Adaptive Server specifications

This section provides Adaptive Server specifications for Digital UNIX.

**Table 2-7: Adaptive Server specifications for Digital UNIX**
Hardware
Processor	64-bit Alpha
Recommended RAM for Adaptive Server	92MB	47,104 2K pages
Memory per user connection	Approx. 250K	With default stack size, packet size, and user log cache size
Default user stack size	73,728 bytes	Minimum 34,816 bytes
Maximum CPUs per server	128

Database specifications
Databases per Adaptive Server	32,767	Practical limit is approximately 100
Maximum database size	2⁴³(8TB)	Minus overhead for system databases
Minimum allowable sybsystemprocs database	100MB	Required for an upgrade
Maximum size of a database device (disk partition)	2²⁴(32GB)	If the Operating System supports file sizes up to 32GB, then Adaptive Server supports file system devices up to 32GB
Maximum number of database devices per server	256
Maximum number of devices or device pieces per database	Unlimited
Maximum number of segments per database	31
Maximum number of login IDs per server	2147516416
Maximum number of users per database	2146484223
Maximum number of groups per database	1032193
pubs2 database	2MB 4MB	Minimum required for a new installation Free space required for an upgrade
pubs3 database	2MB 4MB	Minimum required for a new installation Free space required for an upgrade
interpubs database	2MB 4MB	Minimum required for a new installation Free space required for an upgrade
jpubs database	2MB 4MB	Minimum required for a new installation Free space required for an upgrade

Table specifications
User objects per database	2³¹ – 100
Indexes per table	250 (one clustered index)
Rows per table	Limited by available storage	Maximum 2³²
Columns per composite index	31
Creation of clustered index	1.2*(x + y) x = total data space in table, y = sum of space of all nonclustered indexes on table, and 20 percent overhead for logging	For sorted data, approximately 20 percent of the table size needed
Characters per database object name	30

Query specifications
Maximum number of tables in a “union” query	256
Maximum number of databases participating in one transaction	16	Includes database where transaction began, all databases changed during transaction, and tempdb, if it is used for results or worktables
Practical number of databases participating in one query	16	Includes each occurrence of each database queried and tempdb, if it is used for results or worktables
Maximum number of tables participating in a query	64	Maximum of 50 user tables, including result tables, tables referenced by views (the view itself is not counted) correlations and self-joins; maximum of 14 worktables
Maximum number of tables with referential integrity constraints for a query	192

Procedure specifications
Number of buffers and procedure buffers	Configurable	Limited by amount of RAM and maximum size of shared memory segment
Minimum memory required per stored procedure	2K
Maximum number of parameters per stored procedure	2048

Adaptive Server 12.5 extended-limit capabilities vary by type of table and the database logical page size. Table 2-8 lists the column and row limits for allpages-locked (APL) tables.

**Table 2-8: Allpages-locked (APL) tables**
Maximum APL table limits	Number of columns	Column size 2K page	Column size 4K page	Column size 8K page	Column size 16K page
Fixed-length column	1024	1960 bytes	4008 bytes	8104 bytes	16296 bytes
Variable-length column	254	1948 bytes	3988 bytes	8068 bytes	16228 bytes

Table 2-9 lists the column and row limits for data-only-locked (DOL) tables.

**Table 2-9: Data-only-locked (DOL) tables**
Maximum DOL table limits	Number of columns	Column size 2K page	Column size 4K page	Column size 8K page	Column size 16K page
Fixed-length column	1024	1958 bytes	4006 bytes	8102 bytes	16294 bytes
Variable-length column	1024	1954 bytes	4002 bytes	8089 bytes	16290 bytes

Database space requirements depend upon the logical page size of the server. Table 2-10 lists the minimum size for each database.

**Table 2-10: Database requirements for varying page sizes**
Databases	2K page	4K page	8K page	16K page
Default database size	2MB	4MB	8MB	16MB
master database	6MB	12MB	24MB	48MB
model database	3MB	4MB	8MB	16MB
tempdb database	3MB	4MB	8MB	16MB

Larger logical page sizes can contain more data. Table 2-11 lists the maximum data for each logical page size.

**Table 2-11: Data limits for tables according to page size**
Tables	2K page	4K page	8K page	16K page
Maximum number of data bytes per text or image file	1800	3600	7650	16200
Bytes per index key	600	1250	2600	5300
User-visible row length DOL table	1958	4006	8102	16294
User-visible row length APL table	1960	4008	8104	16296