This page describes production limits for Cloud Spanner.

These values are subject to change.

Limits Amount
Databases per instance 100
Tables per database 2,048
Indexes per database 4,096
Indexes per table 32
Columns per table 1,024
Size of data per column 10 MB
Storage size per node 2 TB 1
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, etc.
Commit size (including indexes) 100 MB
Mutations per commit (including indexes) 2 20,000
Request size other than for commits 3 10 MB
Schema size 10 MB
Schema change size 10 MB
Administrative actions request size (not including the actions above) 1 MB
Concurrent reads per session 100
Sessions per database per node 10,000
Rate for administrative actions 5 per second per project
(averaged over 100 seconds)
Database ID length 2-30 characters
Table name length 1-128 characters
Column name length 1-128 characters
Index name length 1-128 characters
Maximum query statement length 1 million characters
Number of columns in a table key 16
Includes key columns shared with any parent table
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
Total size of a table or index key 8 KB
Includes the size of all columns that make up the key

Limits Notes

1. To provide high availability and low latency for accessing a database, Cloud Spanner requires that there is a node for every 2 TB of data in the database. For example, if you have a database of size 3.5 TB, you need to provision at least 2 nodes. That will handle your database until it grows to 4 TB. Once your database reaches 4 TB, 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. This includes requests for creating a database, updating a database, reading, streaming reads, executing SQL queries, and executing streaming SQL queries.

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Cloud Spanner Documentation