Quotas & limits

This page describes production quotas and limits for Cloud Spanner. The difference between a quota and a limit is that a limit cannot be adjusted, whereas you can request a quota increase.

The quota and limit values are subject to change.

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.

  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 TB1

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 2,560
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

7

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

Size of data per row

4 GB

Includes the top-level row and all of its interleaved child and index rows

Indexes

Value Limit
Indexes per database 5,120
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 size3 1 MB
Rate limit for administrative actions4

5 per second per project per user

(averaged over 100 seconds)

Request limits

Value Limit
Request size other than for commits5 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 a new record may count as five mutations, if values are inserted into five columns. Delete and delete range operations count as one mutation regardless of the number of columns affected. Deleting a row from a parent table that has the ON DELETE CASCADE annotation is also counted as one mutation regardless of the number of interleaved child rows present. The exception to this is if there are secondary indexes defined on rows being deleted, then the changes to the secondary indexes will be counted individually. For example, if a table has 2 secondary indexes, deleting a range of rows in the table will count as 1 mutation for the table, plus 2 mutations for each row that is deleted because the rows in the secondary index might be scattered over the key-space, making it impossible for Cloud Spanner to call a single delete range operation on the secondary indexes. Secondary indexes include the foreign keys backing indexes.

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.