How to CREATE INDEX in BigQuery

How do I create an index in BigQuery to speed up queries?

CREATE INDEX builds a secondary index on one or more table columns to speed up point lookup and range queries in BigQuery.

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Description

Example H2

Example H3

Why use CREATE INDEX in BigQuery?

Indexes let BigQuery skip full table scans for highly selective filters, reducing scan costs and latency on large tables.

What types of indexes can I create?

BigQuery currently supports SEARCH indexes for equality, range, and phrase matching on STRING, INT64, NUMERIC, and TIMESTAMP columns.

How do I create a simple index?

Use CREATE SEARCH INDEX followed by the index name, target table, and column list.Add IF NOT EXISTS to avoid errors if the index already exists.

How do I create a composite index?

List multiple columns inside the parentheses in the order you want them indexed. BigQuery optimizes queries that match the leading columns of the index.

Can I specify index options?

Yes. Use the OPTIONS clause to set properties such as field_length or include_null_keys.

What is the effect on storage and cost?

Indexes consume extra storage—roughly 20–30% of the indexed data size.Query costs may drop, but storage costs increase.

How do I drop or rebuild an index?

Use DROP SEARCH INDEX index_name to remove it. Re-create to rebuild. BigQuery handles locking transparently.

Best practices for CREATE INDEX

Create indexes only on columns used frequently in selective predicates. Avoid indexing high-cardinality JSON fields until needed.Monitor EXPLAIN plans to confirm index usage.

Example: speeding up customer lookups

The query section below shows how an index on Orders.customer_id accelerates lookups of a single customer’s orders.

How do I verify an index is used?

Run EXPLAIN or check the "query_plan" in the job statistics. A stage labelled SEARCH_INDEX_SCAN indicates index use.

Why How to CREATE INDEX in BigQuery is important

How to CREATE INDEX in BigQuery Example Usage


-- Accelerate lookup for a single customer’s orders
CREATE SEARCH INDEX idx_orders_customer_id
ON ecommerce.Orders (customer_id);

-- Query now leverages the index
SELECT id, order_date, total_amount
FROM ecommerce.Orders
WHERE customer_id = 42;

How to CREATE INDEX in BigQuery Syntax


CREATE [OR REPLACE] [SEARCH] INDEX [IF NOT EXISTS] index_name
ON project.dataset.table_name ( column1 [, column2 ... ] )
[OPTIONS (
  field_length = value,
  include_null_keys = bool
)];

Common Mistakes

Indexing low-selectivity columns such as “status”. The index adds storage cost but offers little benefit because most rows match the filter. Index high-selectivity columns instead.
Forgetting IF NOT EXISTS in automation scripts. Re-running the DDL raises an error and breaks pipelines. Add IF NOT EXISTS or use OR REPLACE.

Frequently Asked Questions (FAQs)

Does BigQuery automatically maintain the index?

Yes. Inserts, updates, and deletes propagate to the index synchronously, so no manual maintenance is required.

Can I index nested or repeated fields?

Currently, SEARCH indexes support simple and array columns but not nested STRUCT fields. Flatten nested data into top-level columns first.

How long does index creation take?

Creation time depends on table size. Expect roughly one minute per 10 GB of data, but BigQuery builds the index in the background without blocking reads and writes.