vinothchandar commented on code in PR #19268:
URL: https://github.com/apache/hudi/pull/19268#discussion_r3567899454
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website/blog/2025-04-02-secondary-index.md:
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@@ -193,4 +201,14 @@ Indexing has been a core component of Apache Hudi since
its inception, enabling
Additionally, to ensure that index maintenance does not introduce bottlenecks,
Hudi’s *asynchronous indexing* service decouples index updates from ingestion,
enabling seamless scaling while keeping indexes timeline-consistent and
ACID-compliant. These advancements further solidify Hudi’s role as a
high-performance lakehouse platform, making data structures such as secondary
indexes more accessible.
----
\ No newline at end of file
+---
+
+## FAQ
+
+<PostFAQ heading={null} items={[
+ {question: 'What is a secondary index in Apache Hudi?', answer: 'A secondary
index, introduced in Hudi 1.0, lets users index columns that are not part of
the record key. Hudi stores mappings between secondary key values and record
keys in its metadata table, so queries filtering on non-primary-key fields can
prune files via data skipping instead of scanning the full table.'},
+ {question: 'How do I create a secondary index in Hudi?', answer: 'On a table
with the record index enabled, run a SQL statement such as CREATE INDEX
idx_city ON hudi_table(city). Secondary indexes can also be configured through
the Spark DataSource API using hoodie.metadata.index.secondary.enable and
hoodie.datasource.write.secondarykey.column.'},
+ {question: 'How much does a secondary index improve query performance?',
answer: 'In a TPCDS 1TB benchmark with an index on the web_sales table, the
same join query ran about 33% faster on the first run and 58% faster on the
second, while the data scanned dropped by roughly 90%, from 67GB across 5000
files to 7GB across 521 files.'},
+ {question: 'Which query engines support Hudi secondary indexes?', answer:
'In Hudi 1.0, secondary indexes are supported in Apache Spark, with support for
Flink, Presto, and Trino planned for Hudi 1.1. Reduced data scans particularly
benefit cloud query engines like AWS Athena that price by data scanned.'},
Review Comment:
i think Trino can already do SI reads. So we should incorporate that? Spark.
Trino should be able to do SI reads?
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