Tagged articles

419 articles

Page 5 of 5

Feb 21, 2016 · Databases

Boost Oracle Distributed Query Performance with Collocated Inline Views and Hints

This article explains how to optimize Oracle distributed queries that involve remote tables by minimizing remote calls, reducing result set size, and improving execution plans through techniques such as collocated inline views, CBO behavior, and driving_site hints, illustrated with detailed examples and performance measurements.

Collocated ViewDatabase PerformanceDistributed Query

0 likes · 11 min read

Boost Oracle Distributed Query Performance with Collocated Inline Views and Hints

dbaplus Community

Dec 19, 2015 · Databases

Unlocking MySQL Query Cache: How It Works, Tuning Tips, and Real‑World Experiments

This article explains MySQL's query cache mechanism, covering its workflow, configuration parameters, cache‑management commands, internal data structures, experimental verification steps, and practical recommendations for when to enable or disable the feature.

Cache TuningDatabase PerformanceFree Block Management

0 likes · 15 min read

Unlocking MySQL Query Cache: How It Works, Tuning Tips, and Real‑World Experiments

dbaplus Community

Nov 29, 2015 · Databases

Uncovering Hidden PostgreSQL Lock Requests: Why Implicit Locks Cause Unexpected Waits

This article explains how implicit lock requests in PostgreSQL can lead to surprising lock waits, demonstrates debugging steps with lock_debug and a reporting script, and offers practical tips like lock_timeout and statement_timeout to prevent prolonged blocking scenarios.

Database PerformanceDebuggingPostgreSQL

0 likes · 6 min read

Uncovering Hidden PostgreSQL Lock Requests: Why Implicit Locks Cause Unexpected Waits

dbaplus Community

Nov 25, 2015 · Databases

Unlock Oracle SQL Monitor: Free Tool for Powerful SQL Optimization

This guide explains how to access and use Oracle SQL Monitor—a free feature in Oracle Enterprise Edition—to capture SQL execution details, analyze performance bottlenecks, compare estimated and actual rows, and apply targeted optimizations using both the EM console and command‑line scripts.

Database PerformanceOracleSQL Monitor

0 likes · 9 min read

Unlock Oracle SQL Monitor: Free Tool for Powerful SQL Optimization

dbaplus Community

Nov 18, 2015 · Databases

Demystifying DB2 Optimizer: How Cost Models Shape Query Performance

This article explains the inner workings of the DB2 optimizer, its four-step processing flow, cost‑based decision making, and detailed examples comparing full‑table and index scans, followed by practical tuning tips and a Q&A session for real‑world query optimization.

Cost ModelDB2Database Performance

0 likes · 19 min read

Demystifying DB2 Optimizer: How Cost Models Shape Query Performance

dbaplus Community

Nov 12, 2015 · Databases

Mastering MySQL View Optimization: Techniques, Limits, and Best Practices

This article explains how MySQL versions up to 5.5 process and optimize views, outlines the exact conditions required for view merge rewriting, compares derived table handling with the SQL standard, and provides concrete test cases to illustrate performance pitfalls.

Database PerformanceDerived TablesSQL

0 likes · 6 min read

Mastering MySQL View Optimization: Techniques, Limits, and Best Practices

dbaplus Community

Oct 21, 2015 · Databases

Why Oracle RAC Queries Fail with ORA-04030 on AIX: The Hidden Shell Limits Issue

An Oracle RAC 11g installation on AIX failed intermittent queries with ORA‑04030 errors, and a deep dive revealed that missing shell limits for the grid user capped process memory at 128 MB, causing PGA allocation failures despite ample system resources.

AIXDatabase PerformanceORA-04030

0 likes · 10 min read

Why Oracle RAC Queries Fail with ORA-04030 on AIX: The Hidden Shell Limits Issue

Java High-Performance Architecture

Oct 19, 2015 · Databases

Why MySQL Query Cache Fails: 10 Common Scenarios Explained

This article explains how MySQL's query cache works, why it uses the full SQL statement as a key, and lists ten typical situations—such as using SQL_NO_CACHE, volatile functions, or locks—that prevent a query from being cached.

Database PerformanceSQLmysql

0 likes · 2 min read

Why MySQL Query Cache Fails: 10 Common Scenarios Explained

Architect

Sep 18, 2015 · Databases

Implementing Asynchronous MySQL Queries in PHP Using Coroutines

This article explains how to achieve asynchronous MySQL queries in PHP by leveraging mysqlnd's async functions and PHP generators, compares synchronous and asynchronous execution times, provides a complete coroutine‑based example, and discusses performance considerations and limitations.

AsynchronousCoroutinesDatabase Performance

0 likes · 7 min read

Implementing Asynchronous MySQL Queries in PHP Using Coroutines

Efficient Ops

Aug 26, 2015 · Databases

Why Is MySQL’s Version Evolution So Slow? Expert Insights on China’s Database Landscape

In this expert Q&A, two leading Chinese database specialists discuss why MySQL’s major releases lag behind Oracle’s, examine the influence of Alibaba on MySQL’s domestic growth, and explore the broader implications for the Chinese open‑source database ecosystem.

Chinese Tech IndustryDatabase PerformanceDatabase Versioning

0 likes · 9 min read

Why Is MySQL’s Version Evolution So Slow? Expert Insights on China’s Database Landscape

Java High-Performance Architecture

Aug 3, 2015 · Databases

How MySQL’s Query Cache Works: Inside the Hash‑Based Mechanism

MySQL’s Query Cache stores the results of SELECT statements by hashing the query, keeping the result set in memory, and invalidating cached entries whenever related tables change, allowing identical queries to be served instantly without re‑execution.

Database PerformanceHashingSQL

0 likes · 2 min read

How MySQL’s Query Cache Works: Inside the Hash‑Based Mechanism

Java High-Performance Architecture

Jul 27, 2015 · Databases

How to Minimize Nested Loop Overhead in SQL Joins for Faster Queries

Learn practical techniques to reduce nested loop iterations, prioritize inner-loop optimization, ensure join columns are indexed, and configure join buffers effectively, so your SQL joins run with minimal resource consumption and maximum performance.

Database PerformanceJOIN optimizationNested Loop

0 likes · 3 min read

How to Minimize Nested Loop Overhead in SQL Joins for Faster Queries

Java High-Performance Architecture

Jul 26, 2015 · Databases

Understanding MySQL’s Nested Loop Join: How It Works and Why Indexes Matter

MySQL uses only the Nested Loop Join algorithm, iterating each row of the left table and comparing it with every row of the right table, and when multiple tables are involved the intermediate results are repeatedly joined, making proper indexing crucial for performance.

Database PerformanceNested Loop JoinSQL

0 likes · 3 min read

Understanding MySQL’s Nested Loop Join: How It Works and Why Indexes Matter

Efficient Ops

Jul 24, 2015 · Databases

What MySQL 5.7 InnoDB Experts Reveal: Key Q&A on New Features

An expert panel from the High‑Efficiency Operations community answers eleven pressing MySQL 5.7 questions, covering test hardware, GA timeline, GIS speed, virtual column indexing, materialized view plans, 2‑D geo support, performance monitoring, Oracle’s market strategy, geojson handling, multi‑source replication, buffer‑pool locking, and InnoDB Memcached consistency.

Database PerformanceGISInnoDB

0 likes · 7 min read

What MySQL 5.7 InnoDB Experts Reveal: Key Q&A on New Features

Qunar Tech Salon

May 3, 2015 · Databases

Optimizing PostgreSQL Queries for Flight Data Retrieval at Qunar

The article analyzes a slow PostgreSQL query that joins multiple tables to fetch flight numbers, compares several alternative query formulations with their execution plans, and presents a final solution using array aggregation to achieve sub‑millisecond performance despite existing indexes.

Database PerformancePostgreSQLSQL

0 likes · 7 min read

Optimizing PostgreSQL Queries for Flight Data Retrieval at Qunar

MaGe Linux Operations

Jan 13, 2015 · Databases

Can TokuDB Really Cut Storage by 14× and Boost Inserts? Real‑World Test Results

This article presents a practical performance comparison between TokuDB and InnoDB, covering compression ratio, insert speed, online DDL operations, CPU usage, IOPS, and response time, and concludes with the advantages and drawbacks of adopting TokuDB in production.

Database PerformanceInsert SpeedOnline DDL

0 likes · 7 min read

Can TokuDB Really Cut Storage by 14× and Boost Inserts? Real‑World Test Results

ITPUB

Aug 28, 2014 · Databases

How Oracle DBAs Tackle Performance: Real‑World Stats Tuning and Career Insights

In this interview, veteran Oracle DBA Shi Yuedong shares his career journey, personal philosophy on opportunity, a hands‑on performance‑diagnosis case at Lenovo, experiments revealing Oracle 12.1's default statistics sampling rate, and thoughtful perspectives on big data versus data‑warehouse evolution.

DBAData WarehouseDatabase Performance

0 likes · 18 min read

How Oracle DBAs Tackle Performance: Real‑World Stats Tuning and Career Insights

MaGe Linux Operations

Jul 3, 2014 · Databases

MySQL Partition vs. Sharding: When to Use Each and How They Differ

This article explains what MySQL table partitioning and sharding (splitting tables) are, compares their implementation, data handling, performance impact, and difficulty, and shows how they can complement each other for high‑traffic, large‑data scenarios.

Database PerformancePartitioningScalability

0 likes · 6 min read

MySQL Partition vs. Sharding: When to Use Each and How They Differ

MaGe Linux Operations

Jun 23, 2014 · Databases

How a Simple Diagnostic Box Can Reveal and Fix Slow Database Queries

By adding a lightweight diagnostic box that displays each page’s database query count and total execution time, developers can quickly spot inefficient queries, compare development and production performance, and make informed optimizations, ultimately improving website speed and reliability.

Database PerformanceSQL queriesWeb Optimization

0 likes · 5 min read

How a Simple Diagnostic Box Can Reveal and Fix Slow Database Queries