0
votes
2answers
51 views

How should I structure my time based index?

So I have this table in SQL Server 2008. Let's just say it's called TimeSheets. Now, that table has two columns I am concerned with. TimeSheetDate and UserCustomerKey. TimeSheetDate is a ...
0
votes
0answers
26 views

What Index can I apply to a GROUP BY, MIN() and WHERE MySQL Query

I have the following table: CREATE TABLE `wp_prize_draws_log_copy` ( `id` int(11) unsigned NOT NULL AUTO_INCREMENT, `pid` int(11) NOT NULL, `entry_date` date NOT NULL, `entry_time` datetime ...
0
votes
1answer
41 views

Best Indexing Strategy for Query with Equality[A], Range[B], Group By[C], AND Order By[count(P)]

I have a poorly performing query: SELECT user_id, count(item_id) as count FROM table items WHERE category = 'magazine' AND created_at > 1384754400 GROUP BY user_id ORDER BY count(item_id) desc ...
0
votes
2answers
135 views

MYSQL - Why does this SELECT get slower the further down the table?

My table: CREATE TABLE `wp_users` ( `ID` bigint(20) unsigned NOT NULL AUTO_INCREMENT, `user_login` varchar(60) NOT NULL DEFAULT '', `user_pass` varchar(64) NOT NULL DEFAULT '', ...
0
votes
1answer
125 views

How to optimize indexes on MySQL query with various sorts

I have an INNODB table levels: +--------------------+--------------+------+-----+---------+-------+ | Field | Type | Null | Key | Default | Extra | ...
1
vote
1answer
180 views

MySQL query optimization with aggregate ORDER BY

I have an analytics table that stores metrics aggregated the day level. I need to ask questions such as "For a given date range and client, what are the most popular items." The schema is as follows: ...
1
vote
1answer
89 views

Minimizing Page Fetches

I have a complicated database structure and am trying to use it to retrieve Records based on multiple selection criteria from several tables. As a general rule, is it better to attempt to use ...
1
vote
1answer
246 views

Would adding indexes to my foreign keys improve performance on this MySQL query?

Consider the following query: SELECT `locations`.`id` AS `location_id`, `locations`.`address`, `locations`.`lat`, `locations`.`lng`, `tickets`.`status_id`, `customers`.`name`, ...
4
votes
1answer
610 views

How to properly index hstore tags column to faster search for keys

I imported a large area of OpenStreetMap's planet.osm file into a postgresql database. The database contains a table called nodes. Each node has a geometry column called geom and a hstore column ...
2
votes
0answers
54 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 ...
1
vote
2answers
259 views

Query Performance Tuning on a huge table

I have the following table Transactions. The table looks like this: CREATE TABLE [dbo].[Transactions]( [TransactionID] [bigint] IDENTITY(1,10) NOT NULL, [PlayerID] [bigint] NOT NULL, ...
1
vote
1answer
106 views

Performance impact of including result column in indexed columns

I have a database (in MySQL, using InnoDB) that I am using for texture identification in a 3D image. In it, there will be a table of texels(texture pixels) with hue included, in the form of: texelid ...
1
vote
2answers
129 views

How to optimize this query?

Query: Select * from `t_event` where `create_user_id`=7 and (`event_create_date`)=('2012-12-18 00:00:00') and `event_type_cd`=11 and `domain_id` =602 and `job_id` =1 limit 1 Table structure: ...
1
vote
1answer
200 views

Simplify and optimize a complex query

Our site has a chronological event feed that uses MySQL. We have noticed that some of the queries tend to run for quite a bit longer than others. For example, some queries for our heaviest users take ...
1
vote
1answer
151 views

What would be a optimal index for this query in mysql

I'm trying to optimize this query. SELECT * FROM sales_reps WHERE account_id = 1 AND (state = 'enabled') AND (clients >= 5 OR revenue >= 10000) ORDER BY name, platform, client_group, ...
1
vote
1answer
92 views

What is the best relationship model for high performance?

I want to model a relationship between Customer and Transaction. However, because Customer is only described by a unique string and no extra info, I have two possibilities to implement it in the ...
5
votes
2answers
2k views

How can I improve the speed of a query on a 20 million+ row table?

I have a query that is used for getting internet traffic statistics of certain IP addresses. There are separate IP address fields for hosts and blocks of IPs called assignments. The data is stored ...
2
votes
1answer
115 views

Where to place non clustered index

Execution plan clearly showing that one of my table used in query is useing Clustered Index Scan. From this node, how can i guess that which columns should be part of my non clustered index key and ...
0
votes
3answers
2k views

Will more indexes on a table affect performance? [duplicate]

Possible Duplicate: How do indices impact query performance? How to know when/if I have too many indexes? Say ‘X’ report using some "where" condition in the statement so we are creating ...
1
vote
1answer
776 views

Index Strategies on Text or NVARCHAR(MAX) Fields

I have the following query (simplified for question) I'm trying to speed up for a read only DB ... SELECT [sysid] ,[Date]=CONVERT(CHAR, DATEADD(D, [date], '1800-12-28'),101) ,[From]=[from_addr] ...
0
votes
1answer
128 views

Creating Indexes to optimize query

I have this query and I want to increase its performance by adding appropriate Indexes. DELETE FROM MYTAB1 WHERE MYID1 IN ( SELECT MYID2 FROM MYTAB2 ); I am not familiar with the ...
4
votes
2answers
371 views

Why is a secondary index chosen over a clustered index for SELECT COUNT(*) …?

In this query: select count(*) from largetable; a secondary index is chosen: mysql> explain select count(*) from largetable; ...