Ecosyste.ms: Repos

An open API service providing repository metadata for many open source software ecosystems.

GitHub topics: query-optimization

zhangysh1995/awesome-database-testing

数据库测试资料 This repo is a collection of resources on testing database systems

Size: 75.2 KB - Last synced: about 11 hours ago - Pushed: 9 months ago - Stars: 165 - Forks: 20

course-files/BBT3104-Lab6of6-QueryOptimization Fork of gregrahn/join-order-benchmark

Instructional materials (course files) for the BBT3104 course (Advanced Database Systems) and the MIT8107 course (Advanced Database Systems). Topic: Query Optimization. Based on the IMDb dataset using PostgreSQL and the Join Order Benchmark (JOB).

Language: Python - Size: 275 KB - Last synced: about 22 hours ago - Pushed: about 24 hours ago - Stars: 0 - Forks: 0

zio/zio-query

Add efficient pipelining, batching, and caching to any data source

Language: Scala - Size: 874 KB - Last synced: 3 days ago - Pushed: 3 days ago - Stars: 147 - Forks: 22

tableau/query-graphs

A visualizer for queries - Hyper, Postgres, Tableau

Language: TypeScript - Size: 15.5 MB - Last synced: 14 days ago - Pushed: 15 days ago - Stars: 83 - Forks: 27

SpaghettiDB/Query-Executer

A Go-based projectbased project focused on implementing a query executor for a database engine. It provides functionality for efficiently executing SQL queries, managing worker threads, caching query results, and interacting with a storage engine. This project aims to offer a scalable solution for executing database queries.

Language: Go - Size: 110 KB - Last synced: 20 days ago - Pushed: 21 days ago - Stars: 0 - Forks: 0

tpetry/laravel-mysql-explain

Get MySQL EXPLAIN plans that are understandable for humans

Language: PHP - Size: 20.5 KB - Last synced: 19 days ago - Pushed: 2 months ago - Stars: 124 - Forks: 4

jmanhype/DSPy-Multi-Document-Agents

An advanced distributed knowledge fabric for intelligent document processing, featuring multi-document agents, optimized query handling, and semantic understanding.

Language: Python - Size: 134 KB - Last synced: 23 days ago - Pushed: 24 days ago - Stars: 4 - Forks: 0

EmilyShepherd/Query-Optimiser

Small project which estimates the cost of, and attempts to optimise, physical SQL query plans

Language: Java - Size: 121 KB - Last synced: 25 days ago - Pushed: over 8 years ago - Stars: 6 - Forks: 2

yunpengn/CG4001

CG4001 B. Eng. Dissertation @ NUS CEG

Size: 35.2 KB - Last synced: about 1 month ago - Pushed: about 4 years ago - Stars: 0 - Forks: 0

baqar-abbas/vet-clinic-database-redefine

vet-clinic-database is a postgreSQL database project that stores details of animals in a veterinary clinic and also generates specific reports using SQL queries.

Language: PLpgSQL - Size: 9.77 KB - Last synced: about 1 month ago - Pushed: about 1 month ago - Stars: 0 - Forks: 0

postgrespro/pg_pathman

Partitioning tool for PostgreSQL

Language: C - Size: 4.67 MB - Last synced: about 1 month ago - Pushed: about 1 month ago - Stars: 571 - Forks: 67

derhuerst/pev2-cli

Run the PostgreSQL Explain Visualizer 2 (pev2) from the command line.

Language: JavaScript - Size: 80.1 KB - Last synced: 15 days ago - Pushed: about 1 month ago - Stars: 21 - Forks: 1

deeepsig/query-translation

Implementation of papers on query translation

Language: Jupyter Notebook - Size: 5.58 MB - Last synced: 22 days ago - Pushed: about 2 months ago - Stars: 0 - Forks: 0

dwaraka-rashmi/QueryExpansion_SnippetGeneration

Language: Java - Size: 6.34 MB - Last synced: 2 months ago - Pushed: almost 8 years ago - Stars: 0 - Forks: 0

mstuefer/QueryOptimiser

Test different algorithms at ordering selection operators under conditions of uncertainity

Language: Java - Size: 26.4 KB - Last synced: 2 months ago - Pushed: almost 7 years ago - Stars: 0 - Forks: 0

sueszli/query-queen

postgres query execution plan analysis and benchmarking

Language: Jupyter Notebook - Size: 19.6 MB - Last synced: 24 days ago - Pushed: 2 months ago - Stars: 0 - Forks: 0

yizenov/este

Spanning Tree-based Query Plan Enumeration

Language: Python - Size: 1.9 MB - Last synced: 2 months ago - Pushed: 3 months ago - Stars: 0 - Forks: 0

kirillshevch/query_track

Find time-consuming database queries for ActiveRecord-based Rails Apps

Language: Ruby - Size: 326 KB - Last synced: 30 days ago - Pushed: 3 months ago - Stars: 290 - Forks: 14

abdallahalseddek/Javeats-Lites

Restaurant mangement system provides a powerful foundation for managing the various aspects of restaurant operations

Language: Java - Size: 45.9 MB - Last synced: 27 days ago - Pushed: about 1 month ago - Stars: 3 - Forks: 5

vagman/postgresql-query-optimization

Query optimization for database management systems class 2023-2024

Language: SQL - Size: 5.34 MB - Last synced: 2 months ago - Pushed: 2 months ago - Stars: 0 - Forks: 0

balsa-project/balsa

Balsa is a learned SQL query optimizer. It tailor optimizes your SQL queries to find the best execution plans for your hardware and engine.

Language: Python - Size: 29.1 MB - Last synced: 3 months ago - Pushed: almost 2 years ago - Stars: 105 - Forks: 19

KonstantinosPaschopoulos/Radix-Hash-Join

Implementation of the Radix Hash Join (RHJ) algorithm

Language: C - Size: 207 KB - Last synced: 4 months ago - Pushed: about 5 years ago - Stars: 2 - Forks: 0

MichaelMartinek/StructureGuidedTiDB

Source code associated with Master Thesis "Integration of Structure Guided Query Optimization into NewSQL Databases"

Language: Go - Size: 112 MB - Last synced: 4 months ago - Pushed: 4 months ago - Stars: 0 - Forks: 0

yizenov/l1-error

Sub-optimal Join Order Indicator

Language: Python - Size: 2.39 MB - Last synced: 4 months ago - Pushed: 4 months ago - Stars: 0 - Forks: 0

socialblue/laravel-query-adviser

With Laravel Query Adviser you can get more insights into the SQL queries created by Eloquent models used in your app. It logs the queries used by your application and provides a helpful overview of the SQL queries. You can rerun the SQL query to analyze the database impact or copy the SQL query to your clipboard.

Language: Vue - Size: 5.5 MB - Last synced: 13 days ago - Pushed: 5 months ago - Stars: 15 - Forks: 1

virajbhutada/Music-Store-SQL-Data-Analysis

Hands-on SQL data analysis project for music store. Enhance proficiency with database queries. Ideal for practitioners seeking real-world analytics experience. Gain insights into customer behavior, revenue trends, and genre preferences, empowering strategic decision-making in the music industry. Explore the project for a rich learning experience.

Size: 35.3 MB - Last synced: 2 months ago - Pushed: 2 months ago - Stars: 0 - Forks: 0

yizenov/compass_query_optimizer

The COMPASS Query Optimizer

Language: C++ - Size: 7.02 MB - Last synced: 4 months ago - Pushed: 4 months ago - Stars: 6 - Forks: 2

bvanhoekelen/performance

⏱ PHP performance tool analyser your script on time, memory usage and db query. Support Laravel and Composer for web, web console and command line interfaces.

Language: PHP - Size: 6.17 MB - Last synced: 5 months ago - Pushed: about 3 years ago - Stars: 520 - Forks: 37

hezuojiao/Joiner

Joiner is a research project for sql join order tuning using reinforcement learning algorithm.

Language: Python - Size: 180 KB - Last synced: 5 months ago - Pushed: over 5 years ago - Stars: 9 - Forks: 1

OnizukaLab/Scardina

Scalable Join Cardinality Estimaitor

Language: Python - Size: 384 KB - Last synced: 2 days ago - Pushed: 4 months ago - Stars: 4 - Forks: 2

Antonyfrtz/miniDB Fork of DataStories-UniPi/miniDB

An extremely minimal DB that can be used for educational purposes and rapid prototyping - Fork created by P20074,P20199,P20220

Language: Python - Size: 6.26 MB - Last synced: 26 days ago - Pushed: about 1 year ago - Stars: 0 - Forks: 1

Udrasht/SimpleRA

Data-Systems-Project || simplified relational database management system supporting only integer tables and matrices. Supports two-phase merge sort, buffer management and aggregate queries.

Language: C++ - Size: 8.44 MB - Last synced: 5 months ago - Pushed: 6 months ago - Stars: 1 - Forks: 0

abdallahalseddek/Practical-Web-Database-Design

Practical Web DataBase Design Book

Language: Python - Size: 2.24 MB - Last synced: 5 months ago - Pushed: 5 months ago - Stars: 1 - Forks: 0

P0bbn/1033-2020

A web-app hosted on AWS using a MySQL back-end database queried using dynamically generated, user-defined, complex SQL queries. Front-end user-interface designed using BootStrap.

Language: Jupyter Notebook - Size: 66.1 MB - Last synced: 6 months ago - Pushed: almost 2 years ago - Stars: 1 - Forks: 0

knagrecha/saturn

Saturn accelerates the training of large-scale deep learning models with a novel joint optimization approach.

Language: Python - Size: 107 KB - Last synced: 6 months ago - Pushed: 6 months ago - Stars: 78 - Forks: 4

berksudan/Data-Engineering-Case-Study-with-SQL-Optimization-and-Python-Data-Integration

Case Study for a data engineering job application at a company

Language: Python - Size: 3.51 MB - Last synced: 6 months ago - Pushed: 6 months ago - Stars: 0 - Forks: 0

kanmaytacker/fundamentals

A collection of tutorials on computer fundamentals

Language: Java - Size: 129 MB - Last synced: 6 months ago - Pushed: 7 months ago - Stars: 119 - Forks: 191

dagege/dagege.github.io

YongZhang's Page

Language: HTML - Size: 74.2 KB - Last synced: 7 months ago - Pushed: 7 months ago - Stars: 0 - Forks: 0

cosminTms/database-optimiser

Optimiser and Estimator classes for a Simple RDBMS

Language: Java - Size: 86.9 KB - Last synced: 7 months ago - Pushed: 7 months ago - Stars: 0 - Forks: 0

hbutani/spark-druid-olap 📦

Sparkline BI Accelerator provides fast ad-hoc query capability over Logical Cubes. This has been folded into our SNAP Platform(http://bit.ly/2oBJSpP) an Integrated BI platform on Apache Spark.

Language: Scala - Size: 127 MB - Last synced: 7 months ago - Pushed: almost 6 years ago - Stars: 286 - Forks: 96

KHvic/SPJ-Query-Engine

Database system built from scratch, Select-Project-Join Query Engine

Language: Java - Size: 657 KB - Last synced: 7 months ago - Pushed: about 7 years ago - Stars: 0 - Forks: 0

JoseGonzCSE/Database-Systems

Course Taken @ UCMerced [2022]

Language: Jupyter Notebook - Size: 25 MB - Last synced: 7 months ago - Pushed: 7 months ago - Stars: 0 - Forks: 0

tuannh982/query-planner-guide

write your own query planner

Language: Scala - Size: 3.37 MB - Last synced: 8 months ago - Pushed: 8 months ago - Stars: 0 - Forks: 0

for0nething/FACE-A-Normalizing-Flow-based-Cardinality-Estimator

A pytorch implementation for FACE: A Normalizing Flow based Cardinality Estimator

Language: Python - Size: 6.84 MB - Last synced: 7 months ago - Pushed: 8 months ago - Stars: 17 - Forks: 4

evgenabramov/MusicServiceDatabase

🎼 Проект по моделированию и реализации базы данных музыкального стримингового сервиса

Size: 11.3 MB - Last synced: 5 months ago - Pushed: about 4 years ago - Stars: 3 - Forks: 2

karam-mustafa/laravel-query-helper

Laravel package helps you to execute more effective databases queries, delete, update, insert, and optimize your database queries.

Language: PHP - Size: 148 KB - Last synced: 24 days ago - Pushed: over 2 years ago - Stars: 10 - Forks: 5

faizal108/RestAPI_Redis_caching_db

This project demonstrates the integration of Spring Boot with Redis caching to create a RESTful API for managing invoices. The application uses Redis as a caching mechanism to optimize database queries and improve performance when fetching and managing invoice records.

Language: Java - Size: 68.4 KB - Last synced: 9 months ago - Pushed: 9 months ago - Stars: 0 - Forks: 0

harvard-cns/cheetah-release

Cheetah is a system that optimizes queries using programmable switches.

Language: C - Size: 53.7 KB - Last synced: about 2 months ago - Pushed: almost 4 years ago - Stars: 18 - Forks: 3

PawSQL/pawsql.github.io.bk

PawSQL optimizes your SQL queries by rewriting your SQL queries, recommending optimal indexes in three steps.

Language: HTML - Size: 10.5 MB - Last synced: 9 months ago - Pushed: over 1 year ago - Stars: 3 - Forks: 1

eugene-khyst/postgresql-performance-essentials

PostgreSQL performance essentials in 1 hour

Size: 71.3 KB - Last synced: 9 months ago - Pushed: almost 2 years ago - Stars: 31 - Forks: 5

gabminamedez/STADVDB_S12.2_T120-21

A web application that aggregates and returns AirBnB data of New York City. In partial fulfillment of the course Advanced Database Systems (STADVDB) in De La Salle University-Manila.

Language: EJS - Size: 87.9 KB - Last synced: 9 months ago - Pushed: over 2 years ago - Stars: 0 - Forks: 0

mdarm/map-reduce-project

Project on MapReduce for the Μ111 - Big Data Management course, NKUA, Spring 2023.

Language: TeX - Size: 3.7 MB - Last synced: 10 months ago - Pushed: 10 months ago - Stars: 0 - Forks: 0

mohamadjavadx/FTS-Android-Implementation

full text search implementation on Android with Couchbase

Language: Kotlin - Size: 131 KB - Last synced: 10 months ago - Pushed: about 2 years ago - Stars: 3 - Forks: 1

gebenner1/CIS5500DatabaseWebsiteStocker

Stocker: A Stock Tracking and Related News Website based on a MySQL database, as well as using some NoSQL techniques.

Language: Jupyter Notebook - Size: 6.49 MB - Last synced: 12 months ago - Pushed: 12 months ago - Stars: 0 - Forks: 0

eugene-khyst/spring-data-examples 📦

Spring Data JPA, Spring Data JDBC, and Spring Data R2DBC examples and a comprehensive guide to JPA fetching and locking strategies.

Language: Java - Size: 3.46 MB - Last synced: 9 months ago - Pushed: almost 2 years ago - Stars: 93 - Forks: 41

skth5199/query-optimiser

Query Optimiser built for SJDB

Language: Java - Size: 42 KB - Last synced: 12 months ago - Pushed: about 2 years ago - Stars: 1 - Forks: 0

fukien/carrot

Autumn 2017. A simple implementation of relational database with query optimization as the course project of Principles and Design of Database System, Renmin University of China.

Language: C++ - Size: 20.7 MB - Last synced: 12 months ago - Pushed: over 3 years ago - Stars: 17 - Forks: 6

TangSiyang2001/RookieDB

A personal implementation of Berkley's CS186.

Language: Java - Size: 688 KB - Last synced: about 1 year ago - Pushed: about 1 year ago - Stars: 1 - Forks: 0

Hussein-Fadl/cs422-execution-models

This project was a part of the CS422 - Database Systems course offered at EPFL (Spring 2022)

Language: Scala - Size: 37.1 KB - Last synced: about 1 year ago - Pushed: about 1 year ago - Stars: 0 - Forks: 0

nightvisi0n/pg-formatter-ts

Format PostgreSQL SQL with ease using this TypeScript library, which provides a convenient API wrapping the `pgFormatter` CLI tool

Language: TypeScript - Size: 205 KB - Last synced: 9 days ago - Pushed: about 1 year ago - Stars: 1 - Forks: 0

asolimando/xqueryprojector

XQuery query processing optimization based on XML projection

Language: HTML - Size: 15.3 MB - Last synced: about 1 year ago - Pushed: over 6 years ago - Stars: 1 - Forks: 0

thu-west/FBRW

Implementation of our paper "An Efficient Approximate Algorithm for Single-Source Discounted Hitting Time Query" (DASFAA2020)

Language: C++ - Size: 64.5 KB - Last synced: about 1 year ago - Pushed: over 2 years ago - Stars: 1 - Forks: 0

neurocard/neurocard

State-of-the-art neural cardinality estimators for join queries

Language: Python - Size: 52.2 MB - Last synced: about 1 year ago - Pushed: over 3 years ago - Stars: 51 - Forks: 18

mu-majid/sql-postgres-lab

Using PostgresSQL to store and fetch data, tune queries, and design efficient database structures!

Language: JavaScript - Size: 11.5 MB - Last synced: about 1 year ago - Pushed: about 3 years ago - Stars: 8 - Forks: 1

ZhengtongYan/query-optimizer-lib Fork of itrummer/query-optimizer-lib

Contains implementations of various algorithms for database query optimization. The algorithms cover multiple problem variants (e.g., traditional and multi-objective query optimization) and offer different tradeoffs between optimality guarantees and optimization time (e.g., fast randomized algorithms, approximation schemes, exhaustive algorithms, parallel algorithms, ...).

Size: 130 KB - Last synced: 11 months ago - Pushed: over 7 years ago - Stars: 2 - Forks: 0

naru-project/naru

Neural Relation Understanding: neural cardinality estimators for tabular data

Language: Python - Size: 54.7 KB - Last synced: about 1 year ago - Pushed: almost 3 years ago - Stars: 76 - Forks: 25

SauzeauYannis/BDD-Projet 📦

An Oracle Database Project

Size: 1.87 MB - Last synced: about 1 year ago - Pushed: almost 3 years ago - Stars: 0 - Forks: 0

Etshawy1/Database-Tuning

💻🛠 Database Tuning, Optimization & performance analysis.

Language: JavaScript - Size: 5.64 MB - Last synced: about 1 year ago - Pushed: over 2 years ago - Stars: 5 - Forks: 1

jaregauri/olympics_dashboard

Olympics Dashboard is a database management project which aims at providing a platform about how the Olympics has evolved over time, participation, and performance rate based on gender, different countries, different sport and sports events. A lot of data is generated and collected each year at the Olympics which calls for a method to bring out more meaning from the data. A visualization-based approach has been taken in this project in that direction. A dashboard is proposed based on a historical dataset on the modern Olympic Games, including all the Games from Athens 1896 to Rio 2016.

Language: Python - Size: 3.89 MB - Last synced: about 1 year ago - Pushed: over 2 years ago - Stars: 2 - Forks: 1

tommenx/DDB

基于MySQL的分布式数据库

Language: C++ - Size: 16.6 MB - Last synced: about 1 year ago - Pushed: over 5 years ago - Stars: 16 - Forks: 0

meylism/sparser

A library that accelerates parsing

Language: Java - Size: 111 KB - Last synced: about 1 year ago - Pushed: over 1 year ago - Stars: 0 - Forks: 0

jamadaha/P6 📦

Query estimation for SQL queries

Language: C# - Size: 3.51 MB - Last synced: 4 months ago - Pushed: almost 2 years ago - Stars: 1 - Forks: 1

waltercai/pqo-opensource

Language: C - Size: 30.8 MB - Last synced: about 1 year ago - Pushed: almost 3 years ago - Stars: 20 - Forks: 5

mantask/thesis-wrapper

An experimental setup for my master thesis "Optimizing web extraction queries for robustness"

Language: HTML - Size: 552 KB - Last synced: about 1 year ago - Pushed: over 1 year ago - Stars: 1 - Forks: 0

nicolasmelo1/PyQuery

Why did i do this?

Language: Python - Size: 24.4 KB - Last synced: about 1 year ago - Pushed: almost 3 years ago - Stars: 5 - Forks: 1

Asoke26/Simpli-Squared

Simpli-Squared is a statistics-free join ordering algorithm Without Cardinality Estimates.

Language: Python - Size: 171 KB - Last synced: about 1 year ago - Pushed: over 2 years ago - Stars: 3 - Forks: 0

AshirwadPradhan/tpsql

Asynchronous execution of parallely executing SQL query

Language: Python - Size: 570 KB - Last synced: about 1 year ago - Pushed: about 1 year ago - Stars: 2 - Forks: 0

Aboda81/Query-Analysis-and-Optmization

Report for 12 SQL queries using Postgres analysis and writing new equivalent queries and analyzing performance

Size: 3.76 MB - Last synced: about 1 year ago - Pushed: almost 2 years ago - Stars: 0 - Forks: 0

ZhengtongYan/Query-Optimization-TUM-IN2219 Fork of durner/Query-Optimization-TUM-IN2219

Homework for Query Optimization - a TUM Computer Science Course

Size: 1.87 MB - Last synced: 11 months ago - Pushed: over 7 years ago - Stars: 0 - Forks: 0

Kashif-Rabbani/sparql-optimization

A research paper published in EDBT-2021 titled as "Optimizing SPARQL Queries using Shape Statistics"

Language: Java - Size: 72.1 MB - Last synced: about 1 year ago - Pushed: over 2 years ago - Stars: 0 - Forks: 0

motapinto/sql-query-optimization

SQL: Query optimization

Size: 10.9 MB - Last synced: about 1 year ago - Pushed: about 3 years ago - Stars: 1 - Forks: 0

Vrroom/parallel-qo-postgres

(not) Parellel Query Optimizer for Postgres. In this fork of Postgres, we replace the original query optimizer with a parallelized query optimizer based on the work of Trummer et al.

Language: C - Size: 274 MB - Last synced: about 1 year ago - Pushed: about 3 years ago - Stars: 4 - Forks: 2

michpara/CSI3130-Databases-II

Labs for Databases II

Language: C - Size: 127 KB - Last synced: about 1 year ago - Pushed: over 3 years ago - Stars: 0 - Forks: 0

adhiiisetiawan/query-optimization-sqlite

Code for query optimization in SQLite

Language: Java - Size: 215 KB - Last synced: about 1 year ago - Pushed: almost 4 years ago - Stars: 0 - Forks: 0

SDM-TIB/Ontario-SEAData2020

Optimizing Federated Queries Based on the Physical Design of a Data Lake

Language: Python - Size: 530 MB - Last synced: about 1 year ago - Pushed: almost 2 years ago - Stars: 0 - Forks: 0

kyleruss/cablecity-db-optimization

PL/SQL Query and structure optimizations

Size: 788 KB - Last synced: 4 months ago - Pushed: about 5 years ago - Stars: 0 - Forks: 0

mantask/thesis-report

A master thesis report "Optimizing Web Extraction Queries For Robustness"

Language: TeX - Size: 1.98 MB - Last synced: about 1 year ago - Pushed: almost 5 years ago - Stars: 0 - Forks: 0

funbringer/pg_pathman Fork of postgrespro/pg_pathman

Partitioning tool for PostgreSQL

Language: C - Size: 3.78 MB - Last synced: 11 months ago - Pushed: over 5 years ago - Stars: 0 - Forks: 0

Related Keywords
query-optimization 88 database 26 sql 23 postgresql 17 mysql 9 cardinality-estimation 6 database-design 5 python 5 indexing 4 learned-database 4 relational-databases 4 laravel 4 databases 4 postgres 4 query-optimizer 4 deep-generative-model 3 query-planning 3 java 3 query 3 query-plan 3 distributed-systems 3 performance 3 optimization 3 partitioning 3 query-engine 3 performance-analysis 3 deep-learning 2 recovery 2 pytorch 2 sqlite 2 btree-indexes 2 sql-queries 2 concurrency-control 2 plsql 2 oracle-database 2 data-science 2 django 2 knowledge-graph 2 transformers 2 database-management 2 self-supervised-learning 2 android 2 query-builder 2 spark-sql 2 php 2 query-language 2 deep-web 2 master-thesis 2 robustness 2 hibernate 2 hash-indexes 2 ai 2 mysql-database 2 nlp 2 unsupervised-learning 2 query-analysis 2 normalization 2 learned-database-components 2 density-estimation 2 postgresql-database 2 fdw 2 hash 2 partition-table 2 query-processing 2 pathman 2 range 2 testing 2 transaction-processing 2 query-planner 2 spring-boot 2 currency 1 iterator-execution-model 1 entity-graph 1 entity 1 dms 1 column-at-a-time-execution 1 criteria-api 1 bplus-tree 1 jpa 1 dbms-project 1 database-implementation 1 jpql 1 locking-strategies 1 optimistic-locking 1 spring-data-r2dbc 1 spring-data-jpa 1 spring-data-jdbc 1 spring-data 1 programmable-network 1 index-tuning 1 pawsql 1 sql-tuning 1 bitmap-scans 1 database-perfomance 1 gin-indexes 1 hash-join 1 index-scan 1 merge-join 1 multicolumn-indexes 1 nested-loops 1