Build a Real-time Analytics Application With TiDB

Disclaimer: PingExpress_DemoCorp is a dummy company. It does NOT reflect or imply any real company. This tutorial is for demonstration purposes only. Do NOT use any material (including but not limited to code and commands) from this tutorial in production environments. PingExpress_DemoCorp is a supply chain management company in the United States. With more people … Read more

How to Build Spark Lineage for Data Lakes

When a data pipeline breaks, data engineers need to immediately understand where the rupture occurred and what has been impacted. Data downtime is costly. Without data lineage—a map of how assets are connected and data moves across its lifecycle—data engineers might as well conduct their incident triage and root cause blindfolded analysis. Developing data lineage … Read more

Spark-Radiant: Spark Performance, Cost Optimizer

Spark-Radiant is Apache Spark Performance and Cost Optimizer. Spark-Radiant will help optimize performance and cost considering catalyst optimizer rules, enhance auto-scaling in Spark, collect important metrics related to a Spark job, Bloom filter index in Spark, etc. Spark-Radiant is now available and ready to use. The dependency for Spark-Radiant 1.0.4 is available in Maven central. … Read more

CockroachDB, Deno: Combining Technologies – DZone Web Dev

This tutorial will walk through building a simple application using Deno, backed by CockroachDB (CRDB) Serverless. Deno (pronounced dee-no) is a “modern runtime environment for JavaScript and TypeScript”, while CockroachDB Serverless offers a free startup that scales with your app. Both technologies claim quick startup times for developers, so I’d like to test them out … Read more

sql server – Optimizing MySQL query with INNER JOINS, LEFT JOINS, GROUP BY and HAVING

I’m having trouble optimizing this really big query and I can’t change the table structure except creating additional indexes and small adjustments. SELECT ‘Fattura Prodotti Postali’ AS `type`, SUM(dpd.qta) AS `products_count_quantity`, COUNT(dpd.IDlavorazione_dett) AS `products_count`, dpd.IDlavorazione_dett AS `IDlavorazione_dett`, dp.prod_totali- CAST(dp.opzione1 AS UNSIGNED) AS `process_products_count`, dp.IDdistinta AS `product_code`, dp.data_distinta AS `process_date`, dp.IDesito AS `process_status_id`, dp.note AS `process_note`, … Read more

sql server – SQLLocalDB doesn’t start

SQLLocalDB doesn’t start and throws an error as below. C:Windowssystem32>sqllocaldb c MSSQLLocalDB Creation of LocalDB instance “MSSQLLocalDB” failed because of the following error: Error occurred during LocalDB instance startup: SQL Server process failed to start. Note: Command started with Run as Administrator. Event viewer shows below log: Windows API call WaitForMultipleObjects returned error code: 575. … Read more

Migrating from Sakila-MySQL to Couchbase, Part 5

With the release of 7.1, Couchbase N1QL adds support for JavaScript user-defined functions. Originally as seen in Part2: Views and UDFs and Part3: Stored Procedures, we used N1QL UDFs to map the MySQL UDFs and stored procedures. With N1QL UDFs, we can do only a single query or operation per function. This meant our translation … Read more

Querydsl vs. JPA Criteria – Introduction

I’ve used JPA Criteria for many years. The main advantage is its type-safe approach (compared to JPQL), but the code is quite complicated and not always straightforward. Recently, I came across a Querydsl framework and I saw its benefits immediately. The main benefits for me are: Type-safe approach. Fluent API with SQL style – the … Read more