Query Acceleration

📄️ View Running Queries

This article describes how to view running queries in StarRocks and analyze their resource consumption.

This topic describes the basic concept of StarRocks cost-based optimizer (CBO) and how to collect statistics for the CBO to select an optimal query plan. StarRocks 2.4 introduces histograms to gather accurate data distribution statistics.

📄️ Query Feedback

This topic introduces the Query Feedback feature, its application scenarios, and how to optimize query plans based on feedback from execution statistics using Query Plan Advisor.

📄️ Synchronous materialized view

This topic describes how to create, use, and manage a synchronous materialized view (Rollup).

🗃️ Asynchronous materialized views

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📄️ Colocate Join

For shuffle join and broadcast join, if the join condition is met, the data rows of the two joining tables are merged into a single node to complete the join. Neither of these two join methods can avoid latency or overhead caused by data network transmission between nodes.

📄️ Use Lateral Join for column-to-row conversion

Column-to-row conversion is a common operation in ETL processing. Lateral is a special Join keyword that can associate a row with an internal subquery or table function. By using Lateral in conjunction with unnest(), you can expand one row into multiple rows. For more information, see unnest.

🗃️ Caching

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🗃️ Computing the number of distinct values

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📄️ Sorted streaming aggregate

Common aggregation methods in database systems include hash aggregate and sort aggregate.

📄️ Accelerate COUNT(DISTINCT) and Joins with AUTO INCREMENT and Global Dictionary

This topic describes how to accelerate COUNT(DISTINCT) calculation and Joins using AUTO INCREMENT columns and Global Dictionary.

📄️ Flat JSON

This article introduces the basic concept of Flat JSON and how to use this feature.

📄️ Accelerate Cardinality-Preserving Joins

This topic describes how to accelerate cardinality-preserving joins with table pruning. This feature is supported from v3.1 onwards.

📄️ JIT Compilation for Expressions

This topic describes how to enable and configure JIT compilation for expressions in StarRocks.