Hyperspace for Delta Lake

The Parquet format is one of the most widely used columnar storage formats in the Spark ecosystem. Given that I/O is expensive and that the storage layer is the entry point for any query execution, understanding the intricacies of your storage format is important for optimizing your workloads. As an introduction, we will provide context around the format, covering the basics of structured data formats and the underlying physical data storage model alternatives (row-wise, columnar and hybrid). Given this context, we will dive deeper into specifics of the Parquet format: representation on disk, physical data organization (row-groups, column-chunks and pages) and encoding schemes. Now equipped with sufficient background knowledge, we will discuss several performance optimization opportunities with respect to the format: dictionary encoding, page compression, predicate pushdown (min/max skipping), dictionary filtering and partitioning schemes. We will learn how to combat the evil that is ‘many small files’, and will discuss the open-source Delta Lake format in relation to this and Parquet in general. This talk serves both as an approachable refresher on columnar storage as well as a guide on how to leverage the Parquet format for speeding up analytical workloads in Spark using tangible tips and tricks.

This document describes the Delta architecture, which unifies batch and streaming data processing. Delta achieves this through a continuous data flow model using structured streaming. It allows data engineers to read consistent data while being written, incrementally read large tables at scale, rollback in case of errors, replay and process historical data along with new data, and handle late arriving data without delays. Delta uses transaction logging, optimistic concurrency, and Spark to scale metadata handling for large tables. This provides a simplified solution to common challenges data engineers face.

There are a growing set of optimization mechanisms that allow you to achieve competitive SQL performance. Spark has extension points that help third parties to add customizations and optimizations without needing these optimizations to be merged into Apache Spark. This is very powerful and helps extensibility. We have added some enhancements to the existing extension points framework to enable some fine grained control. This talk will be a deep dive at the extension points that is available in Spark today. We will also talk about the enhancements to this API that we developed to help make this API more powerful. This talk will be of benefit to developers who are looking to customize Spark in their deployments.

Spark SQL is a highly scalable and efficient relational processing engine with ease-to-use APIs and mid-query fault tolerance. It is a core module of Apache Spark. Spark SQL can process, integrate and analyze the data from diverse data sources (e.g., Hive, Cassandra, Kafka and Oracle) and file formats (e.g., Parquet, ORC, CSV, and JSON). This talk will dive into the technical details of SparkSQL spanning the entire lifecycle of a query execution. The audience will get a deeper understanding of Spark SQL and understand how to tune Spark SQL performance.

Recently, a set of modern table formats such as Delta Lake, Hudi, Iceberg spring out. Along with Hive Metastore these table formats are trying to solve problems that stand in traditional data lake for a long time with their declared features like ACID, schema evolution, upsert, time travel, incremental consumption etc.

Parquet performance tuning focuses on optimizing Parquet reads by leveraging columnar organization, encoding, and filtering techniques. Statistics and dictionary filtering can eliminate unnecessary data reads by filtering at the row group and page levels. However, these optimizations require columns to be sorted and fully dictionary encoded within files. Increasing dictionary size thresholds and decreasing row group sizes can help avoid dictionary encoding fallback and improve filtering effectiveness. Future work may include new encodings, compression algorithms like Brotli, and page-level filtering in the Parquet format.

"The common use cases of Spark SQL include ad hoc analysis, logical warehouse, query federation, and ETL processing. Spark SQL also powers the other Spark libraries, including structured streaming for stream processing, MLlib for machine learning, and GraphFrame for graph-parallel computation. For boosting the speed of your Spark applications, you can perform the optimization efforts on the queries prior employing to the production systems. Spark query plans and Spark UIs provide you insight on the performance of your queries. This talk discloses how to read and tune the query plans for enhanced performance. It will also cover the major related features in the recent and upcoming releases of Apache Spark. "

Apache Spark continues to grow in popularity - due to advanced analytics/machine learning, high performance processing, real-time streaming and multiple language support. Big Data technology is adding more data processing options to an already long list of legacy databases and file systems. As a result, enterprises continue to look for effective and approachable ways to federate all these data sources to solve business information needs. One under-appreciated feature of Spark is its ability to help quickly and powerfully enable federated data access. This presentation will discuss and demonstrate using Spark to query/combine multiple disparate data sources. We will see how to access the various data sources from Spark, normalize to Spark RDDs and combine for processing. The demo will show combining sources such as HDFS, JSON files, HBase, Hive and PostgreSQL and write the result back to a Data Mart for analysis. Also we will show the use of SparkSQL to access federated data in Spark through the Spark Thrift Server using the the Tableau BI tool.

This document discusses Delta Change Data Feed (CDF), which allows capturing changes made to Delta tables. It describes how CDF works by storing change events like inserts, updates and deletes. It also outlines how CDF can be used to improve ETL pipelines, unify batch and streaming workflows, and meet regulatory needs. The document provides examples of enabling CDF, querying change data and storing the change events. It concludes by offering a demo of CDF in Jupyter notebooks.

The document discusses updates to InfluxDB IOx, a new columnar time series database. It covers changes and improvements to the API, CLI, query capabilities, and path to open sourcing builds. Key points include moving to gRPC for management, adding PostgreSQL string functions to queries, optimizing functions for scalar values and columns, and monitoring internal systems as the first step to releasing open source builds.

Talk from Dremio's Subsurface conference on March 3, 2022. Discusses applications of Arrow and Voltron Data's new Enterprise Subscription offering

Spark SQL works very well with structured row-based data. Vectorized reader and writer for parquet/orc can make I/O much faster. It also used WholeStageCodeGen to improve the performance by Java JIT code. However Java JIT is usually not working very well on utilizing latest SIMD instructions under complicated queries. Apache Arrow provides columnar in-memory layout and SIMD optimized kernels as well as a LLVM based SQL engine Gandiva. These native based libraries can accelerate Spark SQL by reduce the CPU usage for both I/O and execution.

At Adobe Experience Platform, we ingest TBs of data every day and manage PBs of data for our customers as part of the Unified Profile Offering. At the heart of this is a bunch of complex ingestion of a mix of normalized and denormalized data with various linkage scenarios power by a central Identity Linking Graph. This helps power various marketing scenarios that are activated in multiple platforms and channels like email, advertisements etc. We will go over how we built a cost effective and scalable data pipeline using Apache Spark and Delta Lake and share our experiences. What are we storing? Multi Source – Multi Channel Problem Data Representation and Nested Schema Evolution Performance Trade Offs with Various formats Go over anti-patterns used (String FTW) Data Manipulation using UDFs Writer Worries and How to Wipe them Away Staging Tables FTW Datalake Replication Lag Tracking Performance Time!

Apache Hudi is an open data lake platform, designed around the streaming data model. At its core, Hudi provides a transactions, upserts, deletes on data lake storage, while also enabling CDC capabilities. Hudi also provides a coherent set of table services, which can clean, compact, cluster and optimize storage layout for better query performance. Finally, Hudi's data services provide out-of-box support for streaming data from event systems into lake storage in near real-time. In this talk, we will walk through an end-end use case for change data capture from a relational database, starting with capture changes using the Pulsar CDC connector and then demonstrate how you can use the Hudi deltastreamer tool to then apply these changes into a table on the data lake. We will discuss various tips to operationalizing and monitoring such pipelines. We will conclude with some guidance on future integrations between the two projects including a native Hudi/Pulsar connector and Hudi tiered storage.

Hive tables are an integral part of the big data ecosystem, but the simple directory-based design that made them ubiquitous is increasingly problematic. Netflix uses tables backed by S3 that, like other object stores, don’t fit this directory-based model: listings are much slower, renames are not atomic, and results are eventually consistent. Even tables in HDFS are problematic at scale, and reliable query behavior requires readers to acquire locks and wait. Owen O’Malley and Ryan Blue offer an overview of Iceberg, a new open source project that defines a new table layout addresses the challenges of current Hive tables, with properties specifically designed for cloud object stores, such as S3. Iceberg is an Apache-licensed open source project. It specifies the portable table format and standardizes many important features, including: * All reads use snapshot isolation without locking. * No directory listings are required for query planning. * Files can be added, removed, or replaced atomically. * Full schema evolution supports changes in the table over time. * Partitioning evolution enables changes to the physical layout without breaking existing queries. * Data files are stored as Avro, ORC, or Parquet. * Support for Spark, Pig, and Presto.