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Maximum Settings Constants

Applies to: Windows | Windows Server

Maximum Settings Constants

These constants provide the maximum settings that are allowed on items in an ESE database.

Constant/value

Description

JET_BASE_NAME_LENGTH
3

Sets the length for the prefix used to name files that are used by the database engine. This length is applicable to the name set for the JET_paramBaseName system parameter.

JET_MAX_COMPUTERNAME_LENGTH
15

Sets the maximum length for JET_SIGNATURE.

JET_cbBookmarkMost
256

The default maximum size of a bookmark. This is valid when the key size is left at its default value.

JET_cbBookmarkMostMost
2000

The maximum size of a bookmark when esent is configured to have the largest keys possible.

Windows 7: JET_cbBookmarkMostMost is introduced in Windows 7.

JET_cbNameMost
64

The maximum length of a object, column, index, or property name.

Note  If Unicode, the value is 128.

JET_cbFullNameMost
255

The maximum length of a "name.name.name..." construct.

Note  If Unicode, the value is 510.

JET_cbColumnLVPageOverhead
82

This number can be used to compute the maximum amount of a BLOB that can be stored by the database engine on a single database page. The formula is max size = JET_paramDatabasePageSize–JET_cbColumnLVPageOverhead.

This value is now obsolete. The long-value chunk size should be retrieved with the JET_paramLVChunkSizeMost parameter.

JET_cbColumnMost
255

The maximum size of non-long-value column data.

JET_cbLVDefaultValueMost
255

The maximum size of a long-value (LongBinary or LongText) column default value.

JET_cbKeyMost
255

The default maximum size of a sort or index key.

JET_cbKeyMostMost
2000

The maximum configurable size of a sort or index key for any page size. (See JET_INDEXCREATE2.cbKeyMost)

Windows 7: JET_cbKeyMostMost is introduced in the Windows 7 operating system.

JET_cbKeyMost2KBytePage
500

The maximum allowable maximum configurable size for an index key in a database using 2048 byte pages. See JET_INDEXCREATE for more information.

Windows Vista: JET_cbKeyMost2KBytePage is introduced in the Windows Vista operating system.

JET_cbKeyMost4KBytePage
1000

The maximum allowable maximum configurable size for an index key in a database using 4096 byte pages. See JET_INDEXCREATE for more information.

Windows Vista: JET_cbKeyMost4KBytePage is introduced in Windows Vista.

JET_cbKeyMost8KBytePage
2000

The maximum allowable maximum configurable size for an index key in a database using 8192 byte pages. See JET_INDEXCREATE for more information.

Windows Vista:  JET_cbKeyMost8KBytePage is introduced in Windows Vista

JET_cbKeyMostMin
255

The minimum allowable maximum size for an index key. See JET_INDEXCREATE for more information.

Windows Vista:  JET_cbKeyMostMin is introduced in Windows Vista.

JET_cbLimitKeyMost
256

The maximum key size when the key is formed by using a limit grbit, such as JET_bitStrLimit, which is used in the JetMakeKey function.

JET_cbPrimaryKeyMost
255

The maximum size of the primary index. This is now obsolete.

JET_cbSecondaryKeyMost
255

The maximum size of the secondary index. This is now obsolete.

JET_ccolKeyMost
12

The maximum number of components in a sort or index key.

Windows Vista:  In Windows Vista and later versions of Windows the value is 16.

JET_ccolMost
0x0000fee0

The maximum number of columns allowed in a table.

Windows XP:  The value 0x0000fee0 is used in Windows XP and later and later versions of Windows

Windows 2000:  The value 0x00007ffe is used in Windows 2000.

JET_ccolFixedMost
0x0000007f

The maximum number of fixed columns allowed in a table, currently 127.

JET_ccolVarMost
0x00000080

The maximum number of variable-length columns that can be contained in a table, currently 128.

JET_ccolTaggedMost
( JET_ccolMost - 0x000000ff )

The maximum number of tagged columns that can be contained in a table, currently 64993.

Requirements

Requirement Value

Client

Requires Windows Vista, Windows XP, or Windows 2000 Professional.

Server

Requires Windows Server 2008, Windows Server 2003, or Windows 2000 Server.

Header

Declared in Esent.h.