Appendix B: Quick Facts

This appendix presents a reference for several of SQL Server 2005’s important system and database maximum limits.

Table B-1: System Maximum Limits

Category	Capacity
Maximum addressable memory	32TB (64-bit) 64GB (32-bit using PAE)
Maximum number of processors	64 (64-bit) 32 (32-bit)
Maximum nodes for cluster	8
SQL Server instances per server	50
Locks per instance	Limited only by memory (64-bit) 2,147,483,647 (32-bit)

Table B-2: Database Maximum Limits

Category	Capacity
Databases per server	32,767
Database size	1,048,516TB
Files per database	32,767
File groups per database	265
File size (data)	32TB
File size (log)	32TB
Objects in a database	2,147,483,647
Identifier length	128

Table B-3: Tables

Category	Capacity
Tables per database	Limited by the number of objects in a database
Rows per table	Limited by available storage
PRIMARY KEY constraints per table	1
FOREIGN KEY constraints per table	253
References per table	253
Triggers per table	Limited by the number of objects in a database
Clustered indexes per table	1
Nonclustered indexes per table	249
UNIQUE constraints per table	249 nonclustered, 1 clustered

Table B-4: Columns

Category	Capacity
Columns per index	16
Columns per primary key	16
Columns per foreign key	16
Columns per table	1024
Index key size	900 bytes
Bytes per character or binary column	8000
Bytes per text, ntext, or image column	2GB
Bytes per row	8060
Bytes per index	900
Bytes per primary key	900
Bytes per foreign key	900

Table B-5: T-SQL Maximum Limits

Category	Capacity
Batch size	65,536 multiplied by the network packet size
Tables per SELECT statement	256
Bytes in source text of a stored procedure	Lesser of batch size or 250MB
Parameters per stored procedure	1024
Nested subqueries	32
Nested trigger levels	32
Columns per SELECT statement	4096
Columns per INSERT statement	1024