Tagged Questions

2
votes
0answers
29 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 ...
0
votes
0answers
41 views

one vs two column index difference when doing JOIN query?

Let`s suppose that alfa,beta and gamma contains milions of rows so we need to create indexes obviously to get optimal performace for this query : SELECT * FROM alfa JOIN beta on beta.id = ...
0
votes
0answers
139 views

Why this query takes 500 seconds to complete even though I got all the compound index right?

I tried this query db.tablebusiness.find({ "LongitudeLatitude" : { "$nearSphere" : [106.772835, -6.186753], "$maxDistance" : 0.053980478460939611 }, "Prominent" : { "$gte" : 15 }, "indexContents" : { ...