Tagged Questions
0
votes
2answers
48 views
How to improve the query so as to reduce the time taken?
Consider i have 15 categories and each category has 6 sub-categories and now i have items table where i have to find 3 items from each sub-category based on the latest purchased date.
category 1 ...
5
votes
4answers
158 views
How to turn queries to perform efficiently in rails?
Consider i have a 15 categories and 6 sub-categories and i have table items where i have set of records where i have to fetch in the following manner
category 1 ---> level 1 ---> 3 items with ...
-2
votes
2answers
25 views
Find if there is a line on table : count or first?
I wish to do some optimizations on my SQL queries.
Without doing a performance test for it, what query is the most time-consuming ? I am almost sure they return the same result.
...
2
votes
1answer
43 views
How to optimize querying for thousands of IDs
Here are three consecutive queries with their Benchmark performance:
ids = @Company.projects.submitted.uniq.collect(&:person_id)
1.370000 0.060000 1.430000 ( 3.763946)
@persons = ...
1
vote
1answer
101 views
Optimize query to get unique (user) records from different tables
I got this query running perfectly already, but the problem is when my 4 tables get too big, it gets quite slow.
How can I optimize this?
SELECT
all_records.user_id,
users.NAME,
...
0
votes
3answers
190 views
Lightweight in-memory database
One of our needs is to create an temporal in-memory database, to then perform various inserts/selects/updates.
At a glance SQLite satisfied all our needs. Connection to an in-memory SQLite DB can be ...
0
votes
2answers
69 views
Effeciently querying User's name from “foreign key” ObjectId
For example I have models User and Post
User
{
"_id": ObjectId("pretendThisIsAUserObjectId"),
"name": "someUser"
}
Post
{
"_id": ObjectId("pretendThisIsAUserObjectId"),
"title": ...
8
votes
3answers
219 views
Why are individual SELECT queries running when an all-encompassing SELECT already ran? (Rails/ActiveRecord)
I have the following code (note the includes and the .each):
subscribers = []
mailgroup.mailgroup_members.opted_to_receive_email.includes(:roster_contact, :roster_info).each { |m|
subscribers ...
1
vote
1answer
190 views
Recommendation “to optimize the response time of an SQL query”
I would like to know what are the best solutions to optimize the response time of an SQL query for a table containing more than 2.000.000 records
As a solution, I thought of a virtual table by ...
0
votes
0answers
48 views
acts_as_taggable_on is this scalable?
I'm trying to use well-designed queries from the get-go as a best practice. In my controller I have the following:
def index
@resources = Resource.tagged_with("Subcategory")
@tags = ...
0
votes
1answer
229 views
Active Record optimization: .includes() generates a very slow DISTINCT query, how can I avoid it?
I've got two relations as follows:
class CfThread < ActiveRecord::Base
self.primary_key = 'thread_id'
self.table_name = 'cforum.threads'
belongs_to :forum, class_name: 'CfForum', ...
1
vote
2answers
422 views
mysql derived tables, performance, alternative
I have the following tables,
link_books_genres, *table structure -> book_id,genre_id*
genres, *table structure -> genre_id,genre_name*
Given a set of book_ids, I want to form the following ...
1
vote
2answers
67 views
What indexes should be created for this MySQL query
If I have the following query, what indexes could be created to speed it up?
SELECT `residentials`.*
FROM `residentials`
WHERE
(is_active = 1) AND
(
(created_at > '2012-02-20 20:51:56' ...
0
votes
4answers
319 views
Thumbs Up vote system
I want to create Thumbs Up vote system but I don't know how to do it in best way.
Here's my Entries#vote (controller/action):
def vote
if Entry.where(id: params[:entry_id]).first && ...
4
votes
1answer
225 views
Reducing the load of ability.rb in cancan
I have a large ability file that decides what exactly users can do by searching from a table of 'Roles'. Each role corresponds to something a particular user can do, for example, being able to add a ...
