Quotas & limits

This page describes production limits for Cloud Spanner.

These values are subject to change.

Note: Storage and network usage are calculated in binary gigabytes (GB), where 1 GB is 2³⁰ bytes. This unit of measurement is also known as a gibibyte (GiB). Similarly, 1 TB is 2⁴⁰ bytes, or 1,024 GB.

Checking your quotas

To check the current quotas for resources in your project, use the Google Cloud Console:

Check your quotas

Increasing your quotas

As your use of Cloud Spanner expands over time, your quotas can increase accordingly. If you expect a notable upcoming increase in usage, you should make your request a few days in advance to ensure your quotas are adequately sized.

Note: To request additional quotas, your user account must have the serviceusage.quotas.update permission. This permission is included by default for the following predefined roles: Owner, Editor, and Quota Administrator.

1. Go to the Quotas page in the Cloud Console.

   Go to the Quotas page

2. Select Cloud Spanner API in the Service dropdown list.

   If you do not see Cloud Spanner API, the Cloud Spanner API has not been enabled.

3. Select the quotas you want to change.

4. Click Edit Quotas.

5. Fill in your name, email, and phone number and click Next.

6. Fill in your quota request and click Submit request.

You will receive a response from the Cloud Spanner team within 48 hours of your request.

Instance limits

Value	Limit
Instance ID length	2 to 64 characters

Database limits

Value	Limit
Databases per instance	100
Database ID length	2 to 30 characters
Storage size per node	2 TB^1

Backup and restore limits

Value	Limit
Number of ongoing create backup operations per database	1
Number of ongoing restore database operations per instance (in the instance of the restored database, not the backup)	1
Maximum retention time of backup	1 year (including the extra day in a leap year)

Schema limits

DDL statements

Value	Limit
DDL statement size for a single schema change	10 MB
DDL statement size for a database's entire schema, as returned by GetDatabaseDdl	10 MB

Tables

Value	Limit
Tables per database	2,048
Table name length	1 to 128 characters
Columns per table	1,024
Column name length	1 to 128 characters
Size of data per column	10 MB
Number of columns in a table key	16 Includes key columns shared with any parent table
Table interleaving depth	6 A top-level table with child table(s) has depth 1. A top-level table with grandchild table(s) has depth 2, and so on.
Total size of a table or index key	8 KB Includes the size of all columns that make up the key

Indexes

Value	Limit
Indexes per database	4,096
Indexes per table	32
Index name length	1 to 128 characters
Number of columns in an index key	16 The number of indexed columns (except for STORING columns) plus the number of primary key columns in the base table

Query limits

Value	Limit
Columns in a GROUP BY clause	1000
Function calls	1000
Joins	15
Nested function calls	75
Nested GROUP BY clauses	35
Nested subquery expressions	25
Nested subselect statements	60
Parameters	950
Query statement length	1 million characters
STRUCT fields	1000
Subquery expression children	40
Unions in a query	200

Limits for creating, reading, updating, and deleting data

Value	Limit
Commit size (including indexes)	100 MB
Concurrent reads per session	100
Mutations per commit (including indexes)^2	20,000
Concurrent Partitioned DML statements per database	20,000

Administrative limits

Value	Limit
Administrative actions request size^3	1 MB
Rate limit for administrative actions^4	5 per second per project per user (averaged over 100 seconds)

Request limits

Value	Limit
Request size other than for commits^5	10 MB

Notes

1. To provide high availability and low latency for accessing a database, Cloud Spanner requires 1 node for every 2 TB of data in the database. For example, if your instance has 1 database that stores 3.5 TB of data, you need to provision at least 2 nodes. Those nodes will keep the instance below the limit until the database grows to 4 TB. After your database reaches that size, you need to add another node to allow the database to grow. Otherwise, writes to the database will fail. For a smooth growth experience, add nodes before this limit is reached for your database.

2. Insert and update operations count with the multiplicity of the number of columns they affect. For example, inserting values into one key column and four non-key columns count as five mutations total for the insert. Delete and delete range operations count as one mutation regardless of the number of columns affected.

3. The limit for an administrative action request excludes commits, requests listed in note 5, and schema changes.

4. This rate limit includes all calls to the admin API, which includes calls to poll long-running operations on an instance, database, or backup.

5. This limit includes requests for creating a database, updating a database, reading, streaming reads, executing SQL queries, and executing streaming SQL queries.