Tagged Questions
0
votes
2answers
55 views
How do I use subquery on the same table in MySQL?
I have a query like this which takes a really long time to run. The table is around 4 million rows.
DELETE FROM TABLE WHERE value_was IS NULL OR value_was <= value_now;
I'm hoping I could ...
0
votes
2answers
49 views
How to use and optimize subquery on 100 million rows
What I'm trying to do is running a job on more than 100 million domains which haven't processed before.
I have two tables, "domain" and "domain_setting", on every batch (10.000 domains per batch) I'm ...
2
votes
2answers
107 views
Query taking too much time
My query is taking too much time to execute. Please help me here.
mysql> explain
select pcm.catalog_id
from cat_produ_catal_map_defer pcm, cat_catal_catal_map_defer ccm, cat_catal_defer c
...
-3
votes
2answers
268 views
Optimisation sub query SQL Server
I would like to optimise the query below because it's actually taking 40% of the time in the real one. I HAVE to get the first line in the table 2 for each line in the table 1. The relationship is 1 ...
3
votes
1answer
2k views
MySQL: Optimize UNION with “ORDER BY” in inner queries
I just set up a logging system which consists of multiple tables with the same layout.
There is one table for each data source.
For the log viewer, I want to
UNION all the log tables,
filter them ...
3
votes
2answers
157 views
Do MySQL sub-queries essentially use as much overhead as separate queries?
If I have a query like this:
SELECT name FROM
(
SELECT * FROM `table`
WHERE id IN (1,40,300)
ORDER BY AnotherColumn
)
From a bandwidth and overhead standpoint, is that the same thing as doing ...
0
votes
0answers
101 views
Can I do a MySQL subquery across criteria with different number of results
I inherited a site which has a product search running Coldfusion8 and MysSQL(5.0.88). Both filling the search form with default values and the search take forever, so I'm trying to improve both.
...
1
vote
1answer
522 views
PostgreSQL 9.1 - Query on VIEWS taking a lot of time
Using PostgreSQL 9.1, we are having problems while executing queries on a VIEW of PostgreSQL. Following is the situation:
We have a partitioned Table "buz_scdr" over which we have built a VIEW ...
2
votes
5answers
259 views
Query optimization [Oracle]
The Query:
select JOIN_RESULT.batch_id as BATCH_ID,
JOIN_RESULT.unique_doc_id as DOCUMENT_ID,
JOIN_RESULT.brand as BRAND,
JOIN_RESULT.message_date_time as UPLOAD_DATE,
...
3
votes
1answer
2k views
mySQL query optimisation — multiple joins or select … where not in (select distinct…)?
Background
I have a Drupal install accessing a large users database (~200k rows) and my "People finder" functionality needs to access all those rows (in a random order). I don't seem to be able to ...
4
votes
3answers
236 views
Which is the most efficient way to run a particular select query?
If I run the following code:
select PolicyNumber, MAX(decpageid) as decpageid, Risk
from StatRiskDecpages
where PolicyNumber = 'AR-0000301132-04'
group by PolicyNumber, Risk
I get the following ...
5
votes
4answers
979 views
MySQL subquery slows down drastically, but they work fine independently
Query 1:
select distinct email from mybigtable where account_id=345
takes 0.1s
Query 2:
Select count(*) as total from mybigtable where account_id=123 and email IN (<include all from above ...
