character blob
I have a mysql insert on update query like so
insert into table (col1, col2, col3) values (1,2,'huge blob with 12524 chars') on duplicate key update col3 = 'huge blob with 12524 chars';
col1, col2 ...
2
votes
2answers
163 views
In MySQL, should I add an index even if the query that scans the table is only ran once a month?
Concretely, is it worth it to add an index to a query that scans the table of a mysql database,
even if that index would only be used once a month?
For example, having a users a table and then ...
0
votes
2answers
151 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 ...
0
votes
1answer
123 views
Optimising MySQL query with lots of self-joins
I have an entity_relationship table that describes relationships between entities. Each relationship will have 2+ entities involved.
In some cases it can be said that one entity is a constituent of a ...
