Mariadb / mysql EXPLAIN to optimize data query
I am using mariadb to store a large number of measurements. A common query I do selects for a data range. It takes a little long, something like 10 to 20 seconds, and it gets worse and worse, so I…
Multi-criteria search query optimization in MySQL
I'm using MySQL 8.0.35 and I've two tables in my database: users and clients. Users can be searched by username, firstname, lastname, email, phone, document or even id. The clients table is used to track which users are clients of…
Postgresql – Optimize Finding Max Value per Year, String, Attribute
How do I get the rows for each year by scenario that are associated to the latest scenario for each year while being at-most prior month (future budgets & forecast scenarios exist as well) Fields: scenario (VARCHAR) Distinguishes between budget…
Laravel – Optimizing Query Performance for Matching Records Between Two Tables with Large Data Sets
I have a Laravel application where I'm retrieving data from two tables: LoginData and LocationStatus. The LoginData table contains records with a single IMEI, while the LocationStatus table contains multiple records for each IMEI, with a serverDatetime timestamp indicating when…
MySQL Query result Fetch Time is way beyond than Execution Time, how to Solve this?
I am using MySQL 8.0.27-18, with InnoDB as engine. I have a huge database, with few tables containing 100M+ rows in them. For example: TABLE_A with 110M and TABLE_B with 300M+ rows. Sometimes I had to join these tables in…
Optimising a query – PostgreSQL – XPATH
I have the query (PostgreSQL) which works correctly. with xml_test as ( select '<!--Build-Version: 1.564-REVb37dd024a8-20220530T1418--><tns:Message xsi:schemaLocation="https://appprod.be/Trivia/documents/Docs/XSDs/v1/T013 T013_v1.xsd" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:tns="https://appprod.be/Trivia/documents/Docs/XSDs/v1/T013"> <Header> <Agent>90015299</Agent> <SocialFund>299</SocialFund> <MessageId>T013</MessageId> <Timestamp RequestDate="2022-06-16T23:20:00" ProcessDate="2022-06-16T23:25:20" ResponseDate="2022-06-16T23:25:20"/> <Reference NRK="6e6806740a6ea06d7ca6ae7b31edeb8e" Requestor="90010299"/> <Result>OK</Result> <ReturnCode>ResponseOnly</ReturnCode> </Header> <Body> <Request> <TransmissionMethod>BULK</TransmissionMethod> <SocialFundCode>299</SocialFundCode> <FileNumber>9913894</FileNumber> <FiscalYear>2020</FiscalYear> <FiscalHouseHolds>…
Mysql – optimizing a query that is always scan full table
we have in our system a query that supposed to filter reports based on some factors the query is indexed , and when use explain it shows like it uses the indexes but the row numbers are the same amount…
Mongodb – How to index a mongo complex query
I really don't understand how to improve the performance of my query using index. db.Vendite.aggregate([{$group: { _id: { anno: "$anno", mese: "$mese", cod_age: "$cod_age", cod_int: "$cod_int", cod_cli: "$cod_cli", cod_linea_comm: "$cod_linea_comm", cod_sett_comm: "$cod_sett_comm", _art: "$cod_art"}, vendite_quantita: { $sum: { $add: […
Why is one of two nearly identical MySQL views so slow?
I've been investigating an issue with one of our application queries running very slowly and it seems to be related to a particular view we're using. Here is the full query with the selected columns omitted (there are 408 columns…
Postgresql – postgres parallel sequential scan
A parallel sequential scan is chosen, although an index exists on the column cpv.value. The value column has data type `text. This is the most costly step of the query plan. How do I tune this to reduce the cost/time…